Terahertz radiation by ultrafast spontaneous polarization modulation in multiferroic BiFeO3_3 thin films

Terahertz (THz) radiation has been observed from multiferroic BiFeO$_3$ thin films via ultrafast modulation of spontaneous polarization upon carrier excitation with illumination of femtosecond laser pulses. The radiated THz pulses from BiFeO$_3$ thin films were clarified to directly reflect the spontaneous polarization state, giving rise to a memory effect in a unique style and enabling THz radiation even at zero-bias electric field. On the basis of our findings, we demonstrate potential approaches to ferroelectric nonvolatile random access memory with nondestructive readability and ferroelectric domain imaging microscopy using THz radiation as a sensitive probe.Comment: 4 pages, 4 figures, submitted to Physical Review Letter

Spectroscopic evidence for a charge-density-wave condensate in a charge-ordered manganite: Observation of collective excitation mode in Pr0.7_{\text{0.7}}Ca0.3_{\text{0.3}}MnO3_{\text{3}} by using THz time-domain spectroscopy

THz time-domain spectroscopy was used to directly probe the low-energy (0.5--5 meV) electrodynamics of the charge-ordered manganite Pr$_{0.7}$Ca$_{0.3}$MnO$_3$. We revealed the existence of a finite peak structure around 2--3 meV well below the charge gap $\sim300$ meV. In analogy to the low-energy optical properties of the well-studied low-dimensional materials, we attributed this observed structure to the collective excitation mode arising from the charge-density-wave condensate. This finding provides the importance role of the quasi-one dimensional nature of the charge and orbital ordering in Pr$_{0.7}$Ca$_{0.3}$MnO$_3$.Comment: REVTeX4, 8 pages including 7 figures and 2 table

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

Menkes disease, an inborn error of copper metabolism : pathogenetic mechanism and therapeutic strategy

国立情報学研究所の「学術雑誌公開支援事業」により電子化されました

Mouth and genital ulcers with inflamed cartilage syndrome: Case report and review of the published work

Mouth and genital ulcers with inflamed cartilage (MAGIC) syndrome are disease that fulfilled criteria for diagnosis of Behcet's disease (BD) and relapsing polychondritis (RP). We report a 22-year-old Japanese woman presented with MAGIC syndrome and we described the clinicopathological characteristics of MAGIC syndrome based on a review of published cases from July 1985 to December 2015. In our case, the patient with oral aphthae, erythema nodosum, acne-like eruptions, uveitis, and polyarthritis fulfilled criteria for diagnosis of incomplete form of BD. The patient with uveitis, polyarthritis, and histological confirmation of chondritis also fulfilled criteria for diagnosis of RP. The patient was successfully treated with oral colchicine followed by prednisolone. The symptoms of MAGIC syndrome gradually disappeared, and the prednisolone dosage was gradually decreased and stopped. She has been in remission without active medication for a further 8 months. In the previous reports, some authors suggested that MAGIC syndrome was not a disease entity and might be RP occurring secondary to BD, another association of an autoimmune disease, or vasculitis with RP. However, the pathogenic association between MAGIC syndrome, BD, and RP is still unclear, and the number of reported cases of MAGIC syndrome is insufficient to establish a clear explanation. Therefore, further accumulation of data and careful observation of the clinical course are required to improve the understanding of MAGIC syndrome

Terahertz Radiation Imaging of Ferroelectric Domain Topography in Room-Temperature Hydrogen-Bonded Supramolecular Ferroelectrics

We report quasi-three-dimensional imaging of the ferroelectric domains in a hydrogen-bonded supramolecular ferroelectric 1:1 salt of 5,5′-dimethyl-2,2′-bipyridine and deuterated iodanilic acid by mapping out terahertz waves radiated from the crystal upon femtosecond laser irradiation. Polarization dependence of the effective depth radiating the terahertz waves due to the absorption anisotropy for terahertz waves allows us to distinguish domains in the inside and surface regions of the crystals. In an as-grown crystal, a large domain covering almost all the area is discerned in the inside region, while multidomains are discerned in the surface regions. We observed polarization switching via domain boundary motion in the direction perpendicular to the direction of hydrogen-bonded chains in the surface regions under an external electric field. Obtained images suggest that an uncharged 180° domain wall (DW) parallel to the stacking plane of hydrogen-bonded chains covers the whole area at coercive fields. We argue that the DW dynamics stems from the anisotropic crystal structure, i.e., stacking of hydrogen-bonded chains