Magnetic structure and spin dynamics of quasi-one-dimensional spin-chain antiferromagnet BaCo2V2O8

We report a neutron diffraction and muon spin relaxation muSR study of static and dynamical magnetic properties of BaCo2V2O8, a quasi-one-dimensional spin-chain system. A proposed model for the antiferromagnetic structure includes: a propagation vector k_AF = (0, 0, 1), independent of external magnetic fields for fields below a critical value H_c(T). The ordered moments, of 2.18 \mu_B per Co ion, are aligned along the crystallographic c-axis. Within the screw chains, along the c axis, the moments are arranged antiferromagnetically. In the basal planes the spins are arranged ferromagnetically (forming zig-zags paths) along one of the axis and antiferromagnetically along the other. The temperature dependence of the sub-lattice magnetization is consistent with the expectations of the 3D Ising model. A similar behavior is observed for the internal static fields at different muon stopping sites. Muon time spectra measured at weak longitudinal fields and temperatures much higher than T_N can be well described using a single muon site with an exponential muon spin relaxation that gradually changes into an stretched exponential on approaching T_N. The temperature-induced changes of the relaxation suggest that the Co fluctuations dramatically slow down and the system becomes less homogeneous as it approaches the antiferromagnetic state.Comment: 7 pages, 9 figure

Surfactant-free solution synthesis of fluorescent platinum subnanoclusters

We have demonstrated the first surfactant-free synthesis of fluorescent Pt nanoclusters in N,N-dimethylformamide (DMF) solution. The Pt nanoclusters consist of 4 to 6 Pt atoms. They form highly stable dispersions in water, under both acidic (pH 2) and basic conditions (pH 12), and at ionic strengths of 1 M NaCl

Omecamtiv mecarbil in chronic heart failure with reduced ejection fraction, GALACTIC‐HF: baseline characteristics and comparison with contemporary clinical trials

Aims: The safety and efficacy of the novel selective cardiac myosin activator, omecamtiv mecarbil, in patients with heart failure with reduced ejection fraction (HFrEF) is tested in the Global Approach to Lowering Adverse Cardiac outcomes Through Improving Contractility in Heart Failure (GALACTIC‐HF) trial. Here we describe the baseline characteristics of participants in GALACTIC‐HF and how these compare with other contemporary trials. Methods and Results: Adults with established HFrEF, New York Heart Association functional class (NYHA) ≥ II, EF ≤35%, elevated natriuretic peptides and either current hospitalization for HF or history of hospitalization/ emergency department visit for HF within a year were randomized to either placebo or omecamtiv mecarbil (pharmacokinetic‐guided dosing: 25, 37.5 or 50 mg bid). 8256 patients [male (79%), non‐white (22%), mean age 65 years] were enrolled with a mean EF 27%, ischemic etiology in 54%, NYHA II 53% and III/IV 47%, and median NT‐proBNP 1971 pg/mL. HF therapies at baseline were among the most effectively employed in contemporary HF trials. GALACTIC‐HF randomized patients representative of recent HF registries and trials with substantial numbers of patients also having characteristics understudied in previous trials including more from North America (n = 1386), enrolled as inpatients (n = 2084), systolic blood pressure < 100 mmHg (n = 1127), estimated glomerular filtration rate < 30 mL/min/1.73 m2 (n = 528), and treated with sacubitril‐valsartan at baseline (n = 1594). Conclusions: GALACTIC‐HF enrolled a well‐treated, high‐risk population from both inpatient and outpatient settings, which will provide a definitive evaluation of the efficacy and safety of this novel therapy, as well as informing its potential future implementation

Some Considerations of on Repolarization Process of vebtricular Muscle, Represented by the T Wave in the ECG

The electrogram of the frog' s ventricle was recorded with various methods, and the relationship between the repolariztion process in the muscle cell and the ''upright'' T wave in the usual electrocardiogram was discussed. 1). The extracellulary recorded potential has a derivative form of the intracellular action potential, and the positively directed potential is the result for the repolarization phase. 2). The concept of ventricular gradient seems valid for the explanation of the upright T wave. But the relative region in this concept need not be so far as described by others. 3). The rate of repolarization was also one of the important factor in the discussion

Inter- and Intraspecific Patterns in Resprouting of Trees in Undisturbed Natural Forests along an Elevational Gradient in Central Japan

Resprouting is an important functional trait for determining community dynamics and the persistence of individuals and populations. However, community-wide research on resprouting has primarily focused on severely damaged trees. We investigated resprouting from trees in a range of undisturbed natural forests along an elevational gradient in central Japan and analyzed the data at inter- and intraspecific levels. First, we formulated interspecific relationships among resprout production, parent stem growth, multi-stemmedness, and dominance in forest communities using a structural equation model (SEM). Second, we analyzed intraspecific variation in the resprout number per stem for nine resprouting species using a hierarchical Bayesian method. We found that resprout production and parent stem growth were negatively correlated; resprouting resulted in multi-stemmed adult forms, and species with multi-stemmed forms tended to be less dominant in undisturbed forest communities. We observed various intraspecific resprouting responses to parental and environmental factors. For example, soil temperature had generally positive effects for most species, whereas dbh appeared to have only weak effects on a few species. Our SEM summarized well the direct and indirect relationships of species’ traits, including resprout production, in the undisturbed forests. The observed intraspecific patterns in the resprouting responses can serve as a starting point for understanding species’ traits within this context