Comparative Study of Hydrogen- and Deuterium-Induced Degradation of Ferroelectric (Pb,La)(Zr,Ti)O3 Capacitors Using Time-of-Flight Secondary Ion Measurement.

Ferroelectric (Pb,La)(Zr,Ti)O3 (PLZT) capacitors were fabricated with Pt, Al:ZnO (AZO), or Sn:In2O3 (ITO) top electrodes. Hydrogen- or deuterium-induced degradation was investigated for the three capacitors by annealing in a 3% H2/balance N2 or 3% D2/balance N2 ambient environment at 200 °C and 1 torr. The remnant polarization of all capacitors decreased after annealing in both H2 and D2 ambient after 45 min, and the remnant polarization of the Pt/PLZT/Pt capacitor significantly decreased after 45-min annealing compared with that of the AZO/PLZT/Pt and ITO/PLZT/Pt capacitors, even though the initial remnant polarization for the Pt/PLZT/Pt capacitor was larger. Time-of-flight secondary ion mass spectrometry showed slight differences in hydrogen content for the three different capacitors after H2 annealing. In contrast, the deuterium content of the Pt/PLZT/Pt and AZO/PLZT/Pt or ITO/PLZT/PT capacitors was significantly different after deuterium annealing. Deuterium depth profiles for the Pt/PLZT/Pt capacitor after annealing showed that deuterium conformally exists in the PLZT layer of the Pt/PLZT/Pt capacitor, and deuterium accumulation under the Pt bottom electrode was also observed. This result suggests that diffusion of deuterium in Pt was much higher than that in PLZT. AZO and ITO top electrodes could act as a hydrogen barrier layer for ferroelectric films.

Yields and images of secondary ions from organic materials by different primary Bi ions in time-of-flight secondary ion mass spectrometry.

RATIONALE: Bi cluster ions are used as a source of primary ions for time-of-flight secondary ion mass spectrometry (TOF-SIMS), and it has been recognized that secondary ion yields of macromolecules are higher with Bi cluster ions than with monomer ions or other cluster ions such as Cs(+), Ga(+) and Aun (+). However, the analysis conditions of Bi cluster TOF-SIMS are not sufficiently established. This study provides information on the secondary ion yields, damage cross-section and spatial resolution obtained with different primary Bi ions. METHODS: We investigated the secondary ion yields, damage cross-section and spatial resolution using three different primary Bi ions in TOF-SIMS. The primary ions selected were Bi1(+), Bi3(+) and Bi3(2)(+) that were accelerated with 25 kV and the positively charged secondary ions were analyzed. The samples were 1, 2-distearoyl-sn-glycero-3-phosphocholine (C44H88NO8P, DSPC), which is a typical lipid, and N,N'-di(1-naphthyl)-N,N'-diphenylbenzidine (C44H32N2, NPD) and 4,4',4"-tris[2-naphthyl(phenyl)amino]triphenylamine (C66H48N4, 2-TNATA), which are organic functional materials. RESULTS: Although the secondary ion yields of DSPC were highest when measured with Bi3(+), the spatial resolution obtained from all DSPC analyses could not be evaluated because of the low intensity of the secondary molecular ions. On the other hand, for both NPD and 2-TNATA, the secondary ion yields were highest when imaged with Bi3(2)(+). Also, we obtained the highest spatial resolution using Bi3(2)(+). In the analysis of all molecules, the damage cross-section obtained with Bi3(2)(+) was also the highest. CONCLUSIONS: When secondary ions were sensitively detected, images of the high spatial resolution were obtained by using Bi3(2)(+). On the other hand, when the secondary ion sensitivity was low, the spatial resolution depended on the yields of secondary ions, implying that the selection of the primary ion species is crucial for SIMS analysis of large molecules.

Effects of molecular weight and cationization agent on the sensitivity of Bi cluster secondary ion mass spectrometry.

RATIONALE: Bi cluster secondary ion mass spectrometry (SIMS) is one of the most promising tools for precise analysis of synthetic polymers. However, the sensitivity in the high-mass region is still insufficient compared with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOFMS). Accordingly, the effects of metal assistance (cationization agents) were investigated in this study. METHODS: To investigate the effects caused by varying the ionization agent, three different polyethylene glycol (PEG) samples were prepared, one with an Ag-deposited film, and two others mixed with Ag and Na, respectively. The measurements were performed by using a commercial Bi cluster SIMS and MALDI-TOFMS systems. The mass spectrum obtained with MALDI-TOFMS was used as a reference molecular weight distribution to evaluate the effects of molecular weight and primary ion species (Bi+ , Bi3+ , Bi32+ ) on the sensitivity of Bi cluster SIMS. RESULTS: The intensity of each secondary ion was the highest in Bi32+ irradiation, and the lowest in Bi+ irradiation. Regarding the cationization agents, the secondary ion yield was the highest for the sample mixed with Ag, while the degree of decay of sensitivity along with the increase in molecular weight was the smallest for the sample mixed with Na. CONCLUSIONS: It was suggested that the cationization mechanism consists of pre-formed ionization and gas-phase ionization processes. The sensitivity of Bi cluster SIMS decreases to approximately one-fiftieth in every 1000 u. These results might help in understanding the mechanism of cationization and further enhancement of secondary ion yields of polymers. Copyright © 2016 John Wiley & Sons, Ltd.

Inhalation of budesonide/formoterol increases diaphragm muscle contractility.

BACKGROUND: Although budesonide/formoterol (BUD/FORM) is used clinically as a steroid/ß(2)-agonist single inhaler, it has not yet been clarified whether BUD/FORM has inotropic effects on diaphragm muscles after inhalation. METHODS: We examined the effects of BUD/FORM inhalation, endotoxin injection, and BUD/FORM inhalation plus endotoxin injection on diaphragm contractile properties and nitric oxide (NO) production. After these three treatments, the diaphragm muscle was dissected, and its contractile properties were measured. Histochemistry for the reduced form of nicotinamide adenine dinucleotide phosphate diaphorase was performed for each muscle to assess NO production. RESULTS: The force-frequency curves showed an upward shift 1 h after inhalation (p < 0.05) in the BUD/FORM inhalation only group. The force-frequency curves showed a downward shift 4 h after injection (p < 0.001) in the endotoxin injection groups. In the BUD/FORM inhalation plus endotoxin injection groups, a downward shift in the force-frequency curves at 4 h after endotoxin injection was prevented. NO production was inhibited in the BUD/FORM inhalation plus endotoxin injection group compared with that of the endotoxin injection only groups. CONCLUSIONS: BUD/FORM inhalation has an inotropic effect on diaphragm muscle, protects diaphragm muscle deterioration after endotoxin injection, and inhibits NO production. Increments in muscle contractility with BUD/FORM inhalation are induced through a synergistic effect of an anti-inflammatory agent and ß(2)-agonist.

Effects of inhalation or incubation of oxitropium bromide on diaphragm muscle contractility in mice.

BACKGROUND: Although oxitropium bromide is used clinically as an anticholinergic drug (i.e., parasympathetic antagonist) to relax airway smooth muscle, we examined whether it has or does not have any effects on diaphragm muscle. METHODS: Three treatment sets, an oxitropium bromide inhalation only group, an oxitropium bromide inhalation plus endotoxin injection group (in vivo) and an oxitropium bromide incubation group (in vitro) were studied as to diaphragm muscle contractile properties. RESULTS: Oxitropium bromide inhalation shifted force-frequency curves upward at 2 h after inhalation (p < 0.05) and inhibited the decrease of force-frequency curves due to endotoxin injection in vivo. Incubation with oxitropium bromide of untreated diaphragm muscle and diaphragm muscle injected with endotoxin did not increase the force-frequency curves dose-dependently in vitro; however, it caused both types of muscle to be fatigue resistant. CONCLUSIONS: We speculate that the increment of muscle contractility with the inhalation of oxitropium bromide was induced by the antagonization of musucarinic acetylcholine receptors (mAChR). In addition, the changes of fatigue resistance provoked by oxitropium bromide, which also is speculated to antagonize mAChR, may be beneficial in the treatment of patients with COPD.

Tulobuterol patch maintains diaphragm muscle contractility for over twenty-four hours in a mouse model of sepsis.

Tulobuterol, a sympathomimetic drug used as a transdermal patch, increases normal diaphragm muscle strength. Because diaphragm muscle weakness (i.e. decrease of contraction) is a feature of bronchial asthma and sepsis, we examined the in vitro and in vivo effects of tulobuterol on the contractility of diaphragm muscles prepared from mice treated with endotoxin. We measured contractile parameters of force-frequency curves and twitch kinetics using untreated or treated diaphragm muscles at 0 (E0) and 4 (E4) hours after E. coli endotoxin (20 mg/kg) administration. The force-frequency curve of E4 diaphragm muscle was decreased from that of E0 diaphragm muscle (p < 0.001). E4 diaphragm muscle was incubated in an organ buffer containing 10(-7) or 10(-5) M concentrations of tulobuterol for 1 h (in vitro). The force-frequency curves of both 10(-7) (p < 0.01) or 10(-5) M (p < 0.001) tulobuterol concentrations shifted significantly upward from those of no tulobuterol, indicating that tulobuterol can recover the diaphragm muscle contractility that was decreased by endotoxin. In the in vivo treatment, E0 and E4 diaphragm muscles were analyzed at 0, 12, and 24 h after transdermal tulobuterol treatment. The force-frequency curves of E0 and E4 diaphragm muscles at three time points were not significantly changed each other, indicating that tulobuterol patch restores the muscle contractility. Thus, diaphragm muscle contractility was maintained during 4 h of endotoxin administration with tulobuterol patch for over 24 h. We suggest that this treatment of bronchial asthma may protect against endotoxin contained in inhaled house dust.