22 research outputs found

    Conducting Molecular Nanomagnet of DyIII with Partially Charged TCNQ Radicals

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    artĂ­culo cientĂ­ficoBifunctional electrically conducting single-molecule magnets are highly promising platforms for non-volatile memory devices and quantum computing applications. The development of these molecular materials, however, has largely been hindered by the lack of straightforward synthetic methods. Herein we demonstrate a facile and modular approach for the realization of bifunctional materials that does not require electrochemical or chemical oxidation to obtain partially charged organic radicals. Magnetic and electrical conductivity studies reveal that the Dy(III) compound exhibits slow relaxation of the magnetization between 5.0-8.0 K and semiconducting behavior over the range 180-350 K. DC magnetic fields suppress the quantum tunneling of the magnetization and affect the spin-canted antiferromagnetic interactions.U.S. Department of Energy

    Relaxation Dynamics of Identical Trigonal Bipyramidal Cobalt Molecules with Different Local Symmetries and Packing Arrangements: Magnetostructural Correlations and ab inito Calculations

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    A family of isostructural, mononuclear CoII complexes with distorted trigonal bipyramidal coordination environments is reported. The degree of distortion as well as the overall symmetry of the molecules varies among the members of the series. Different experimental procedures resulted in the isolation of solvomorphs (pseudopolymorphs with different solvent content) for some of the family members. Importantly, their disparate packing arrangements lead to very different dynamic magnetic behavior. The results of magnetostructural correlations and ab initio calculations reveal that the deciding factor for SMM behavior is not the degree of distortion which, a priori, would be expected to be the case, but rather the interactions between neighboring molecules in the solid state.Department of Energy, Basic Energy Sciences, Materials Sciences Division Robert A. Welch Foundation for financial support Ciencia y TecnologĂ­a del Distrito Federal (ICyTDF) Spanish Ministerio de EconomĂ­a y Competitivida

    Strong Ferromagnetic Exchange Coupling Mediated by a Bridging Tetrazine Radical in a Dinuclear Nickel Complex.

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    The radical bridged compound [(Ni- (TPMA))2-ÎŒ-bmtz‱−](BF4)3·3CH3CN (bmtz = 3,6-bis- (2â€Č-pyrimidyl)-1,2,4,5-tetrazine, TPMA = tris(2- pyridylmethyl)amine) exhibits strong ferromagnetic exchange between the S = 1 NiII centers and the bridging S = 1/2 bmtz radical with J = 96 ± 5 cm−1 (−2JNi‑radSNiSrad). DFT calculations support the existence of strong ferromagnetic exchange.Department of Energy Office of Science Graduate Fellowship, Instituto de Ciencia y Tecnología del Distrito Federal (ICyTDF) National Science Foundation (CHE-1310574) and the Robert A. Welch Foundation (A-1449)

    Proceedings of Patient Reported Outcome Measure’s (PROMs) Conference Oxford 2017: Advances in Patient Reported Outcomes Research

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    A33-Effects of Out-of-Pocket (OOP) Payments and Financial Distress on Quality of Life (QoL) of People with Parkinson’s (PwP) and their Carer

    Long-term thermal sensitivity of Earth’s tropical forests

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    The sensitivity of tropical forest carbon to climate is a key uncertainty in predicting global climate change. Although short-term drying and warming are known to affect forests, it is unknown if such effects translate into long-term responses. Here, we analyze 590 permanent plots measured across the tropics to derive the equilibrium climate controls on forest carbon. Maximum temperature is the most important predictor of aboveground biomass (−9.1 megagrams of carbon per hectare per degree Celsius), primarily by reducing woody productivity, and has a greater impact per °C in the hottest forests (>32.2°C). Our results nevertheless reveal greater thermal resilience than observations of short-term variation imply. To realize the long-term climate adaptation potential of tropical forests requires both protecting them and stabilizing Earth’s climate

    Finishing the euchromatic sequence of the human genome

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    The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∌99% of the euchromatic genome and is accurate to an error rate of ∌1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

    Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

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    IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

    Strong Direct Magnetic Coupling in a Dinuclear CoII Tetrazine Radical Single-Molecule Magnet.

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    artĂ­culo cientĂ­ficoThe ligand-centered radical complex [(CoTPMA)2-ÎŒ-bmtz.−](O3SCF3)3⋅CH3CN (bmtz=3,6-bis(2â€Č-pyrimidyl)-1,2,4,5-tetrazine, TPMA=tris-(2-pyridylmethyl)amine) has been synthesized from the neutral bmtz precursor. Single-crystal X-ray diffraction studies have confirmed the presence of the ligand-centered radical. The CoII complex exhibits slow paramagnetic relaxation in an applied DC field with a barrier to spin reversal of 39 K. This behavior is a result of strong antiferromagnetic metal–radical coupling combined with positive axial and strong rhombic anisotropic contributions from the CoII ions.National Science Foundation Ciencia y Tecnolog a del Distrito Federal (ICyTDF) STC
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