Biomass-derived carbon/γ-MnO2 nanorods/S composites prepared by facile procedures with improved performance for Li/S batteries

The promising prospects of the Li/S battery, due to its theoretical energy density of about 2500 Wh kg─1, are severely limited by two main weaknesses: the poor conductivity of S and the solubility of the polysulphides in the electrolyte. A combination of carbon and transition metal oxides is the best option for mitigating both of these shortcomings simultaneously. In this work, we use hydrothermally-tailored γ-MnO2 nanorods combined with an activated biomass-derived carbon, which is an inexpensive material and easy to prepare. This strategy was also followed for a AC/MnO2/S composite, a preparation of which was made by grinding; this is the simplest method for practical applications. More complex procedures for the formation of in situ hydrothermal MnO2 nanorods gave similar results to those obtained from grinding. Compared with the AC/S composite, the presence of MnO2 markedly increased the delivered capacity and improved the cycling stability at both low (0.1 C) and high (1 C) currents. This behaviour results from a combination of two main effects: firstly, the MnO2 nanorods increase the electrical conductivity of the electrode, and secondly, the small particle size of the oxide can enhance the chemisorption properties and facilitate a redox reaction with polysulphides, more efficiently blocking their dissolution in the electrolyte

Importance Sampling for Objetive Funtion Estimations in Neural Detector Traing Driven by Genetic Algorithms

To train Neural Networks (NNs) in a supervised way, estimations of an objective function must be carried out. The value of this function decreases as the training progresses and so, the number of test observations necessary for an accurate estimation has to be increased. Consequently, the training computational cost is unaffordable for very low objective function value estimations, and the use of Importance Sampling (IS) techniques becomes convenient. The study of three different objective functions is considered, which implies the proposal of estimators of the objective function using IS techniques: the Mean-Square error, the Cross Entropy error and the Misclassification error criteria. The values of these functions are estimated by IS techniques, and the results are used to train NNs by the application of Genetic Algorithms. Results for a binary detection in Gaussian noise are provided. These results show the evolution of the parameters during the training and the performances of the proposed detectors in terms of error probability and Receiver Operating Characteristics curves. At the end of the study, the obtained results justify the convenience of using IS in the training

Effective cancer immunotherapy by natural mouse conventional type-1 dendritic cells bearing dead tumor antigen

BACKGROUND: The manipulation of dendritic cells (DCs) for cancer vaccination has not reached its full potential, despite the revolution in cancer immunotherapy. DCs are fundamental for CD8+ T cell activation, which relies on cross-presentation of exogenous antigen on MHC-I and can be fostered by immunogenic cancer cell death. Translational and clinical research has focused on in vitro-generated monocyte-derived DCs, while the vaccination efficacy of natural conventional type 1 DCs (cDC1s), which are associated with improved anti-tumor immunity and specialize on antigen cross-presentation, remains unknown. METHODS: We isolated primary spleen mouse cDC1s and established a protocol for fast ex vivo activation and antigen-loading with lysates of tumor cells that underwent immunogenic cell death by UV irradiation. Natural tumor antigen-loaded cDC1s were transferred and their potential for induction of endogenous CD8+ and CD4+ T cell responses in vivo, cancer prevention and therapy were assessed in three grafted cancer models. Further, we tested the efficacy of natural cDC1 vaccination in combination and comparison with anti-PD-1 treatment in two "wildtype" tumor models not expressing exogenous antigens. RESULTS: Herein, we reveal that primary mouse cDC1s ex vivo loaded with dead tumor cell-derived antigen are activated and induce strong CD8+ T cell responses from the endogenous repertoire upon adoptive transfer in vivo through tumor antigen cross-presentation. Notably, cDC1-based vaccines enhance tumor infiltration by cancer-reactive CD8+ and CD4+ T cells and halt progression of engrafted cancer models, including tumors that are refractory to anti-PD-1 treatment. Moreover, combined tumor antigen-loaded primary cDC1 and anti-PD-1 therapy had strong synergistic effects in a PD-1 checkpoint inhibition susceptible cancer model. CONCLUSIONS: This preclinical proof-of-principle study is first to support the therapeutic efficacy of cancer immunotherapy with syngeneic dead tumor cell antigen-loaded mouse cDC1s, the equivalents of the human dendritic cell subset that correlates with beneficial prognosis of cancer patients. Our data pave the way for translation of cDC1-based cancer treatments into the clinic when isolation of natural human cDC1s becomes feasible.Work in the DS laboratory is funded by the CNIC and grant SAF2016–79040-R from Ministerio de Ciencia, Innovación e Universidades (MCIU), Agencia Estatal de Investigación and Fondo Europeo de Desarrollo Regional (FEDER); B2017/BMD-3733 Immunothercan-CM from Comunidad de Madrid; RD16/0015/0018-REEM from FIS-Instituto de Salud Carlos III, MICINN and FEDER; Acteria Foundation; Constantes y Vitales prize (Atresmedia); La Marató de TV3 Foundation (201723); and the European Research Council (ERC-2016-Consolidator Grant 725091). Work at the IM laboratory is funded by grants from MCIU (SAF2014–52361-R and SAF2017–83267-C2–1-R) and by European Commission VII Framework and Horizon 2020 programs (AICR), Fundación de la Asociación Española Contra el Cáncer (AECC), and Fundación BBVA. SKW is supported by a European Molecular Biology Organization Long-term Fellowship (grant ALTF 438–2016) and a CNIC-International Postdoctoral Program Fellowship (grant 17230–2016). SCK is a recipient of a FPU fellowship (FPU16/03142) from the Spanish Ministry of Education, Culture and Sports. IM and DS labs are funded by the European Commission (635122-PROCROP H2020). The CNIC is supported by the MCIU and the Pro-CNIC Foundation, and is a Severo Ochoa Center of Excellence (SEV-2015-0505). AGRADECIENTOS: ProCNIC; Severo Ochoa (SEV-2015-0505)S

Benzo-dipteridine derivatives as organic cathodes for Li- and Na-ion batteries

Organic-based electrodes for Li- and Na-ion batteries present attractive alternatives to commonly applied inorganic counterparts which can often carry with them supply-chain risks, safety concerns with thermal runaway, and adverse environmental impact. The ability to chemically direct the structure of organic electrodes through control over functional groups is of particular importance, as this provides a route to fine-tune electrochemical performance parameters. Here, we report two benzo-dipteridine derivatives, BF-Me2 and BF-H2, as high-capacity electrodes for use in Li- and Na-ion batteries. These moieties permit binding of multiple Li-ions per molecule while simultaneously ensuring low solubility in the supporting electrolyte, often a precluding issue with organic electrodes. Both display excellent electrochemical stability, with discharge capacities of 142 and 182 mAh g–1 after 100 cycles at a C/10 rate and Coulombic efficiencies of 96% and ∼ 100% demonstrated for BF-Me2 and BF-H2, respectively. The application of a Na-ion cell has also been demonstrated, showing discharge capacities of 88.8 and 137 mAh g–1 after 100 cycles at a C/2 rate for BF-Me2 and BF-H2, respectively. This work provides an encouraging precedent for these and related structures to provide versatile, high-energy density, and long cycle-life electrochemical energy storage materials

Highly graphitized carbon nanosheets with embedded Ni nanocrystals as anode for Li-ion batteries

A C/Ni composite was prepared via thermal decomposition of a nickel oleate complex at 700 °C, yielding disperse Ni nanocrystals with an average size of 20 nm, encapsulated by carbon nanosheets as deduced from transmission electron microscopy (TEM) images and confirmed from X-ray photoelectron spectroscopy (XPS). Furthermore, the X-ray diffraction pattern revealed a good ordering of the carbon layers, forced by the Ni encapsulation to adopt a bending structure. Considering the close interaction between the graphitized framework and the metallic nanoparticles we have studied the properties of the composite as an anode for Li-ion batteries. Compared with other nanostructured synthetic carbons, this carbon composite has a low voltage hysteresis and a modest irreversible capacity value, properties that play a significant role in its behaviour as electrodes in full cell configuration. At moderate rate values, 0.25 C, the electrode delivers an average capacity value around 723 mAh·g−1 on cycling, among the highest values so far reported for this carbon type. At higher rate values, 1 C, the average capacity values delivered by the cell on cycling decrease, around 205 mAh·g−1, but it maintains good capacity retention, a coulombic efficiency close to 100% after the first cycles and recovery of the capacity values when the rate is restored from 3 to 0.1 C

El modelo de Richard Florida y la creatividad en España. Una aproximación autonómica y provincial

La noción de Clase Creativa ha alcanzado una gran notoriedad en el ámbito de las ciencias sociales desde que Florida publicase The Rise of Creative Class en el año 2002. A partir de las investigaciones de Florida sobre la clase creativa, aparecieron críticas, como las de Peck (2005), Scott Allen (2006) o Uzzi y Spiro (2005). Actualmente, para entender las clases creativas hay que hacer referencia a la “economía creativa” y a las “industrias creativas”. El autor que ha popularizado la expresión de “economía creativa” es Hawkins (2005), el cual observó a finales de los años noventa, que se estaba perdiendo en muchos negocios el hecho de tener ideas. La otra expresión, “industrias creativas”, fue impulsada por la UNESCO (2005) para sustituir el concepto de “industrias culturales”

Chemical abundances of Seyfert 2 AGNs, I: comparing oxygen abundances from distinct methods using SDSS

We compare the oxygen abundance (O/H) of the narrow-line regions (NLRs) of Seyfert 2 AGNs obtained through strong-line methods and from direct measurements of the electron temperature (Te-method). The aim of this study is to explore the effects of the use of distinct methods on the range of metallicity and on the mass-metallicity relation of active galactic nuclei (AGNs) at low redshifts (z<~0.4). We used the Sloan Digital Sky Survey (SDSS) and NASA/IPACExtragalactic Database (NED) to selected optical (3000Fil: Dors, Oli L.. Universidade Do Vale Do Paraiba; BrasilFil: de Freitas Rosa, Morsyleide. Universidade Do Vale Do Paraiba; BrasilFil: Amores, E. B.. Universidade Estadual de Feira de Santana; BrasilFil: Almarcha Pérez, Martha Ayelén. Instituto de Astrofísica de Andalucía - Csic; EspañaFil: Cardaci, Monica Viviana. Instituto de Astrofísica de la Plata (conicet- Universidad Nacional de la Plata); Argentina. Universidad Nacional de La Plata; ArgentinaFil: Hägele, Guillermo Federico. Universidad Nacional de La Plata; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Armah, M.. Universidade Do Vale Do Paraiba; BrasilFil: Krabbe, A. C.. Universidade Do Vale Do Paraiba; BrasilFil: Ruiz Faúndez, Giovanni Patricio. Laboratorio Nacional de Astrofisica, Itajuba; Brasi