A smooth impact rotation motor using a multi-layered torsional piezoelectric actuator

A smooth impact rotation motor was fabricated and successfully operated using a torsional piezo actuator. Yoshida et al. reported a linear type smooth impact motor in 1997. This linear motor demonstrated a high output force and a long stroke. A superior feature of the smooth impact drive is a high positioning resolution compared with an impact drive. The positioning resolution of SIDM (smooth impact drive mechanism) is equal to the piezo displacement. The reported positioning resolution of the linear type was 5 nm. Our rotation motor utilized a torsional actuator containing multi-layered piezoelectric material. The torsional actuator was cylindrical in shape with an outer diameter of 15 mm, an inner diameter of 10 mm, and a length of 11 mm. Torsional vibration performance was measured with a laser Doppler vibrometer. The obtained torsional displacement agreed with the calculated values and was sufficient to drive a rotor. The rotor was operated with a saw-shaped input voltage (180 V; 8 kHz). The revolution direction was reversible. The maximum revolution speed was 27 rpm, and the maximum output torque was 56 gfcm. In general, smooth-impact drives do not show high efficiency; however, the level of efficiency of our results (max., 0.045%) could be increased by improving the contact surface material. In addition, we are studying quantitative consideration, for example, about the optimum pre-load or frictional force.     

Enantioseparation of atropisomeric 1,1'-binaphthyl-2,2'-diyl hydrogen phosphate in capillary electrophoresis by using di- and oligosaccharides as chiral selectors: di- and oligosaccharide chiral selectors in capillary electrophoresis

Twelve different disaccharides and a series of noncyclic malto- and cello-oligosaccharides were used as chiral selectors in capillary electrophoresis (CE). Most saccharides resolved the enantiomers of atropisomeric 1,1'-binaphthyl-2,2'-diyl hydrogen phosphate (BDHP) depending on the type (alpha or beta) and position of the linkage between monosaccharides. The effect of chain length of malto- and cello-oligosaccharides on enantioseparation of BDHP was also investigated. The nature of cations in background electrolytes affected significantly the separation of BDHP enantiomers.     

Effect of transient cyclic AMP elevation on DNA synthesis in rat hepatocytes at G1 phase

Maintaining high levels of intracellular cyclic AMP (cAMP) is known to inhibit the growth of various proliferating cells including hepatocytes. We show here that transient (30 min) elevations of cAMP induced by addition of 8-bromo-cAMP (1 mmol/L) to rat hepatocytes in primary culture at three time points (12 h, 16 h and 20 h) after seeding stimulated DNA synthesis. Sustained levels of cAMP stimulated DNA synthesis to a lesser degree at a lower concentration (1 mumol/L), but inhibited it at concentrations higher than 100 mumol/L. We also determined cyclin-dependent kinase 2 (cdk2) activity in the hepatocytes during this incubation period. The transient addition of 8-bromo-cAMP at the late G1 phase increased cdk2 activity. This suggests that transient cAMP elevation in hepatocytes at the late G1 phase has a growth stimulation effect. Up-regulation of cdk2 activity may have a role in this process.     

Hearing recovery in sudden deafness with profound hearing loss

To more completely describe acromion morphology and its relationship to impingement syndrome, we performed three-dimensional magnetic resonance imaging (N = 111) or computed tomography (N = 27) on 132 symptomatic shoulders. The mean patient age was 46.2 years (range, 14 to 86). Four parameters were evaluated: the angle of anterior slope of the acromion in the midsagittal and lateral-sagittal planes, lateral acromial angulation in the coronal plane, and the presence or absence of medial encroachment in the acromioclavicular joint. Twenty-five asymptomatic age-matched shoulders were used as controls. All imaging data were combined because no significant differences existed between the two imaging techniques. The mean acromion angle was 19.4 degrees in the midsagittal plane and 20 degrees in the lateral-sagittal plane. In the coronal plane, 97 (73%) acromions were neutral and 35 (27%) were downward sloping. Medial encroachment was present in 31 (24%) shoulders. Age distribution from the 2nd to 8th decade demonstrated a consistent and gradual transition from a flat acromion in the younger decades to a more hooked acromion in the older decades that was significant in both the midsagittal and lateral-sagittal planes. Furthermore, a greater percentage of patients were found to have downward angulating acromions with increasing age. Ninety-eight patients (74%) had stage II or III impingement. Of these shoulders, 39 (40%) had type I acromions, 51 (52%) type II, and 8 (8%) type III. Twenty-eight of 33 acromions with coronal lateral downward sloping had impingement, and all 31 shoulders with medial encroachment had impingement.     

Bioelectrical impedance analysis of body composition in patients with pulmonary emphysema

In this study we utilized bioelectrical impedance analysis (BIA) to compare the body composition of 36 stable pulmonary emphysema (PE) patients with 19 healthy controls. We compared the PE patients and healthy controls in terms of fat-free mass (FFM) and body fat (BF) as percentages of ideal body weight (FFM/IBW, BF/IBW). FFM/IBW and BF/IBW were significantly lower in the PE patients than in the controls (75.0 +/- 9.8% vs. 85.2 +/- 7.3%, p < 0.001 and 11.8 +/- 6.4% vs. 16.7 +/- 7.7%, p < 0.05, respectively). We divided the PE patients into two subgroups according to FFM, then investigated the relationships between FFM and skeletal muscle strength, and between FFM and respiratory muscle strength. In patients with reduced FFM (FFM < 43.5 kg) grip strength as an index of skeletal muscle strength was significantly lower than in patients without reduced FFM (FFM > or = 43.5 kg) (25.7 +/- 7.8 kg vs. 36.2 +/- 7.2 kg, p < 0.005). As indexes of respiratory muscle strength, maximal expiratory pressure (PEmax) and maximal inspiratory pressure (PImax) were lower in the patients with reduced of FFM, but not to a statistically significant degree (49.6 +/- 20.8 cm H2O vs. 58.7 +/- 23.9 cm H2O and 40.5 +/- 19.2 cm H2O vs. 50.2 +/- 22.1 cm H2O, respectively). In the PE patients, FFM correlated closely with vital capacity (r = 0.528, p < 0.001), forced vital capacity (FVC) (r = 0.531, p < 0.001), FEV1.0 (r = 0.554, p < 0.001), FEV1.0/FVC (r = 0.467, p < 0.005), RV/TLC (r = -0.395, p < 0.05), DLco (r = 0.770, p < 0.001), and DLco/VA (r = 0.622, p < 0.001). However no correlation was observed between BF and any of the measures of lung function. The findings of our study suggest that FFM correlates with skeletal muscle strength, respiratory muscle strength and some measures of lung function in patients with PE, and that assessments of body composition are valuable to their clinical management.