Redox-Active Metallacarborane-Decorated Octasilsesquioxanes. Electrochemical and Thermal Properties

Polyanionic and electroactive hybrids based on octasilsesquioxanes bearing metallacarborane units are developed. They show remarkable solubility in organic solvents and outstanding thermal stability. The metallacarboranes act as independent units simultaneously undergoing the reversible redox process.We acknowledge support by MINECO [Grants CTQ2013- 44670-R, CTQ2012-32436, and CTQ2015-64436-P and the “Severo Ochoa” Program for Centers of Excellence in R&D (SEV-2015-0496)] and Generalitat de Catalunya (Grant 2014/ SGR/149). J.C.-G. thanks to the CSIC for an intramural grant. V.S.-A. thanks MICINN (Grant CTQ2010-16237) for the FPI grant.Peer reviewe

Two-Photon Spectroscopy Between States of Opposite Parities

Magnetic- and electric-dipole two-photon absorption (MED-TPA), recently introduced as a new spectroscopic technique for studying transitions between states of opposite parities, is investigated from a theoretical point of view. A new approximation, referred to as {\it weak quasi-closure approximation}, is used together with symmetry adaptation techniques to calculate the transition amplitude between states having well-defined symmetry properties. Selection rules for MED-TPA are derived and compared to selection rules for parity-forbidden electric-dipole two-photon absorption (ED-TPA).Comment: 7 pages, Revtex File, to be published in Physical Review

H2 Production from Formic Acid Using Highly Stable Carbon-Supported Pd-Based Catalysts Derived from Soft-Biomass Residues: Effect of Heat Treatment and Functionalization of the Carbon Support

The production of hydrogen from liquid organic hydrogen carrier molecules stands up as a promising option over the conventional hydrogen storage methods. In this study, we explore the potential of formic acid as a convenient hydrogen carrier. For that, soft-biomass-derived carbon-supported Pd catalysts were synthesized by a H3PO4-assisted hydrothermal carbonization method. To assess the impact of the properties of the support in the catalytic performance towards the dehydrogenation of formic acid, three different strategies were employed: (i) incorporation of nitrogen functional groups; (ii) modification of the surface chemistry by performing a thermal treatment at high temperatures (i.e., 900 °C); and (iii) combination on both thermal treatment and nitrogen functionalization. It was observed that the modification of the carbon support with these strategies resulted in catalysts with enhanced performance and outstanding stability even after six consecutive reaction cycles, thus highlighting the important effect of tailoring the properties of the support.This work was financed by the MICINN, FEDER (RTI2018-095291-B-I00). J.C.-G. is grateful for her pre-doctoral scholarship (GRISOLIA/2018/105), funded by the Generalitat Valenciana. M.N.-G. would like to thank the Plan GenT project (CDEIGENT/2018/027) for their financial support. D.S.-T. thanks Vicerrectorado de Investigación y Transferencia de Conocimiento de la Universidad de Alicante for their financial support (GRE19-16)

Highly Stable N-Doped Carbon-Supported Pd-Based Catalysts Prepared from Biomass Waste for H2 Production from Formic Acid

Excellent Pd supported on carbon catalysts for the dehydrogenation of formic acid were synthesized from a lignocellulosic biomass residue. The preparation of the carbon support consisted of a H3PO4-assisted hydrothermal carbonization (HTC) and activation of a hemp residue and subsequent nitrogen functionalization. It was observed that the presence of nitrogen groups influenced both the size and the electronic properties of the Pd nanoparticles, which ultimately affected their catalytic properties. Furthermore, the catalytic performance also depended on the synthesis conditions used in the preparation of the catalysts (i.e., reduction of the Pd nanoparticles with NaBH4 prior to the catalytic test or in situ reduction). The best-performance catalysts (Pd/N-HTC (n.r.)), which were prepared by in situ reduction of the nanoparticles, displayed a remarkable catalytic activity with a very high TOF number of 8365 h–1 (TOF value calculated for the 2nd catalytic run and expressed per surface Pd atom) and outstanding stability during 6 consecutive reaction cycles, although the initial activity is maintained for 12 cycles. The catalytic system studied is among the most stable ever reported Pd-based heterogeneous catalysts for the dehydrogenation of formic acid.This work was financed by the MICINN, FEDER (RTI2018-095291-B-I00). J.C.-G. acknowledges her predoctoral scholarship (GRISOLIA/2018/105) funded by the Generalitat Valenciana. M.N.-G. thanks the Plan GenT project (CDEIGENT/2018/027) for the financial support. D.S.-T. thanks the MICINN for the “Juan de la Cierva” contract (IJCI-2016-27636)

Synthetic Fatty Acids Prevent Plasmid-Mediated Horizontal Gene Transfer

Bacterial conjugation constitutes a major horizontal gene transfer mechanism for the dissemination of antibiotic resistance genes among human pathogens. Antibiotic resistance spread could be halted or diminished by molecules that interfere with the conjugation process. In this work, synthetic 2-alkynoic fatty acids were identified as a novel class of conjugation inhibitors. Their chemical properties were investigated by using the prototype 2-hexadecynoic acid and its derivatives. Essential features of effective inhibitors were the carboxylic group, an optimal long aliphatic chain of 16 carbon atoms, and one unsaturation. Chemical modification of these groups led to inactive or less-active derivatives. Conjugation inhibitors were found to act on the donor cell, affecting a wide number of pathogenic bacterial hosts, including Escherichia, Salmonella, Pseudomonas, and Acinetobacter spp. Conjugation inhibitors were active in inhibiting transfer of IncF, IncW, and IncH plasmids, moderately active against IncI, IncL/M, and IncX plasmids, and inactive against IncP and IncN plasmids. Importantly, the use of 2-hexadecynoic acid avoided the spread of a derepressed IncF plasmid into a recipient population, demonstrating the feasibility of abolishing the dissemination of antimicrobial resistances by blocking bacterial conjugation.The work performed by the F.D.L.C. group was supported by grants BFU2011-26608 from the Spanish Ministry of Economy and Competitiveness and 612146/FP7-ICT-2013-10 and 282004/FP7-HEALTH-2011-2.3.1-2 from the European Seventh Framework Programme. The work performed by M.G. was supported by a Ph.D. fellowship from the University of Cantabria. The work performed by D.J.S.-R. was supported by the National Center for Research Resources and the National Institute of General Medical Sciences of the National Institutes of Health through grant no. 5P20GM103475-13 and the Interamerican University of Puerto Rico. The work performed by J.C.-G. was supported by an EMBO postdoctoral fellowship, ASTF 402-2010. The work performed by Biomar Microbial Technologies was supported by grant 282004/FP7-HEALTH-2011-2.3.1-2 from the European Seventh Framework Programme.USD 2,190 APC fee funded by the EC FP7 Post-Grant Open Access PilotPeer reviewe

Improvements in CO2 Booster Architectures with Different Economizer Arrangements.

CO2 transcritical booster architectures are widely analyzed to be applied in centralized commercial refrigeration plants in consonance with the irrevocable phase-out of HFCs. Most of these analyses show the limitations of CO2 cycles in terms of energy e ciency, especially in warm countries. From the literature, several improvements have been proposed to raise the booster e ciency in high ambient temperatures. The use of economizers is an interesting technique to reduce the temperature after the gas cooler and to improve the energy e ciency of transcritical CO2 cycles. The economizer cools down the high pressure’s line of CO2 by evaporating the same refrigerant extracted from another point of the facility. Depending on the extraction point, some configurations are possible. In this work, di erent booster architectures with economizers have been analyzed and compared. From the results, the combination of the economizer with the additional compressor allows obtaining energy savings of up to 8.5% in warm countries and up to 4% in cold countries with regard to the flash-by-pass arrangement and reduce the volumetric displacement required of the MT compressors by up to 37%

The influence of tides on the exchange through the Strait of Gibraltar and on properties of the Mediterranean Sea

A. Ishlinsky Institute for Problems in Mechanics, Rusi

ECM-Regulator timp Is Required for Stem Cell Niche Organization and Cyst Production in the Drosophila Ovary.

The extracellular matrix (ECM) is a pivotal component adult tissues and of many tissue-specific stem cell niches. It provides structural support and regulates niche signaling during tissue maintenance and regeneration. In many tissues, ECM remodeling depends on the regulation of MMP (matrix metalloproteinase) activity by inhibitory TIMP (tissue inhibitors of metalloproteinases) proteins. Here, we report that the only Drosophila timp gene is required for maintaining the normal organization and function of the germline stem cell niche in adult females. timp mutant ovaries show reduced levels of both Drosophila Collagen IV α chains. In addition, tissue stiffness and the cellular organization of the ovarian niche are affected in timp mutants. Finally, loss of timp impairs the ability of the germline stem cell niche to generate new cysts. Our results demonstrating a crucial role for timp in tissue organization and gamete production thus provide a link between the regulation of ECM metabolism and tissue homeostasis.We thank J.C.-G. Hombría and A. Page-McCaw for fly stocks and the Developmental Studies Hybridoma Bank from the University of Iowa (USA) for antibodies. The Proteomics Facility at the CNB (CSIC; Madrid, Spain) provided technical support with the iTRAQ analysis. The TEM analysis was performed at the CIC, University of Granada. The help of J. Garrido with S5 Fig is acknowledged. This work was funded by the Spanish MINECO (Grants BFU2009-08013, BFU2012-35446 to AGR, BFU2010-16669 to MDMB and Consolider CSD-2007-00008 to MDMB and AGR), by the Junta de Andalucía (Proyecto de Excelencia P09-CVI-5058 to MDMB and AGR) and by the European Regional Development Fund (FEDER). JRP was supported by a JAE-Doc contract from the Spanish National Research Council (CSIC) and KF by a Career Development Award from the UK Medical Research Council. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.This is the final version of the article. It first appeared from the Public Library of Science via http://dx.doi.org/10.1371/journal.pgen.100576

Coeovolutionary Threshold Dynamics

We present a generic threshold model for the co-evolution of the structure of a network and the state of its nodes. We focus on regular directed networks and derive equations for the evolution of the system toward its absorbing state. It is shown that the system displays a transition from a connected phase to a fragmented phase that depends on its initial configuration. Computer simulations are performed and confirm the theoretical predictions.Comment: 4 pages, 4 figure

A 3D Peptide/[60]Fullerene Hybrid for Multivalent Recognition

Multivalent ligand presentation is a powerful strategy for the development of specific binders and inhibitors. Peptide/[60]fullerene hybrids have now been synthesized that exploit the complete substitution of the fullerene scaffold to afford globular structures presenting twelve copies of a peptide ligand for the recognition of E-selectin. Fully substituted peptide/[60]fullerene hexakis-adducts offer an excellent opportunity for multivalent protein recognition. In contrast to monofunctionalized fullerene hybrids, peptide/[60]fullerene hexakis-adducts display multiple copies of a peptide in close spatial proximity and in the three dimensions of space. High affinity peptide binders for almost any target can be currently identified by in vitro evolution techniques, often providing synthetically simpler alternatives to natural ligands. However, despite the potential of peptide/[60]fullerene hexakis-adducts, these promising conjugates have not been reported to date. Here we present a synthetic strategy for the construction of 3D multivalent hybrids that are able to bind with high affinity the E-selectin. The here synthesized fully substituted peptide/[60]fullerene hybrids and their multivalent recognition of natural receptors constitute a proof of principle for their future application as functional biocompatible materialsThis work was partially supported by the Spanish Agencia Estatal de Investigación (AEI) [SAF2017-89890-R, PCI2019-103400, PID2020-117143RB-I00, PID2020-114653RB-I00 and PID2020-115120GB-I00], Xunta de Galicia (ED431C 2017/25 and Centro singular de investigación de Galicia accreditation 2019–2022, ED431G 2019/03) and the European Commission (EC) (European Regional Development Fund-ERDF). J.M. thanks the ERC-STG (DYNAP, 677786), ERC-POC (TraffikGene, 838002), Xunta de Galicia (Oportunius Program) and Human Frontier Science Programme Young Investigator Grant (RGY0066/2017) for funding. J.J.R. received a Beatriz Galindo Grant (BEAGAL18-00051) by the Spanish Ministerio de Universidades. I.G. received predoctoral fellowships (ED481A-2018/116 and FPU17/00941). J.C.-G. thanks the Comunidad de Madrid Atracción de Talento program (2018-T2/BMD-10275)S