Elliptocytosis in myelodysplastic syndrome associated with translocation (1;5)(p10;q10) and deletion of 20q

OBJECTIVE: To assess the efficacy of prolonged high pressure angioplasty for dilatation of calcified and stenotic cardiac conduits in children. DESIGN: A prospective study of consecutive patients presenting with calcified and stenotic conduits. SETTING: Two tertiary paediatric cardiology departments. METHODS: Sustained (up to five minutes), high pressure (up to 18 atmospheres), double balloon angioplasty was performed in six calcified and stenotic cardiac conduits (five consecutive patients, three male, two female, age 4 to 17 years). Four patients had right ventricle to pulmonary artery (RV-PA) conduits, and one had two venous conduits in a Fontan circulation. RESULTS: Marked reductions in right ventricle to pulmonary artery gradients, from a median (range) of 48 (40 to 62) mm Hg to 11 (5 to 16) mm Hg, and in right ventricle to femoral artery pressure ratios, from a median of 0.8 (0.72 to 0.86) to 0.4 (0.33 to 0.44), were achieved for all RV-PA conduits. All five patients had sustained clinical improvement at follow up (median follow up 12 months) and none has required reintervention or surgery. CONCLUSIONS: Prolonged high pressure double balloon angioplasty may have a role in prolonging the interval between conduit replacements in a subset of patients with complex heart defects.     

Effects of Intergranular Phase Chemistry on the Microstructure and Mechanical Properties of Silicon Carbide Ceramics Densified with Rare-Earth Oxide and Alumina Additions

Based on the processing strategy of improving the mechanical properties of liquid-phase-sintered materials by modifying the secondary phase chemistry, four rare-earth oxides (RE₂O₃, RE = La, Nd, Y, and Yb), in combination with alumina, were used as sintering aids for a submicrometer-size β-SiC powder. Doped with 5 vol% RE₂O₃+ Al₂O₃ additives, all specimens were hot-pressed to near full-densities at 1800°C, and they exhibited similar microstructures and grain size distributions. The SiC grains in all specimens revealed a core-rim structure after being plasma-etched, indicating that they were densified via the same solution-reprecipitation mechanism. It was found that a decrease in the cationic radius of the rare-earth oxides was accompanied by an increase in Young's modulus, hardness, and flexural strength of the SiC ceramics, whereas the fracture toughness was improved by incorporating rare-earth oxides of larger cationic radius. The changes in the mechanical properties were attributed to the difference in the chemistry of the intergranular phases in the four ceramics.     

Performance of a shower maximum detector with avalanche photodiode readout

We have constructed a shower maximum detector (SMD) using 1-cm wide scintillating strips. The SMD measures the position of electrons and photons in the electromagnetic calorimeter, and improves the e/π separation capability. We use avalanche photodiodes (APDs) to read out the scintillation light; they are directly attached to each end of a strip so as to construct a compact detector. We operate the SMD at room temperature. This report describes the structure of the SMD and its performance as measured in beam tests for future linear collider experiments.     

MgSiN2 Addition as a Means of Increasing the Thermal Conductivity of β-Silicon Nitride

Si₃N₄ powders with the concurrent addition of Yb₂O₃ and MgSiN₂ were sintered at 1900°C for 2–48 h under 0.9 MPa nitrogen pressure. Microstructure, lattice oxygen content, and thermal conductivity of the sintered specimens were evaluated and compared with Si₃N₄, Yb₂O₃, and MgO addition. MgSiN₂ addition was effective for improving the thermal conductivity of Si₃N₄ ceramics, and a material with high thermal conductivity over 140 W·(m·K)⁻¹ could be obtained. For both specimens, lattice oxygen content was decreased with sintering time. However, the thermal conductivity of the MgSiN₂-doped specimen was slightly higher than the MgO-doped specimen with the same oxygen content.     

Efficient decomposition of perfluorocarboxylic acids and alternative fluorochemical surfactants in hot water

Decomposition of C5-C9 perfluorocarboxylic acids (PFCAs) and perfluoroether carboxylic acids (alternatives to PFCA-based surfactants) in hot water in a sealed reactor was investigated. Although PFCAs showed almost no decomposition in hot water at 80 degrees C in the absence of persulfate (S2O8(2-)), the addition of S2O8(2-) to the reaction system led to efficient decomposition, even at this relatively low temperature. The major products in the aqueous and gas phases were F- ions and CO2, respectively, and short-chain PFCAs were also detected in the aqueous phase. For example, when an aqueous solution containing perfluorooctanoic acid (PFOA, 374 microM) and S2O8(2-) (50.0 mM) was heated at 80 degrees C for 6 h, PFOA concentration in the aqueous phase fell below 1.52 microM (detection limit of HPLC with conductometric detection), and the yields of F- ions [i.e., (moles of F- formed) /(moles of fluorine content in initial PFOA)] and CO2 [i.e, (moles of CO2 formed) /(moles of carbon content in initial PFOA)] were 77.5% and 70.2%, respectively. This method was also effective in decomposing perfluoroether carboxylic acids, such as CF3OC2F4OCF2COOH, CF3OC2F4OC2F4OCF2COOH, and C2F5OC2F4OCF2COOH, which are alternatives to PFCA-based surfactants, producing F- and CO2 with yields of 82.9-88.9% and 87.7-100%, respectively, after reactions at 80 degrees C for 6 h. In addition, the method was successfully used to decompose perfluorononanoic acid in a floor wax solution. When PFOAwastreated at a higher temperature (150 degrees C), other decomposition reactions occurred: the formation of F- and CO2 was dramatically decreased, and 1H-perfluoroalkanes (C(n)F(2n+1)H, n = 4-7) formed in large amounts. This result clearly indicates that treatment with high-temperature water was not suitable for the decomposition of PFCAs to F-: surprisingly, the relatively low temperature of 80 degrees C was preferable.     

Reversible Fluorescent On–Off Recording in a Highly Transparent Polymeric Material Utilizing Fluorescent Resonance Energy Transfer (FRET) Induced by Heat Treatment

One productive technique for ultrahigh resolution readout of tiny regions is the measurement of the fluorescence signal of materials. A transparent polymeric materials whose fluorescence quantum yield is changed and recorded by thermally controlling the aggregation of fluoran dyes and developers with long alkyl chains has been developed. The recording medium can be fabricated easily by casting or coating recording materials. Fluorescence is observed after annealing at 363 K for about twelve seconds and then cooling to room temperature (RT), and quenched by annealing at 423 K for a few seconds and then quenching to RT. Nondestructive readout by excitation light with a fluorescent contrast of above 10 is achieved using red, green, and blue fluorescent dyes. Fluorescence on–off switching is induced by fluorescent resonance energy transfer (FRET) from a fluorescent dye to a colored fluoran dye in the recording material. Fluorescence was uniformly quenched in the visible region after erasing. Since the recording materials allow the penetration of laser light due to the presence of crystals smaller than the wavelength range of visible light in both the emission and quenching states, nondestructive readout of the fluorescent signal by two‐photon absorption is accomplished. This work provides an important stepping‐stone for achieving rewritable‐type near‐field optical storage or multilayer recording.     

Efficient decomposition of environmentally persistent perfluorooctanesulfonate and related fluorochemicals using zerovalent iron in subcritical water

Decomposition of perfluorooctanesulfonate (PFOS) and related chemicals in subcritical water was investigated. Although PFOS demonstrated little reactivity in pure subcritical water, addition of zerovalent metals to the reaction system enhanced the PFOS decomposition to form F-ions, with an increasing order of activity of no metal approximately equal Al < Cu < Zn < Fe. Use of iron led to the most efficient PFOS decomposition: When iron powder was added to an aqueous solution of PFOS (93-372 microM) and the mixture was heated at 350 degrees C for 6 h, PFOS concentration in the reaction solution fell below 2.2 microM (detection limit of HPLC with conductometric detection), with formation of F-ions with yields [i.e., (moles of F- formed)/(moles of fluorine content in initial PFOS) x 100] of 46.2-51.4% and without any formation of perfluorocarboxylic acids. A small amount of CHF3 was detected in the gas phase with a yield [i.e., (moles of CHF3)/(moles of carbon content in initial PFOS) x 100] of 0.7%, after the reaction of PFOS (372 microM) with iron at 350 degree C for 6 h. Spectroscopic measurements indicated that PFOS in water markedly adsorbed on the iron surface even at room temperature, and the adsorbed fluorinated species on the iron surface decomposed with rising temperature, with prominent release of F- ions to the solution phase above 250 degrees C. This method was also effective in decomposing other perfluoroalkylsulfonates bearing shorter chain (C2-C6) perfluoroalkyl groups and was successfully applied to the decomposition of PFOS contained in an antireflective coating agent used in semiconductor manufacturing.     

Confirmation of non-permitted dyes detected in Akasu (red vinegar) by LC/MS

Suitable liquid chromatography/mass spetrometry (LC/MS) conditions were examined for Amaranth, Red 2G (R2G), Azo Rubine (Azo), Fast Red E (FRE) and Brilliant Blue FCF, which were detected in Akasu, a red vinegar made in Hong Kong from sake lees, on both thin layer chromatography (TLC) and photodiode array high-performance liquid chromatography (PDA-HPLC). Molecular-related ions for each dye were detected with excellent sensitivity by LC/MS using electro-spray ionization with negative ion mode, capillary voltage 3.00 kV, cone voltage 50 V and desolvation temperature 400 degrees C. LC/MS analysis of refined Akasu under these conditions enabled us to obtain clear mass spectra of R2G, Azo and FRE, which were present at trace levels in the Akasu. The results were consistent with those from TLC and PDA-HPLC. These experiments suggested that LC/MS analysis is applicable for confirmation of dyes in food.     

Application of the independent molecule model to the calculation of free energy and rigid-body motions of water heptamers and octamers

Stabilization of clusters of water heptamer and octamer in the gas phase is studied with the independent molecule model. As indicators of stabilization, the H-bonding strength, the H-bonding lifetime and the free energy are calculated. For both the heptamers and octamers, clusters with one oxygen-ring and some branching H-bonded waters are more stable than clusters with multi-oxygen-rings. Both the heptamer and octamer prefer a shape intermediate between planar and polyhedral; the branched waters are highly fluctuating and consequently contribute to increasing the entropy of the cluster. As the temperature increases from 0 to 300 K, the entropy contributes to the differentiation in free energy of the cluster geometries.     

Proposal of Integrated Test Facility for in-Vessel Thermofluid Safety of Fusion Reactors

A vacuum vessel (VV) of a tokamak fusion reactor like the International Thermonuclear Experimental Reactor (ITER) consists the first confinement barrier that includes the largest amount of radioactive materials such as tritium and activation products. The ingress of coolant event (ICE) is a design basis event in the ITER where water is used as the coolant. The loss of vacuum event (LOVA) is also considered as an independent design basis event. Based on the results of ICE and LOVA preliminary experiments, an integrated in-vessel thermofluid test is being planned and conceptual design of the facility is in progress. The main objectives of the integrated test are to investigate the consequences of possible interaction of the ICE and the LOVA and to validate the analytical model of thermofluid events in the VV of the fusion reactor. This paper introduces a conceptual design of the integrated test facility and a testing plan.