Deformation of the triangular spin-12 lattice in Na2SrCo(PO4)2

Crystal structure and thermodynamic properties of Na2SrCo(PO4)2, the chemical sibling of the triangular quantum spin-liquid candidate Na2BaCo(PO4)2, are reported. From single crystal x-ray diffraction and high-resolution synchrotron x-ray powder diffraction, the compound was found to crystallize in the monoclinic space group P21/a at room temperature, in contrast to the trigonal Na2BaCo(PO4)2. Above 650 K, the symmetry of Na2SrCo(PO4)2 changes to C2/m, while around 1025 K a further transformation toward trigonal symmetry is observed. The monoclinic symmetry leads to a small deformation of the CoO6 octahedra beyond the trigonal distortion ubiquitous in this structure type and results in the stronger g-tensor anisotropy (gz/gxy=1.6) as well as the increased XXZ anisotropy (Jz/Jxy=2.1) compared to the Ba compound (gz/gxy=1.1, Jz/Jxy=1.5), while the average coupling strength, Jav/kB=(2Jxy+Jz)/3kB≃1.3K, remains unchanged. The Néel temperature increases from 140 mK (Ba) to 600 mK (Sr), and an uncompensated in-plane moment of 0.066(4)μB/f.u. appears. We show that the ordering temperature of a triangular antiferromagnet is capably controlled by its structural distortions

Geometrical frustration and incommensurate magnetic order in Na3RuO4 with two triangular motifs

Incommensurate magnetic order in the spin-3/2 antiferromagnet Na3RuO4 is uncovered by neutron diffraction combined with ab initio calculations. The crystal structure of Na3RuO4 contains two triangular motifs on different length scales. The magnetic Ru5+ ions form a lozenge (diamond) configuration, with tetramers composed of two isosceles triangles. These tetramers are further arranged in layers, such that an effective triangular lattice is formed. The tetramers are nearly antiferromagnetic but frustration between them leads to an incommensurately modulated magnetic structure described by the propagation vector →k=(0.242(1),0,0.313(1)). We show that the long-range Ru-O-O-Ru couplings between the tetramers play a major role in Na3RuO4 and suggest an effective description in terms of the spatially anisotropic triangular lattice if the tetramers are treated as single sites

Genetic association study of QT interval highlights role for calcium signaling pathways in myocardial repolarization.

The QT interval, an electrocardiographic measure reflecting myocardial repolarization, is a heritable trait. QT prolongation is a risk factor for ventricular arrhythmias and sudden cardiac death (SCD) and could indicate the presence of the potentially lethal mendelian long-QT syndrome (LQTS). Using a genome-wide association and replication study in up to 100,000 individuals, we identified 35 common variant loci associated with QT interval that collectively explain ∼8-10% of QT-interval variation and highlight the importance of calcium regulation in myocardial repolarization. Rare variant analysis of 6 new QT interval-associated loci in 298 unrelated probands with LQTS identified coding variants not found in controls but of uncertain causality and therefore requiring validation. Several newly identified loci encode proteins that physically interact with other recognized repolarization proteins. Our integration of common variant association, expression and orthogonal protein-protein interaction screens provides new insights into cardiac electrophysiology and identifies new candidate genes for ventricular arrhythmias, LQTS and SCD

A922 Sequential measurement of 1 hour creatinine clearance (1-CRCL) in critically ill patients at risk of acute kidney injury (AKI)

Meeting abstrac

Nurses' perceptions of aids and obstacles to the provision of optimal end of life care in ICU

Contains fulltext : 172380.pdf (publisher's version ) (Open Access

Retrospective evaluation of whole exome and genome mutation calls in 746 cancer samples

Funder: NCI U24CA211006Abstract: The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) curated consensus somatic mutation calls using whole exome sequencing (WES) and whole genome sequencing (WGS), respectively. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, which aggregated whole genome sequencing data from 2,658 cancers across 38 tumour types, we compare WES and WGS side-by-side from 746 TCGA samples, finding that ~80% of mutations overlap in covered exonic regions. We estimate that low variant allele fraction (VAF < 15%) and clonal heterogeneity contribute up to 68% of private WGS mutations and 71% of private WES mutations. We observe that ~30% of private WGS mutations trace to mutations identified by a single variant caller in WES consensus efforts. WGS captures both ~50% more variation in exonic regions and un-observed mutations in loci with variable GC-content. Together, our analysis highlights technological divergences between two reproducible somatic variant detection efforts

Comparative effects of the dual metallopeptidase inhibitor, MDL 100,240 and of enalaprilat on regional and on cardiac haemodynamics in conscious, hypertensive, transgenic ((mRen-2)27) rats

1. Heterozygous, male, hypertensive, transgenic ((mRen-2)27) rats (350–450 g) were instrumented for the measurement of regional or cardiac haemodynamics (n = 16, in both groups). Animals were given continuous i.v. infusions of the angiotensin-converting enzyme inhibitor, enalaprilat, or the dual metallopeptidase inhibitor, MDL 100,240 (both at 3 mg kg(−1), 3 mg kg(−1) h(−1); n = 8 for regional and cardiac haemodynamics), for 32 h. Twenty four hours after the onset of infusion of enalaprilat or MDL 100,240, the bradykinin (B(2))-receptor antagonist, Hoe 140 (1 mg kg(−1), i.v.), was given and measurements were continued for a further 8 h, to assess any possible involvement of bradykinin. 2. Over the first 8 h of infusion, both enalaprilat and MDL 100,240 had significant antihypertensive effects, accompanied by similar regional vasodilatations. However, the blood pressure lowering effect of MDL 100,240 (−54 ± 9 mmHg) was greater than that of enalaprilat (−38 ± 4 mmHg), because the former caused a significantly greater reduction in cardiac index. 3. Between 8–24 h after the onset of infusion, there was a reduction in the effect of enalaprilat on blood pressure, because cardiac index rose, with no further increase in total peripheral conductance. In contrast, the antihypertensive effect of MDL 100,240 persisted, in spite of a recovery in cardiac index, because there was further vasodilatation, particularly in the mesenteric and hindquarters vascular beds. 4. There were no apparent haemodynamic changes associated with the injection of Hoe 140, and over the following 8 h, the difference between the haemodynamic effects of enalaprilat and MDL 100,240 persisted; there was little evidence of suppression of the effects of either drug. 5. These results are more consistent with the antihypertensive effects of enalaprilat or MDL 100,240 in transgenic ((mRen-2)27) rats being due to suppression of angiotensin II production, than due to inhibition of bradykinin degradation. The additional effects of MDL 100,240 may be accounted for by inhibition of the degradation of natriuretic peptides reducing cardiac output, initially, and decreasing vascular tone, subsequently. Alternatively, the additional increase in vascular conductance following treatment with MDL 100,240 may represent an autoregulatory response to the reduced pressure