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Objective: We sought to investigate whether left atrial (LA) appendage (LAA) function was impaired in patients with systemic embolism in sinus rhythm. Methods: Transesophageal echocardiography was performed in 7 patients within 5 days after embolism (early group) and in 32 patients, more than 5 days after embolism (late group). We searched intracardiac thrombus and determined LAA area and LAA flow velocity, and the grade of spontaneous echocontrast. Results: LA thrombus could be detected in 2 of the 39 patients only in early group (P = .028). The patients of early group, as compared with late group, had lower LAA flow velocity (28 +/- 16 vs 60 +/- 26 cm/s, P = .007) and higher grade of spontaneous echocontrast score (1.14 +/- 1.46 vs 0.25 +/- 0.62, P = .013). LA dimension and LAA area were not statistically different. Conclusion: LAA function may be impaired early after embolism even in sinus rhythm.

An ion-exchanger H8Nb22O59·8H2O was prepared by extracting Rb⁺ from Rb8Nb22O59, and its ion-sieve properties for alkali metal ions were investigated. The Rb⁺ can be effectively extracted using a concentrated HNO3 solution at room temperature, leading to a protonated compound with composition of Rb0.14H7.9Nb22O59·8.2H2O. The protonated (hydronium ion form) crystal has the lattice parameters (a = 7.5104(2) and c = 43.0780(8) Å of hexagonal symmetry, R&thremacr;m), very close to the Rb⁺-form precursor. The exchange capacity increased in the order Cs⁺ ≪ Rb⁺ < K⁺, Na⁺ < Li⁺, which agrees with the decreasing order of ionic radius. The capacities for Li⁺, Na⁺, and K⁺ were close to the theoretical value of 2.55 mmol/g calculated from the composition of protonated compound. The distribution coefficients (Kd) of alkali metal ions were determined in the condition of microamount of ion loading. The selectivity sequence was Cs⁺, Li⁺ ≪ Na⁺ < Rb⁺ ≪ K⁺ at pH around 3; the protonated samples showed markedly high selectivity for the adsorption of K⁺. The pH titration curves showed a mono-base acid character toward Na⁺, K⁺, and Rb⁺ ions. The analysis based on the ion-exchange model showed that it has a large amount of uniform acidic sites up to the neutralization degree of 0.5. The intrinsic acidities, pK0 values, were evaluated as 1.6 for Na⁺, K⁺, and Rb⁺ exchanges; this indicates that the ion-exchange sites have relatively strong acidity. The removal of Na⁺ and K⁺ impurities from Li⁺-concentrated solutions was studied, and the removal rates for Na⁺ and K⁺ were found to reach 98 and 99.9%, respectively, from a solution containing 410 mM LiCl, 20 mM LiOH, 4.3 mM NaCl, and 1.0 mM KCl.

We report in this paper the studies on protonation, exfoliation, and self-assembly of birnessite-type manganese oxide single crystals. The protonation was carried out by extracting K⁺ ions from the potassium manganese oxide single crystals in a (NH4)2S2O8 aqueous solution heated at 60 °C, exfoliation to nanosheets by the intercalation of TMA⁺ ions followed by water-washing, and the self-assembly of MnO2 nanosheets in a dilute NaCl solution. The structures of the samples at these stages were systematically investigated using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, Fourier transform infrared, thermogravimetric analysis-differential thermal analysis, and chemical compositional analysis. Electron density distribution in the protonated single crystal was visualized by whole-pattern fitting based on the maximum entropy method. The results indicated that the protonated single crystals can be exfoliated to MnO2 unilamellar nanosheets. The self-assembly yields layered crystals with basal spacing of 0.72 nm and with a composition of H0.18Na0.089MnO2·0.47H2O. The layered crystals had a textured polycrystalline structure, where c-axes of the nanosheets aligning along a certain direction constitute a fiber axis with azimuthal orientations of a- or b-axes about the fiber axis. Moreover, the azimuthal orientations of a- or b-axes are probably arranged at particular angles to one another, rather than randomly. The mean oxidation state of manganese exhibits no marked change at the various stages of the protonation, exfoliation, and self-assembly.

A layered manganese oxide nanocomposite (PDDAMO) with poly(diallyldimethylammonium chloride), PDDA, incorporated between manganese oxide sheets, was synthesized by a delamination/reassembling process. The product was characterized by powder X-ray diffraction, elemental analysis, thermal analysis, FT-IR spectroscopy, and FE-SEM observation. XRD analysis showed that the expansion of the interlayer depended on the amount of PDDA intercalated; the largest expansion was 1.09 nm, corresponding to a bilayer of PDDA chains in the interlayer. Chemical analysis results showed that the PDDA intercalation progressed by an ion-exchange mechanism, and the PDDA polymer existed in a polycation form, not as a chloride salt. PDDAMO was comprised of platelike nanocomposite particles that were 1−5 μm in width. The thickness of each plate was 30 nm on average, which corresponds to the stacking of about 20 sheets of manganese oxide. The formation of the PDDAMO nanocomposite was hardly affected by the pH of the solution. PDDAMO had a high stability against extraction by acid treatment, probably due to the strong electrostatic attraction between manganese oxide sheets and PDDA chains.

A series of mixed layered Ni(OH)2−manganese oxides with Ni/Mn molar ratios up to near 1 were prepared by using a novel exfoliation−restacking hydrothermal method and a hydrothermal intercalation method. A series of lithium nickel manganese oxides with hexagonal layered structure (space group R&thremacr;m) can be obtained by hydrothermal treatment of the mixed layered Ni(OH)2−manganese oxides in a concentrated LiOH solution at 200 °C. Another type of lithium nickel manganese oxide with an α-LiFeO2-like cubic structure can be obtained by using NiMnO3 as precursor under similar hydrothermal conditions. The synthesis reactions and the products were investigated by XRD, TEM, TG−DTA, and XPS studies. The mixed layered structure of Ni(OH)2−manganese oxides can be described by two sublattices having different hexagonal unit-cell parameters in the ab plane but a common periodicity perpendicular to them along c. The layered lithium nickel manganese oxides can be expressed by a general formula of {Lix}[LiyNinMnm]O2 (x ≤ 1, y ≤ ¹/3, (y + n + m) ≤ 1). The cubic phase of lithium nickel manganese oxide is metastable, which transforms to the hexagonal layered phase after heating at 500 °C in air.

We examined the synthesis and borate uptake of novel chelating resins, named MGR and HMR, derived from the functionalization of macroporous poly(glycidyl methacrylate-co-trimethylolpropane trimethacrylate) matrixes with N-methyl-d-glucamine (MG) and 2-amino-2-(hydroxymethyl)-1,3-propanediol (HM), respectively. The structures of free matrixes, resins, and borate-loaded resins were confirmed by infrared spectroscopy. The borate uptake depends significantly on the proton capacity, which is proportional to the GMA fraction in matrixes, but little on the pore structure of macroporous matrixes. The ion-exchange isotherms of borate on MGR and HMR follow the Langmuir equation. MGR shows a larger uptake capacity toward borate than does HMR, comparable to that of Diaion CRB 02, because the tetradentate coordination mode of the former is more stable than the bidentate one of the latter. MGR exhibits a higher rate of borate uptake than does Diaion CRB 02, and the uptake kinetics are explained from a macropore diffusion model.

The reduced partition function ratio for lithium ions in an aqueous solution is derived from the extrapolation of the values of the reduced partition function ratio (%@mt;sys@%%@ital@%f%@rsf@% %@sx@%%@ital@%n%@rsf@%%@be@%r%@sxx@%%@mx@% ) of hydrated lithium ion clusters [Li(H2O)n]⁺ up to n = 6. In [Li(H2O)n]⁺ clusters, the %@mt;sys@%%@ital@%f%@rsf@% %@sx@%%@ital@%n%@rsf@%%@be@%r%@sxx@%%@mx@% values can be calculated from the normal vibration frequencies according to Bigeleisen and Mayer's theory. To obtain the values of %@mt;sys@%%@ital@%f%@rsf@% %@sx@%%@ital@%n%@rsf@%%@be@%r%@sxx@%%@mx@% , the normal vibration frequency calculations were carried out for optimized structures of [Li(H2O)n]⁺ (n = 1−6) using the RHF/6-31+G(d), RHF/6-31++G(d,p), RHF/6-311+G(d) and MP2/6-31+G(d) methods by means of the ab initio molecular orbital method. All of those structures having high symmetry were confirmed to have real harmonic frequencies at the RHF/6-31+G(d) and RHF/6-31++G(d,p) levels. For the two RHF methods, the value of %@mt;sys@%%@ital@%f%@rsf@% %@sx@%%@ital@%n%@rsf@%%@be@%r%@sxx@%%@mx@% increases to about 1.07 with an increase of the hydration number n, and reaches maximum at n = 4. In the most stable isomers of [Li(H2O)n]⁺ clusters for n = 5 and 6, respectively, the first hydration shell is saturated with the four water molecules, and the size dependence of the %@mt;sys@%%@ital@%f%@rsf@% %@sx@%%@ital@%n%@rsf@%%@be@%r%@sxx@%%@mx@% values converges for n ≥ 4. The converged value 1.07 can, therefore, be regarded as the reduced partition function ratio for lithium ions in aqueous solution, and gives the upper limit of the isotopic separation factor in an aqueous solution−exchanger system.

Mg+ ions were implanted into highly pure InP grown by the liquid encapsulated Czochralski (LEC) method in which the Mg concentration [Mg] was varied between 1×1015 cm-3 and 3×1020 cm–3. Two annealing methods were used: furnace annealing (FA) up to 740° C and flash lamp annealing (rapid thermal annealing, RTA) up to 900° C. For characterization, photoluminescence (PL) spectra were measured between 2K and room temperature together with Raman scattering measurements at room temperature. An emission designated by g, which was attributed to a novel energy state of an isolated acceptor, was found to be produced for a rather low value of [Mg]. In addition, a broad emission denoted by [g-g], which was ascribed to acceptor-acceptor pairs, was observed below bound exciton emissions for moderate values of [Mg]. These features were quite similar to those previously observed in acceptor-doped GaAs when the background concentration of donors is extremely low. Two additional novel emissions located far below the band-to-acceptor emission were also obtained, and each showed a remarkable energy shift towards lower energy with increasing [Mg]. The binding energies of these emissions were estimated from the temperature dependence of PL spectra and the results suggest that they are complex-type radiative recombination centers, presumably donor-acceptor-type centers. A strong broad emission centered near the band-to-acceptor emission was observed for [Mg]=3×1020 cm-3. This observation indicates a formation of a new material between In, P and Mg, which was also attested by the appearance of a new TO-like Raman signal for [Mg] greater than 1×1019 cm-3. A substantial difference of PL and Raman spectra was revealed for the two annealing methods, suggesting that the annealing behaviour of ion-implanted InP should be investigated more extensively in order to establish reliable annealing procedures.