Dimensional crossover of correlated anion disorder in oxynitride perovskites

A simple crossover from two-dimensional to three-dimensional correlated disorder of O and N atoms on a cubic lattice has been discovered within the Ba1xSrxTaO2N series of perovskite oxynitrides. The crossover is driven by lattice expansion as x decreases, and provides a rapid increase in entropy due to a change from subextensive to extensive configurational entropy regimes.We thank STFC, UK for support for H. J. and provision of ISIS beamtime, and EPSRC for additional support. This work was also supported by the Ministerio de Economia y Competitividad (MINECO), Spain through Project MAT2017-86616-R, the Severo Ochoa Program SEV-2015-0496, and Fellowship support to AB (MAT2011-24757). We thank the ALBA synchrotron for the provision of beamtime and Prof. Rosa Palacin, Dr Carlos Frontera (ICMAB-CSIC) and Dr F. Fauth (ALBA) for assistance with data collection.Peer reviewe

Finishing the euchromatic sequence of the human genome

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

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

New oxynitride materials with luminescent, magnetic and catalytic properties

En les darreres dècades els oxinitrurs han rebut un interès creixent degut al vast rang d'aplicacions en els quals han mostrat una aplicabilitat potencial. Destaquen les seves propietats com fotocatalitzadors actius en el visible en processos de fotòlisi d'aigua, pigments inorgànics no tòxics, fòsfors per a LEDs (light emitting diodes) de llum blanca, materials amb magneto resistència colossal i materials dielèctrics o ferroelèctrics. En aquesta tesi presentem la síntesi i caracterització de dos nous fòsfors amb potencial aplicació en tecnologia LED de llum blanca. Els oxinitrursilicats LaSrSiO3N i LaBaSiO3N quan són activats amb Eu2+ emeten llum de color vermell ataronjat sota excitació amb radiació blava o UV. La solució sòlida Sr2-xLaxSiO4-xNx (0 ≤ x ≤ 1) es pot obtenir per la substitució concomitant de Sr2+ per La3+ i O2- per N3- en l’òxid Sr2SiO4. Mitjançant el control de la composició, es pot modificar el color de l'emissió des del grog (x = 0.2) fins a vermell ataronjat (x = 1) quan es dopa amb Eu2+ i des del blau verdós (x = 0.2) fins taronja groguenc (x = 1) quan es dopa amb Ce3+. D'altra banda, aquesta tesi també ha tingut com a objectiu la síntesi i estudi de nous oxinitrurs amb estructura de perovskita extenent el rang d’aquest grup de compostos als metall de transició Cr i Hf. Les perovskites LnCrO3-xNx amb Ln = La, Pr, Nd i continguts de nitrogen fins x = 0.59 van ser sintetitzats per mitjà de la amonòlisis dels precursors LnCrO4. La substitució d'oxigen per nitrogen indueix l'oxidació de Cr3+ a Cr4+ com a mecanisme de compensació de càrrega i les conseqüències que comporta sobre les propietats magnètiques han sigut investigades. El dopatge amb forats en les perovskites LnCrO3 produït mitjançant la substitució dels anions O2- per N3- suprimeix l'ordre magnètic però menys dràsticament que quan és induït per la substitució catiònica de Ln3+ per M2+ (M = Ca, Sr ). Finalment, presentem la síntesi, caracterització estructural i l'estudi de les propietats elèctriques i fotocatalítiques dels nous oxinitrurs amb estructura de perovskita de hafni LnHfO2N (Ln = La, Pr, Nd, Sm) i del compost anàleg LaZrO2N. Aquests materials cristal·litzen en una estructura ròmbica de tipus GdFeO3 i presenten band gaps entre 3.4 i 2.8 eV. L'evolució d'H2 i O2 produïda sota la il·luminació amb radiació d'un llum de Xenó de 300 W va demostrar que les perovsquites de hafni tenen els potencials de reducció i oxidació adequats per dur a terme dissociació de la molècula d'aigua en presència dels convenients agents de sacrifici. Les mesures de permitivitat dielèctrica i resistivitat elèctrica van mostrar que els compostos LnHfO2N (Ln = La, Pr, Nd, Sm) són aïllants elèctrics amb constants dielèctriques entre 16 i 30 a temperatura ambient.In recent years oxynitride materials have received increasing attention because of their emerging applications as photocatalysts, phosphors, pigments, dielectrics and magnetic materials. This thesis reports the synthesis and characterization of two new oxynitride phosphors with potential application in warm white light LED technologies. The new compounds LaSrSiO3N and LaBaSiO3N activated with Eu2+ are orange-red light-emitting luminescent materials under excitation in the UV-blue range. We also report that the solid solution Sr2-xLaxSiO4-xNx (0≤ x ≤1), can be obtained by concomitant substitution of Sr2+ by La3+ and O2- by N3- in Sr2SiO4. By controlling the composition the emission colours can be tuned from yellow (x = 0.2) to orange-red (x = 1) for Eu2+ phosphors and from blue-green (x = 0.2) to orange-yellow (x = 1) in Ce3+ doped samples. On the other hand, this thesis has been directed towards the synthesis and study of new oxynitride perovskites extending the range of this group of compounds to the transition metals Cr and Hf. LnCrO3-xNx perovskites with Ln = La, Pr and Nd and nitrogen contents up to x = 0.59 have been synthesised through ammonolysis of LnCrO4 precursors. Nitride substitution induces oxidation of Cr3+ to Cr4+ as the mechanism of charge compensation and the consequences of this on magnetic ordering transitions have been studied. Hole-doping through O2-/N3- anion substitution suppresses magnetic order but far less drastically than Ln3+/M2+ (M = Ca, Sr) cation substitutions. Finally, we show the synthesis, structure, electrical and photocatalytic properties of new hafnium oxynitride perovskites LnHfO2N where Ln= La, Pr, Nd and Sm, and the previously reported analogous compound LaZrO2N. They crystallize in the orthorhombic GdFeO3-type superstructure and show band gaps between 3.4 and 2.8 eV. The time course of O2 and H2 evolution under Xenon lamp 300 W irradiation showed that the hafnium perovskites have the adequate oxidation and reduction potential to conduct the overall water splitting reaction in presence of a sacrificial agent. Dielectric and resistivity measurements showed that both Hf and Zr perovskite oxynitrides are electric insulators with dielectric constants between 16 and 30 at room temperature

New oxynitride materials with luminescent, magnetic and catalytic properties /

En les darreres dècades els oxinitrurs han rebut un interès creixent degut al vast rang d'aplicacions en els quals han mostrat una aplicabilitat potencial. Destaquen les seves propietats com fotocatalitzadors actius en el visible en processos de fotòlisi d'aigua, pigments inorgànics no tòxics, fòsfors per a LEDs (light emitting diodes) de llum blanca, materials amb magneto resistència colossal i materials dielèctrics o ferroelèctrics. En aquesta tesi presentem la síntesi i caracterització de dos nous fòsfors amb potencial aplicació en tecnologia LED de llum blanca. Els oxinitrursilicats LaSrSiO3N i LaBaSiO3N quan són activats amb Eu2+ emeten llum de color vermell ataronjat sota excitació amb radiació blava o UV. La solució sòlida Sr2-xLaxSiO4-xNx (0 ≤ x ≤ 1) es pot obtenir per la substitució concomitant de Sr2+ per La3+ i O2- per N3- en l'òxid Sr2SiO4. Mitjançant el control de la composició, es pot modificar el color de l'emissió des del grog (x = 0.2) fins a vermell ataronjat (x = 1) quan es dopa amb Eu2+ i des del blau verdós (x = 0.2) fins taronja groguenc (x = 1) quan es dopa amb Ce3+. D'altra banda, aquesta tesi també ha tingut com a objectiu la síntesi i estudi de nous oxinitrurs amb estructura de perovskita extenent el rang d'aquest grup de compostos als metall de transició Cr i Hf. Les perovskites LnCrO3-xNx amb Ln = La, Pr, Nd i continguts de nitrogen fins x = 0.59 van ser sintetitzats per mitjà de la amonòlisis dels precursors LnCrO4. La substitució d'oxigen per nitrogen indueix l'oxidació de Cr3+ a Cr4+ com a mecanisme de compensació de càrrega i les conseqüències que comporta sobre les propietats magnètiques han sigut investigades. El dopatge amb forats en les perovskites LnCrO3 produït mitjançant la substitució dels anions O2- per N3- suprimeix l'ordre magnètic però menys dràsticament que quan és induït per la substitució catiònica de Ln3+ per M2+ (M = Ca, Sr ). Finalment, presentem la síntesi, caracterització estructural i l'estudi de les propietats elèctriques i fotocatalítiques dels nous oxinitrurs amb estructura de perovskita de hafni LnHfO2N (Ln = La, Pr, Nd, Sm) i del compost anàleg LaZrO2N. Aquests materials cristal·litzen en una estructura ròmbica de tipus GdFeO3 i presenten band gaps entre 3.4 i 2.8 eV. L'evolució d'H2 i O2 produïda sota la il·luminació amb radiació d'un llum de Xenó de 300 W va demostrar que les perovsquites de hafni tenen els potencials de reducció i oxidació adequats per dur a terme dissociació de la molècula d'aigua en presència dels convenients agents de sacrifici. Les mesures de permitivitat dielèctrica i resistivitat elèctrica van mostrar que els compostos LnHfO2N (Ln = La, Pr, Nd, Sm) són aïllants elèctrics amb constants dielèctriques entre 16 i 30 a temperatura ambient.In recent years oxynitride materials have received increasing attention because of their emerging applications as photocatalysts, phosphors, pigments, dielectrics and magnetic materials. This thesis reports the synthesis and characterization of two new oxynitride phosphors with potential application in warm white light LED technologies. The new compounds LaSrSiO3N and LaBaSiO3N activated with Eu2+ are orange-red light-emitting luminescent materials under excitation in the UV-blue range. We also report that the solid solution Sr2-xLaxSiO4-xNx (0≤ x ≤1), can be obtained by concomitant substitution of Sr2+ by La3+ and O2- by N3- in Sr2SiO4. By controlling the composition the emission colours can be tuned from yellow (x = 0.2) to orange-red (x = 1) for Eu2+ phosphors and from blue-green (x = 0.2) to orange-yellow (x = 1) in Ce3+ doped samples. On the other hand, this thesis has been directed towards the synthesis and study of new oxynitride perovskites extending the range of this group of compounds to the transition metals Cr and Hf. LnCrO3-xNx perovskites with Ln = La, Pr and Nd and nitrogen contents up to x = 0.59 have been synthesised through ammonolysis of LnCrO4 precursors. Nitride substitution induces oxidation of Cr3+ to Cr4+ as the mechanism of charge compensation and the consequences of this on magnetic ordering transitions have been studied. Hole-doping through O2-/N3- anion substitution suppresses magnetic order but far less drastically than Ln3+/M2+ (M = Ca, Sr) cation substitutions. Finally, we show the synthesis, structure, electrical and photocatalytic properties of new hafnium oxynitride perovskites LnHfO2N where Ln= La, Pr, Nd and Sm, and the previously reported analogous compound LaZrO2N. They crystallize in the orthorhombic GdFeO3-type superstructure and show band gaps between 3.4 and 2.8 eV. The time course of O2 and H2 evolution under Xenon lamp 300 W irradiation showed that the hafnium perovskites have the adequate oxidation and reduction potential to conduct the overall water splitting reaction in presence of a sacrificial agent. Dielectric and resistivity measurements showed that both Hf and Zr perovskite oxynitrides are electric insulators with dielectric constants between 16 and 30 at room temperature

Topochemical nitridation of Sr2FeMoO6

The topotactic nitridation of cation ordered, tetragonal SrFeMoO in NH at moderate temperatures leads to cubic, Fm3m double perovskite oxynitride SrFeMoON where double-exchange interactions determine ferromagnetic order with T ≈ 100 K. Substitution of oxide by nitride induces bond asymmetries and local electronically driven structural distortions, which combined with Fermi level lowering restricts charge itinerancy to confined regions and preclude spontaneous long-range magnetic order. Under a magnetic field, ferromagnetic correlations expand, favoring charge delocalization and a negative magnetoresistance is observed

Operando Synchrotron X-ray Diffraction in Calcium Batteries : Insights into the Redox Activity of 1D CaCoMO (M = Co and Mn)

1D CaCoMO (M = Co z = 0, M = Mn z = 1, and M = Fe z = 0.4) were prepared and tested electrochemically. While the iron-containing phase was not found to be active, the iron- and manganese-containing phases were found to be potentially interesting as positive electrode materials for calcium metal-based high-energy battery technologies and were investigated by operando synchrotron X-ray diffraction. Results indicate that electrochemically driven calcium deintercalation from the crystal structure (ca. 0.7 mol per formula unit) takes place upon oxidation in both cases. The oxidized phases have incommensurate modulated crystal structures with the space group R 3 m (00γ)0s and a = 9.127(1) Å, c = 2.4226(3) Å and c = 4.1857(3) Å, and γ = 0.579 (M = Co) and a = 9.217(1) Å, c = 4.9076(4) Å and c = 4.3387(4) Å, and γ = 1.139 (M = Mn), which exhibit differences due to the presence of manganese and Mn/Co ordering. The degree of calcium re-intercalation within the structure was found to be extremely limited, if any. Complementary experiments carried out in lithium cells did not show any reversibility either, thus pointing at intrinsic structural/migration constraints in the oxidized phase rather than slow kinetics of high desolvation energies associated with divalent ion charge carriers

Comprehensive, Integrative Genomic Analysis of Diffuse Lower-Grade Gliomas

BACKGROUND Diffuse low-grade and intermediate-grade gliomas (which together make up the lower-grade gliomas, World Health Organization grades II and III) have highly variable clinical behavior that is not adequately predicted on the basis of histologic class. Some are indolent; others quickly progress to glioblastoma. The uncertainty is compounded by interobserver variability in histologic diagnosis. Mutations in IDH, TP53, and ATRX and codeletion of chromosome arms 1p and 19q (1p/19q codeletion) have been implicated as clinically relevant markers of lower-grade gliomas. METHODS We performed genomewide analyses of 293 lower-grade gliomas from adults, incorporating exome sequence, DNA copy number, DNA methylation, messenger RNA expression, microRNA expression, and targeted protein expression. These data were integrated and tested for correlation with clinical outcomes. RESULTS Unsupervised clustering of mutations and data from RNA, DNA-copy-number, and DNA-methylation platforms uncovered concordant classification of three robust, nonoverlapping, prognostically significant subtypes of lower-grade glioma that were captured more accurately by IDH, 1p/19q, and TP53 status than by histologic class. Patients who had lower-grade gliomas with an IDH mutation and 1p/19q codeletion had the most favorable clinical outcomes. Their gliomas harbored mutations in CIC, FUBP1, NOTCH1, and the TERT promoter. Nearly all lower-grade gliomas with IDH mutations and no 1p/19q codeletion had mutations in TP53 (94%) and ATRX inactivation (86%). The large majority of lower-grade gliomas without an IDH mutation had genomic aberrations and clinical behavior strikingly similar to those found in primary glioblastoma. CONCLUSIONS The integration of genomewide data from multiple platforms delineated three molecular classes of lower-grade gliomas that were more concordant with IDH, 1p/19q, and TP53 status than with histologic class. Lower-grade gliomas with an IDH mutation either had 1p/19q codeletion or carried a TP53 mutation. Most lower-grade gliomas without an IDH mutation were molecularly and clinically similar to glioblastomaclose