-
K-T Ko,
Kyoo Kim,
Sung Baek Kim,
H-D Kim,
J-Y Kim,
B I Min,
J-H Park,
F-H Chang,
H-J Lin, A Tanaka,
S-W Cheong
[show abstract]
[hide abstract]
ABSTRACT: We investigated the magnetic nature of Fe(1/4)TaS2 using x-ray absorption spectroscopy, photoemission spectroscopy, and first principles band calculations. The results show a large unquenched orbital magnetic moment (∼1.0 μ(B)/Fe) at intercalated Fe sites, resulting in a gigantic magnetic anisotropy (H(A)≃60 T). The magnetic coupling is well understood in terms of the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction, suggesting a novel RKKY ferromagnet with Ising-type spin states. We also found that this indirect exchange coupling between the neighboring Fe spins is ferromagnetic and maximized at the Fe-Fe distance of 2×2 superstructure.
Physical Review Letters 12/2011; 107(24):247201. · 7.37 Impact Factor
-
Y Shiraishi,
T K Sugai, A Tanaka,
M Yoshizawa,
T Yambe,
A Yamada,
M H Omran,
T Shiga,
T Kitano,
K Kamiya,
S Mochizuki,
H Miura,
D Homma,
M Yamagishi
[show abstract]
[hide abstract]
ABSTRACT: Total cavopulmonary connection (TCPC) is commonly applied for the surgical treatment of congenital heart disease such as single ventricle in pediatric patients. Patients with no ventricle in pulmonary circulation are treated along with Fontan algorithm, in which the systemic venous return is diverted directly to the pulmonary artery without passing through subpulmonary ventricle. In order to promote the pulmonary circulation after Fontan procedure, we developed a newly designed pulmonary circulatory assist device by using shape memory alloy fibers. We developed a pulmonary circulatory assist device as a non-blood contacting mechanical support system in pediatric patients with TCPC. The device has been designed to be installed like a cuff around the ePTFE TCPC conduit, which can contract from outside. We employed a covalent type functional anisotropic shape memory alloy fiber (Biometal, Toki Corporation, Tokyo Japan) as a servo actuator of the pulmonary circulatory assist device. The diameter of this fiber was 100 microns, and its contractile frequency was 2-3 Hz. Heat generation with electric current contracts these fibers and the conduit. The maximum contraction ratio of this fiber is about 7% in length. In order to extend its contractile ratio, we fabricated and installed mechanical structural units to control the length of fibers. In this study, we examined basic contractile functions of the device in the mock system. As a result, the internal pressure of the conduit increased to 63 mmHg by the mechanical contraction under the condition of 400 msec-current supply in the mock examination with the overflow tank of 10 mmHg loading.
Conference proceedings: ... Annual International Conference of the IEEE Engineering in Medicine and Biology Society. IEEE Engineering in Medicine and Biology Society. Conference 08/2011; 2011:8353-5.
-
[show abstract]
[hide abstract]
ABSTRACT: Aztreonam (E-0734, AZT) was administered to pneumonia and chronic respiratory tract infections. The results were as follows: AZT was administered to 29 patients. Twenty-six cases were evaluable and 3 cases were excluded from evaluation of efficacy because 1 was Gram-positive infection, 2 were unclear symptom of infection. Pneumonia was 4 cases. Chronic respiratory tract infections were 22 cases. Clinical efficacy was judged as follows; excellent in 7 cases, good in 10 cases, fair in 5 cases and poor in 4 cases, then the efficacy rate was 65.4%. Efficacy rate in pneumonia, acute aggravation of diffuse panbronchiolitis and bronchiectasis with infection was 50%, 67% and 83%, respectively. Bacteriological response was judged on 21 cases with eradication rate was 66.7%. Bacteriological response classified by pathogen was as follows: All 6 isolates of H. influenzae, 2 in 6 isolates of P. aeruginosa, 4 in 5 isolates of H. parainfluenzae and all 3 isolates of K. pneumoniae were cleared. Total eradicated rate was 74.1%. Eruption was observed in 1 case as side effect. Abnormal laboratory findings were observed in 4 cases. Elevation of GOT and GPT was in 3 cases. Increase of eosinophil and basophil was in 1 case. AZT was considered to be a useful antibiotic for the treatment of respiratory tract infections, especially chronic respiratory tract infections, caused by Gram-negative pathogens.
The Japanese journal of antibiotics 12/1985; 38(11):3415-33.
-
[show abstract]
[hide abstract]
ABSTRACT: A novel finding of mechano-catalytic overall water splitting by metal oxides, a way to produce hydrogen by water decomposition, is reported. It was clearly revealed that some simple and mixed oxide powders such as NiO, Co3O4, Cu2O, Fe3O4, and CuMO2 (M=Al, Fe, Ga), when suspended in distilled water by magnetic stirring, decompose water into H-2 and O-2 catalytically. The observed mechano-catalytic overall water splitting was cycled by the conversion of mechanical energy supplied by rubbing these oxide powders against the bottom wall of the reaction vessel with the stirring rod. Typical efficiency of the mechanical-to-chemical energy conversion was estimated to be 4.3% (for NiO).
Physical Chemistry Chemical Physics. 1(18):4485-4491.
-
[show abstract]
[hide abstract]
ABSTRACT: Superconducting nanowire single photon detectors (SNSPD) have unique characteristics of ultra low dark counts and wide spectrum sensitivity. These natures are indispensable for the evaluation of ultra-broadband parametric fluorescence, which are used for the quantum optical coherence tomography and novel optical non-linear experiments. Here we report the spectral dependence of the detection efficiency of a meander type SNSPD device, having reduced strip width of 50 nm, over a wide spectrum range up to near infra-red wavelength. The fiber coupled, meander type device was fabricated using 6 nm thick Niobium nitride (NbN) nanowires of reduced strip width, 50 nm, patterned over a MgO substrate with active area of 10 x 10 mu m(2). A maximum efficiency of 32% at 500 nm, 30% at 600 nm, 16% at 800 nm, 10% at 1000 nm, and 1% at 1550 nm with the normalized bias current of 0.95 (bias 37 mu A) was observed at 4.2 K. The salient feature of the device is, it exhibits a very low dark count rate (DCR) of only 2 Hz at the standard operating bias of 37 mu A and ultra low DCR of 0.01Hz at 34 mu A. Moreover, at this reduced bias with 0.01Hz DCR, the detection efficiency is not appreciably decreased in the visible region (32% at 500 nm and 30% at 600 nm) and an order decrease is observed (0.1%) at 1550 nm. The noise equivalent power (NEP) is of the order 10(-19) WHz(-1/2) in the visible region and 10(-17) WHz(-1/2) in the near IR region. Ultra-broad band parametric fluorescence of band width from 791 nm to 1610 nm generated by a quasi-phase matched (QPM) device was successfully detected with this SSPD.
Quantum Sensing and Nanophotonic Devices Ix. 8268.
