Optimized polarization build-up times in dissolution DNP-NMR using a benzyl amino derivative of BDPA

The synthesis of two novel BDPA-like radicals, a benzyl amino (BAm-BDPA, 7) and a cyano (CN-BDPA, 5) derivative, is reported and their behaviour as polarizing agents for fast dissolution Dynamic Nuclear Polarization (DNP) is evaluated. The radical 7 is a promising candidate for DNP studies since it is soluble in neat [1-13C]pyruvic acid (PA), and therefore the use of an additional glassing agent for sample homogeneity is avoided. In addition, a 60 mM sample of 7 offers optimum 13C NMR signal enhancements using fairly short polarization times (about 1800 s). It is shown that DNP-NMR measurements using 7 can be performed much more efficiently in terms of the signal enhancement per polarization build-up time unit than when using the reference OX63 or BDPA radicals. These enhanced features are translated to a substantial reduction of polarization times that represents an optimum temporary use of the DNP polarizer and allow economized liquid helium consumption.This research was supported by the DGI Grants “POMAs” (CTQ2010-19501) and “Be-Well” (CTQ2013-40480 R), MINECO (CTQ2012-32436), AGAUR Grant (2014SGR-0017) and MINECO Grant (PTA 2011-5037-I) for the subprogram Personal T´ecnico de Apoyo. We also thank the Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), the Consejo Superior de Investigaciones Cient´ıcas for the JAE Grant, and Amable Bernab´e for his work in MALDI spectrometry. NMR studies were carried out at the joint NMR facility of the Universitat Aut`onoma de Barcelona and CIBER-BBN (Cerdanyola del Vall`es).Peer reviewe

Novel PTM-TEMPO biracial for fast dissolution dynamic nuclear polarization

The synthesis and characterization of a novel trityl-TEMPO biradical and the investigation of its properties as Dynamic Nuclear Polarization (DNP) polarizing agent are reported. Comparison with a structurally related monoradical (PTM-TEMPE) or mixtures of the two monoradical components reveals that the biradical has a much higher polarization efficiency and a faster polarization buildup. This offers the possibility of faster recycling further contributing to its efficiency as a polarizing agent

DT-TTF Salts with [Cu(dcdmp)2]−: The Richness of Different Stoichiometries

(DT-TTF)[Cu(dcdmp)(2)] (1), (DT-TTF)(2)[Cu(dcdmp)(2)] (2), and (DT-TTF)(3)[Cu(dcdmp)(2)](2) (3) are three new charge transfer salts obtained by electrocrystallization of the donor DT-TTF (dithiophene-tetrathiafulvalene) with the diamagnetic copper complex [Cu(dcdmp)(2)](-) (dcdmp = 2,3-dicyano-5,6-dimercaptopyrazine). Compounds 1 and 3 crystallize in the triclinic system and consist of out-of-registry layers of mixed stacks of donor and acceptor molecules. (DT-TTF)(2)[Cu(dcdmp)(2)] presents a structure similar to the parent spin-ladder systems with donor stacks arranged in pairs; however, a magnetic spin-ladder behavior is not observed probably due to strong interactions between pairs. Compound 3, despite the mixed nature of the stacks, displays relatively high conductivity (7 S/cm) due to a one-dimensional network of interactions between donors.This work was supported by FCT (Portugal) through contracts PTDC/QEQ-SUP/1413/2012 and UID/Multi/04349/2013 and by DGI, Spain (CTQ2013-40480), the Generalitat de Catalunya (2014SGR0017), the CIBER de Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), promoted by ISCIII, Spain. R. A. L. S. is thankful to FCT for the PhD grant SFRH/BD/86131/2012.Peer reviewe

NMR signal enhancement of > 50 000 times in fast dissolution dynamic nuclear polarization

Herein, we report the synthesis and the study of a novel mixed biradical with BDPA and TEMPO radical units that are covalently bound by an ester group (BDPAesterTEMPO) as a polarizing agent for fast dissolution DNP. The biradical exhibits an extremely high DNP NMR enhancement of >50 000 times, which constitutes one of the largest signal enhancements observed so far, to the best of our knowledg

Stable nanovesicles formed by intrinsically planar bilayers

Quatsome nanovesicles, formed through the self-assembly of cholesterol (CHOL) and cetyltrimethylammonium bromide (CTAB) in water, have shown long-term stability in terms of size and morphology, while at the same time exhibiting high CHOL-CTAB intermolecular binding energies. We hypothesize that CHOL/CTAB quatsomes are indeed thermodynamically stable nanovesicles, and investigate the mechanism underlying their formation.This work was supported by funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement No 712949 (TECNIOspring PLUS) and from the Agency for Business Competitiveness of the Government of Catalonia. The production of quatsomes and part of their characterization has been performed by the ICTS “NANBIOSIS”, more specifically by the Biomaterial Processing and Nanostructuring Unit (U6), Unit of the CIBER in Bioengineering, Biomaterials & Nanomedicine (CIBER-BBN) located at the Institute of Materials Science of Barcelona (ICMAB-CSIC). ICMAB-CSIC acknowledges support from the MINECO through the Severo Ochoa Programme for Centres of Excellence in R&D (SEV-2015-0496 and CEX2019-000917-S). Authors acknowledge financial support from the Spanish Ministry of Science and Innovation through grants “MOL4BIO” (PID2019-105622RB-I00), “SimBioSoft” (PID2021-124297NB-C33) and the FUNFUTURE-FIP-2020 Severo Ochoa project, from Generalitat de Catalunya through grant 2017-SGR-918, from CSIC through grant 2019AEP133, and from the European Commission through the H2020 PHOENIX project (contract no. 953110). We acknowledge the support of the Israel scienceIsrael science Foundation, grant 1117/2016, and thank Dr. Inbal Ionita for her professional assistance in the cryo-TEM analysis. We thank Jannik Nedergaard Pedersen and Beatrice Plazzotta for help with the SAXS measurements. The simulations reported here were performed using the Cori Supercomputing facility of the National Energy Research Scientific Computing Center (NERSC), a U.S. Department of Energy Office of Science User Facility operated under Contract No. DE-AC02-05CH11231.With funding from the Spanish government through the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000917-S).Peer reviewe

Can We Predict the Appearance of the Most Virulent COVID-19 Outbreaks in the World?

The COVID-19 pandemic has spread throughout the world at great speed, however, its capacity for expansion and therefore its impact on a country's health system and its economy is not the same in the different areas of the world. In this work, we present a study on the influence of temperature on the speed of virus transmission. The study has been carried out with data collected in a narrow time window, one month, and from a reduced geographical area such as a single country, as Spain, or a cruise such as the Diamond Princess. The objective is to have the data as homogeneous as possible and try to minimize the influence of factors that are not strictly environmental. The result is that there is a clear relationship between the temperature and the speed of virus spread.N

Third generation dendrimer, process for production thereof and use thereof

[EN] The present invention discloses a third generation polyphosphorhydrazone (PPH) dendrimer peripherally functionalized with PROXYL radical units, by using a tyrosine amino acid (Tyr) as linker. The present invention also relates to the process of obtainment of said dendrimer and the use thereof as a magnetic resonance imaging (MRI) contrast agent[FR] La présente invention concerne un dendrimère de polyphosphorhydrazone (PPH) de troisième génération fonctionnalisé périphériquement par des unités radicalaires PROXYL, au moyen d'un acide aminé tyrosine (Tyr) en tant que lieur. La présente invention concerne également le procédé d'obtention dudit dendrimère et son utilisation en tant qu'agent de contraste pour imagerie par résonance magnétique (IRM)Peer reviewedConsejo Superior de Investigaciones Científicas (España)A1 Solicitud de patente con informe sobre el estado de la técnic