Geranylgeranylacetone, an anti-ulcer drug, stimulates hexosamine production in a rat gastric mucosal cell line through binding to a specific cytosolic protein

It is not known whether patients with acute myocardial infarction (MI) with coexistent obstructive sleep apnea (OSA) have a poor clinical course during the acute phase of MI. Therefore, we investigated the impact of OSA on in-hospital morbidity and mortality during an acute MI. Patients admitted to the intensive cardiac unit (ICU) with acute MI underwent Holter monitoring and night pulse oximetry (SpO2). During the first complete day at the ICU, both recordings (ECG and SpO2) were matched in time to determine association between cardiac arrhythmias and hypoxemia episodes. We identified and compared 55 heavy snorers with daytime sleepiness who showed more than 10 episodes of desaturation per hour on pulse oximetry (OSA group), and 196 nonOSA patients. There was an increase in the incidence of premature ventricular contraction (PVC, p < 0.05) and couplets PVC (p < 0.05) in OSA patients; the proportion of those arrhythmias increased in parallel with desaturation episodes in the OSA group. There were no differences between OSA and nonOSA groups for major MI complications (38.2% vs 34.2%, p > 0.05), ICU/hospital stay (3.6 +/- 1.2 vs 2.7 +/- 0.9 days, p > 0.05), or mortality within 30 days (14.5% vs 12.2%, p > 0.05). In conclusion, despite the greater incidence of some types of cardiac arrhythmias during an acute MI in OSA, these patients have the same clinical course in hospital and mortality rate as nonOSA patients.     

Optimal current control methods of a non‐salient pole hybrid field‐synchronous motor for energy‐efficient and wide speed‐range operation

This paper proposes new practical optimal current control methods for a newly emerging class of non‐salient pole synchronous motors with hybrid rotor fields by both permanent magnet and winding. In practical situations with limited voltage, the extensively used permanent magnet synchronous motor hardly achieves an ideal performance that allows simultaneously both low‐speed high‐torque and wide speed‐range operations, due to its constant magnet field. Hybrid field synchronous motors (HFSM) have recently emerged to achieve ideal performance as practical motors with controllable hybrid rotor field. For HFSM, the same torque can be produced by a variety of currents due to nonlinearity between torque and currents. Consequently, appropriate determination of a set of stator and rotor current commands plays a key role in achieving possible energy‐efficient and wide speed‐range operation. Proposed methods determine the current commands corresponding to a given torque command such that total winding copper loss due to stator and rotor currents can be minimized if the exact solution exists; the best approximate torque can be produced if no exact solution exists. The determined current commands are optimal in the sense of energy efficiency or degree of approximation in wide speed‐range operation under voltage limit. New real‐time recursive algorithms searching the optimal current solution are also given. The proposed methods are analytical but practical, and their usefulness is verified through experiments. © 2006 Wiley Periodicals, Inc. Electr Eng Jpn, 156(1): 70–83, 2006; Published online in Wiley InterScience ( www.interscience. wiley.com ). DOI 10.1002/eej.20156     

The influence of people’s culture and prior experiences with Aibo on their attitude towards robots

This paper presents a cross-cultural study on peoples’ negative attitude toward robots. 467 participants from seven different countries filled in the negative attitude towards robots scale survey which consists of 14 questions in three clusters: attitude towards the interaction with robots, attitude towards social influence of robots and attitude towards emotions in interaction with robots. Around one half of them were recruited at local universities and the other half was approached through Aibo online communities. The participants’ cultural background had a significant influence on their attitude and the Japanese were not as positive as stereotypically assumed. The US participants had the most positive attitude, while participants from Mexico had the most negative attitude. The participants from the online community were more positive towards robots than those not involved. Previous experience in interacting with Aibo also had a positive effect, but owning an Aibo did not improve their attitude.     

Tip-sample distance control using photothermal actuation of a small cantilever for high-speed atomic force microscopy

We have applied photothermal bending of a cantilever induced by an intensity-modulated infrared laser to control the tip-surface distance in atomic force microscopy. The slow response of the photothermal expansion effect is eliminated by inverse transfer function compensation. By regulating the laser power and regulating the cantilever deflection, the tip-sample distance is controlled; this enables much faster imaging than that in the conventional piezoactuator-based z scanners because of the considerably higher resonant frequency of small cantilevers. Using this control together with other devices optimized for high-speed scanning, video-rate imaging of protein molecules in liquids is achieved.     

Probabilistic inverse analysis for predicting the distribution of multiple internal defects

A concept and a method of probabilistic inverse analysis are proposed for predicting the distribution of internal defects from their two-dimensional image on a cross-section. In this paper, circular (penny-shaped) cracks are chosen as a subject for analysis and a discussion is made on their statistical distribution. The spatial distribution of internal cracks, i.e. the number of cracks in a unit volume and the distribution of crack radius, is inversely predicted from the areal distribution of cracks observed on a cross-section, i.e. the number of cracks in a unit area and the distribution of crack length. When enough information on the areal distribution is given, for example, when a number of intercepted cracks can be observed on a cross-section for dense internal cracks, the spatial distribution of internal cracks is deterministically analyzed. Conversely, when the information is limited in the cross-sectional observation, a unique distribution of internal cracks cannot be determined. Then, a method of probabilistic inverse analysis is proposed. After the validity of the method is confirmed by numerical simulation, it is applied to actual internal cracks which initiate inside the specimens under a creep-fatigue condition. The distribution of internal cracks is successfully predicted.     

Physical and mechanical properties of municipal solid waste incineration residues with cement and coal fly ash using X-ray Computed Tomography scanners

A significant volume of Municipal Solid Waste incineration bottom ash and fly ash (i.e., incineration residues) are commonly disposed as landfill. Meanwhile, reclamation of landfill sites to create a new land space after their closure becomes an important goal in the current fewer and fewer land availability scenario in many narrow countries. The objective of this study is to reclaim incineration residue materials in the landfill site by using cement and coal fly ash as stabilizers aiming at performing quality check as new developed materials before future construction. Indeed, physical and mechanical properties of these new materials should be initially examined at the micro scale, which is the primary fundamental for construction at larger scale. This research examines quantitative influences of using the combination of cement and coal fly ash at different ratio on the internal structure and ability of strength enhancement of incineration residues when suffering from loading. Couple of industrial and micro-focus X-ray computed tomography (CT) scanners combined with an image analysis technique were utilized to characterize and visualize the behavior and internal structure of the incineration residues-cement-coal fly ash mixture under the series of unconfined compression test and curing period effect. Nine types of cement solidified incineration residues in term of different curing period (i.e., 7, 14, 28 days) and coal fly ash addition content (i.e., 0%, 9%, 18%) were scanned before and after unconfined compression tests. It was shown that incineration residues solidified by cement and coal fly ash showed an increase in compression strength and deformation modulus with curing time and coal fly ash content. Three-dimension computed tomography images observation and analysis confirmed that solidified incineration residues including incineration bottom and fly ash as well as cement and coal fly ash have the deliquescent materials. Then, it was studied that stabilized parts play a more important role than spatial void distribution in increment or reduction of compression strength.     

Two-Dimensional Mapping of Er3+ Photoluminescence in CaF2 Crystal Lines Patterned by Lasers in Oxyfluoride Glass

The laser-induced crystallization method is applied to an oxyfluoride glass with the composition of 41.5SiO₂–21.3Al₂O₃–4.8CaO–12.6NaF–16.4CaF₂–2.9NiO–0.5ErF₃ (mol%), and the lines consisting of CaF₂ nanocrystals (diameter: ∼20 nm) are patterned on the glass surface. It is found from micro-photoluminescence (PL) spectra of Er³⁺ ions that Er³⁺ ions are incorporated into CaF₂ nanocrystals formed by laser (continuous-wave Yb:YVO₄ fiber laser with a wavelength of 1080 nm) irradiations. Two-dimensional mappings of the PL intensity for the ⁴S_3/2→⁴I_15/2 transition of Er³⁺ ions are measured for the surface and cross section of the patterned lines. It is found that two phases giving different PL intensities are formed in the laser-irradiated region, suggesting that the center part of the laser-irradiated region consists of Er³⁺-doped CaF₂ nanocrystals and the surrounding of the center part gives the fluoride ion rich coordination state for Er³⁺ ions. The formation mechanism of Er³⁺-doped CaF₂ nanocrystals is related to the temperature distribution of the laser-irradiated region.     

Iron nanoparticles dispersible in both ethanol and water for direct silica coating

An amphiphilic polymer dispersant-polyvinyl pyrrolidone (PVP)-was used as a dispersant to make iron suspensions. The stability of the suspensions was characterized by conducting UV/vis transmittance and rheological analyses and sedimentation tests. We found that PVP was not only effective in dispersing iron nanoparticles in ethanol, but also in stabilizing them in deionized water by coordination interaction through its carbonyl group. The iron nanoparticles functionalized with PVP have another advantage: they could be directly used to coat a silica layer without further modification by other surfactants.