Search

The prospective Control of HEART rate in inFant and child tachyarrhythmia with reduced cardiac function Using Landiolol (HEARTFUL) study investigated the effectiveness and safety of landiolol, a short-acting βThe HEARTFUL study has demonstrated the efficacy of landiolol, by reducing heart rate or terminating tachycardia, in pediatric patients with supraventricular tachyarrhythmias. Although serious ARs and concerns were not identified in this study, physicians should be always cautious of circulatory collapse due to hypotension.

Two cases of focal atrial tachycardia probably originating from the pulmonary vein with onset later than 3 years of age are presented. Both cases had associated variable atrioventricular conduction and showed no signs of heart failure, and they converted to sinus rhythm at the time of puberty. In cases of focal atrial tachycardia originating from the pulmonary vein with onset later than 3 years of age, drug therapy may be effective. Even if drug therapy is not effective, changes in the autonomic nervous system are reflected strongly in the pulmonary veins, so that changes in autonomic nervous system regulation with growth might terminate focal atrial tachycardia. Therefore, focal atrial tachycardia originating from the pulmonary vein with onset later than 3 years of age might have a better prognosis.

International audience; We report the reentrant phase transition of the organic-inorganic hybrid metal cluster (MC) compound (TBA)(2)[(Mo6Br8Br6a)-Br-i] (TBA = ((n-C4H9)(4)N)). Structural studies revealed that (TBA)(2)[(Mo6Br8Br6a)-Br-i] was crystallized in the conventional monoclinic phase with space group P2(1)/n. When the crystal was cooled down to 143 K, we observed a structural phase transition from the conventional phase to an unknown phase with packing structure similar to the conventional one; however, the unit cell was extended to a double size. A reentrant transition to the conventional structure was induced when the crystal was further cooled to 113 K. These reentrant phase transitions occurred without any symmetry changes caused by slight motions of the MCs and TBA(+) ions. Luminescence studies revealed that the phase transition poorly affected the emission spectra; however, the newly found phase exhibited 1.7 times longer emission lifetime than the conventional phase. These results indicate that MC-based compounds are promising and exhibit phase transitions and crystallographic polymorphisms.

We presented a new hybrid lead chloride–DMSO solvate, FAPbCl3–DMSO, and explained the crystallization of this solvate in DMSO by the formation enthalpy calculation.

Zn3N2 (ZN) and ZnSnN2 (ZTN) are a promising class of nitride semiconductors for photovoltaic and light-emitting-diode applications due to their particular electrical and optical properties, elemental abundance and non-toxicity. So far, most of the experimental results show the degenerate carrier concentration. However, we find that low-temperature growth of these films in a chamber with ultra-high background vacuum can attain a non-degenerate electrical conductivity. This work provides the recent progress of the electrical properties of ZN and ZTN semiconductor thin films. The origins for the high carrier concentrations in ZN and ZTN have been discussed, demonstrating that non-intentional oxygen and hydrogen-related defects play significant roles in such high carrier concentrations. The strategies to suppress the carrier concentrations have also been addressed, such as ultra-high vacuum conditions and low temperature growth.

International audience; This short communication reports on the facile and scalable synthesis and characterization of molybdenum carbides/carbon nanocomposites prepared by laser pyrolysis in a one-step process. Water and commercial molybdenum oxide were used as low-cost environmentally friendly precursors. The nanocomposites are mainly composed of two types of carbides with different apparent crystallite sizes, 21 ± 1 nm and 9 ± 1 nm for Mo2C and MoC1−x, respectively. Thanks to a simple annealing at 500 °C under argon, it was possible to increase the specific surface area around 50 m2/g without changing the morphology of the nanocomposite.

International audience; The antagonism between global energy needs and the obligation to slow global warming is a current challenge. In order to ensure sufficient thermal comfort, the automotive, housing and agricultural building sectors are major energy consumers. Solar control materials and more particularly, selective glazing are part of the solutions proposed to reduce global energy consumption and tackle global warming. In this context, these works are focused on developing new highly ultraviolet (UV) and near-infrared (NIR) absorbent nanocomposite coatings based on K(4)[{Nb(6-x)Ta(x)X(i)(12)}X(a)(6)]. (X = Cl, Br, 0 ≤ x ≤ 6) transition metal cluster compounds. These compounds contain cluster-based active species that are characterized by their strong absorption of UV and NIR radiations as well as their good transparency in the visible range, which makes them particularly attractive for window applications. Their integration, by solution processes, into a silica-polyethylene glycol or polyvinylpyrrolidone matrices is discussed. Of particular interest is the control and the tuning of their optical properties during the integration and shaping processes. The properties of the solutions and films were investigated by complementary techniques (UV-Vis-NIR spectrometry, ESI-MS, SEM, HRTEM, etc.). Results of these works have led to the development of versatile solar control coatings whose optical properties are competitive with commercialized material.

International audience; Recrystallization of Cs-2[Mo6X14] (X=Cl, Br) was examined using typical organic solvents, i. e., methanol (CH3OH), acetone (CH3COCH3) and dichloromethane (CH2Cl2) in order to modify crystal structures and optoelectronic properties by promoting purity or inducing insertion of guest molecules. To this context, we performed recrystallization in solvent liquid and exposure of Cs-2[Mo6X14] to vapor of those solvents. Subsequent single crystal X-ray diffraction analyses revealed that three new types of compounds which contain high concentration of guest organic solvent molecules were obtained. Indeed, the newly found structures are Cs-2[Mo6Cl14] . 3CH(3)OH and Cs-2[Mo6X14] . 6CH(3)COCH(3) belonging to triclinic P1? space group, and Cs-2[Mo6X14] . 4CH(2)Cl(2) belonging to tetragonal P4/mnc space group. Although breaking of centrosymmetry by insertion of the guest molecule is interesting in terms of optoelectronic properties, all those new compounds belong to centrosymmetric space groups. As DFT calculations for those new compounds show that the guest molecules, such as CH3OH, do not affect the atomic arrangements and electronic features of the [Mo6X14](2-) cluster based unit, they incorporated with the lattice while keeping with the electrostatic interaction between the [Mo6X14](2-) and Cs+ ions regardless of the very high concentration of the guest solvent molecules.

We have synthesized inverse-perovskite-type oxysilicides and oxygermanides represented by R3SiO and R3GeO (R = Ca and Sr) and studied their characteristics in the search for nontoxic narrow band gap semiconductors. These compounds exhibit a sharp absorption edge around 0.9 eV and a luminescence peak in the same energy range. These results indicate that the obtained materials have a direct-band electronic structure, which was confirmed by hybrid DFT calculations. These materials, made from earth abundant and nontoxic elements and with a relatively light electron/hole effective mass, represent strong candidates for nontoxic optoelectronic devices in the infrared range.

The aim of this study is to evaluate the usefulness of T cell receptor excision circle (TREC) and/or kappa-deleting recombination excision circle (KREC) measurements integrated with diagnostic next-generation sequencing (NGS) analysis using a severe combined immunodeficiency (SCID) newborn screening (NBS) program.TREC and/or KREC values were measured in 137,484 newborns between April 2017 and December 2021 using EnLite TREC (n = 80,791) or TREC/KREC kits (n = 56,693). For newborns with positive screening results, diagnostic NGS analysis was performed with a 349-gene panel to detect genetic mutations associated with primary immunodeficiencies (PIDs).A total of 145 newborns (0.11%) had abnormal TREC and/or KREC values, and a genetic diagnosis was established in 2 patients with SCID (1 in 68,742 newborns) (IL2RG-SCID and reticular dysgenesis) and 10 with non-SCID PIDs with T and/or B cell deficiencies (1 in 13,748 newborns) using NGS analysis. Furthermore, TREC values of 2849 newborns were measured and confirmed the significant correlation between the results of both TREC and TREC/KREC kits (P 0.001) and naïve T cell counts.We performed the first large-scale TREC and TREC/KREC NBS programs in Japan. Our NBS programs followed by the diagnostic NGS analysis for newborns with abnormal TREC and/or KREC values are useful for the early identification and rapid molecular evaluation of not only SCID but also different non-SCID PIDs.

We developed a new environment-sensing device based on the opto-ionic-electronic phenomena of an octahedral molybdenum metal (Mo6) cluster. When the Mo6 cluster is electrochemically deposited on a transparent electrode in an organic solvent containing a trace amount of water, the water permeates the deposited film. During the process, some ligand species that stabilize the frame structure of the Mo6 cluster are substituted with hydroxyl groups, and the negatively charged frame structure of the Mo6 cluster unit is stabilized by hydronium counterions. As a result, the transparent film of the Mo6 cluster fabricated by this method exhibits ionic-electronic mixed conduction of the hydronium ion. The ionic conduction greatly changes depending on the temperature and humidity in the atmosphere, and the electrical conductivity greatly changes depending on the wavelength and intensity of the irradiated light. These unique multisensing properties present new possibilities for environmental sensing applications.

We report the growth of large Cl-doped and Br-doped SnS single crystals from a molten Sn-based flux. Compared with the small and lamellar undoped SnS crystals, the addition of SnCl2 or SnBr2 haloge...

A series of xBaO–yB2O3–zBi2O3 (x + y + z = 100, mol%) glasses were synthesized and added to BaTiO3 ceramics as a sintering aid to reduce the sintering temperature. The thermal and dielectric properties of the glasses and glass structures were characterized. Glasses with a high △T (difference between crystallization start temperature and glass-transition temperature) were the focus of this work. Composites with 70-mass% BaTiO3 and 30-mass% glasses and composites with high relative density and excellent dielectric properties were obtained after sintering at 600 °C. Secondary phases were formed in most of the composites; three glasses with a high △T value were formed without a secondary phase at 800 °C. Raman analysis showed that the glasses with a high △T contained Bi–O–Bi and B–O–B networks, which likely influence the thermal stability of the glasses, resulting in glasses suitable for sintering aids for BaTiO3 powders.

We investigated the multiscale characters of the crystal structure of the oxynitride perovskite LaTiO2N. While X-ray diffraction results identified the average structure as being centrosymmetric, we detected a signature of unknown structural deformation. By viewing the local structure, we unveiled the formation of a polar structure at the nanoscale.

Ferroelectric materials are defined as the materials, of which spontaneous polarization can be switched by an external electric field. Their crystal structural symmetry makes them exhibit a variety of electric properties, such as piezoelectricity, pyroelectricity, and ferroelectricity. Because of their characteristics, they are expected to be adapted for various applications, including sensors, actuators, and non-volatile memories. Over the past decades, perovskite type ferroelectric materials have occupied the central position in both fundamental studies and applications of ferroelectric materials. On the other hand, there are a few studies on ferroelectrics with other crystal structures. This regime is now changing since HfO2-based new ferroelectric materials have been discovered. The HfO2-based dielectric materials are employed as high-k insulators of the metal-oxide-semiconductor field-effect-transistors instead of the conventional SiOx gate dielectrics, suggesting the high compatibility with semiconductor technologies. Thus, discovering ferroelectricity in HfO2-based materials strongly encourages us to develop highly integrated ferroelectric devices that are difficult to fabricate with traditional perovskite-type ferroelectrics. Amid increasing interest in ferroelectric materials, ferroelectricity is demonstrated on another new (Al, Sc)N, which has a wurtzite structure. Both fluorite structure, the parent structure of HfO2-based ferroelectrics, and wurtzite structure are simple compounds, having only a single anion and cation sites in the crystal structure. This feature contrasts the complex crystal structure of conventional perovskite structure. This presentation will give a brief outline of these new ferroelectric materials and introduce our recent studies from the viewpoint of crystal chemistry. It is well-known that HfO2 undergoes successive phase transitions from monoclinic to tetragonal and tetragonal to cubic phases. However, these phases cannot show ferroelectricity because of their inversion center in the crystal structure. It is widely accepted that the ferroelectricity in HfO2-based materials originates from the metastable orthorhombic structure. This orthorhombic structure was confirmed by the convergence electron diffraction and scanning transmission electron microscopy. Among the HfO2-based materials, HfO2- ZrO2 materials are most extensively studied. However, the thickness that can exhibit ferroelectricity in these materials is limited to less than 50 nm because of their strong preference for the monoclinic structure. In order to investigate structural features of the HfO2-based materials, materials are demanded that have ferroelectricity over the wide thickness range. The Y-doped HfO2 meets the requirement, allowing us to grow the ferroelectric film over 1 μm in thickness. Furthermore, we demonstrated ferroelectricity in epitaxial films using this composition. A recent report on ferroelectricity in bulk single-crystal also employed the Y-doped HfO2 system. The ferroelectricity in the wurtzite structure has been discussed for a long time. Moriwake et al. put forward giant spontaneous polarization in wurtzite materials by calculation based on density functional theory. The proposed mechanism of polarization reversal is accompanied by the change in the outermost surface, namely a cation surface to an anion surface and vice versa. Such large polarization was demonstrated in (Al1-x Scx)N films by Fitchtner et al. They also confirmed the change in the surface by performing chemical etching. In addition to (Al1-x Scx)N films, the ferroelectricity has been confirmed in (Al1-x B x )N, (Ga1-x Sc x )N, and (Zn1-x Mg x )O. For the wurtzite structure, we can consider the virtual paraelectric BN phase, in which both anions and cations are located in the same plane. As the paraelectric phase is deemed an intermediate state during polarization reversal, easy polarization reversal is expected as the u-parameter of the wurtzite structure approaches 0.5. It is considered that the u parameter is closely related to the axial ratio of the c- and a-axes. In fact, the reduction of coercive field and remanent polarization is ascertained experimentally. The “simple compound” ferroelectrics have attracted much attention due to their unique features, e.g., outstanding compatibility to semiconductor technologies in HfO2-based materials and giant remanent polarization in wurtzite materials. However, quite a large coercive field compared to conventional ferroelectrics reduces the reliability of the devices, particularly endurance properties. Further studies and developments to unveil microstructures under and after applying a strong electric field will lead to the next application of these ferroelectrics.

In this study, high purity n-type Mg2Ge single crystals are grown in graphite crucibles under nitrogen atmosphere using a facile growth process. X-ray diffraction proves that the grown crystal consists of only Mg2Ge single phase without any other additional impurity peaks. The clear symmetrical Laue diffraction pattern of the cleaved substrate demonstrates the single crystalline nature of the grown Mg2Ge crystal ingot. The Hall Effect measurement of the polished Mg2Ge wafer shows that the latter had a moderate carrier density (5.66 * 1016 cm−3), mobility (253 cm2/V) and electrical resistivity (0.5 Ω. cm) at room temperature. Detailed analysis of the temperature dependence of the carrier density demonstrates that the shallow donor level, which gives rise to the n-type conduction of grown Mg2Ge crystals is due to the unintentional Al impurities from Mg source material. Mg2Ge pn-junction photodiodes are also manufactured for the first time by thermal diffusion of silver thin layer into n-Mg2Ge at 550 °C for 5 min in an argon atmosphere. The results reveal that the fabricated p-n photodiodes had a clear rectifying behavior and a remarkable spectral response in the wavelength range from 0.8 to 1.7 μm with a maximum room temperature zero-biased photoresponse of 7 mA/W at 1.2 μm. These outcomes indicate that the fabricated Mg2Ge photodiodes are promising to detect short-wavelength infrared (SWIR) light in the above-mentioned wavelength domain.

N-type Mg2Si single crystal ingot has been successfully grown by the Vertical Bridgman technique. The Hall Effect measurement at RT revealed a moderate Hall mobility (~ 446 cm2/Vs), electrical resistivity (~ 1.4 Ω. cm) and carrier density (~1016 cm−3) for the grown crystal. The J-V characteristics of the fabricated Au/n-Mg2Si Schottky junction and Au/Ag-doped-p-type-Mg2Si/n-type-Mg2Si/Ag pn-junction diode showed better diode behavior with higher rectifying ratio in comparison with the same reported junctions. Analysis of the experimental forward J-V characteristics of our fabricated diodes based on the thermionic emission (TE) model demonstrated that our Schottky and pn-junction Mg2Si diode exhibited much lower series resistance in comparison with the survey data, confirming that precise polishing of Mg2Si surfaces with an oil-based diamond greatly improved the contact with the evaporated metal, enabling lower interfacial resistance between the evaporated metal and Mg2Si wafer. In addition, the manufactured Mg2Si pn-junction photodiode showed a clear photoresponsivity in the wavelength range from 0.95 to 1.8 µm with a maximum zero-biased photoresponse of 14 mA/W at 1.4 µm and a photon energy threshold of approximately 0.66 eV. These results indicate that our diode is promising to detect the SWIR light in the wavelength range from 0.95 to 1.8 µm.

A 13-year-old girl had a history of episodic palpitations lasting for approximately 5 min since the first grade of junior high school. She was noticed to have tachycardia during auscultation at a school-based health screening program. Since non-sustained ventricular tachycardia of the left bundle branch block type was induced by a triple master exercise load at a local doctor’s clinic, she was referred to our pediatric cardiology department for further management. Tachycardia could not be induced by programmed stimulation in an electrophysiological study, although ventricular tachycardia was induced by atrial high frequency pacing with intravenous injection of atropine under continuous isoproterenol infusion.