An analysis of bearingless AC motors

Several types of AC bearingless motors are proposed. These bearingless motors have conventional four-pole stator windings and additional two-pole windings, whose currents produce radial forces acting on the rotor. General expressions of the machine inductances and radial forces are derived for the cylindrical rotor and salient-pole motors. No-load characteristics of laboratory squirrel-cage induction and reluctance-type synchronous bearingless motors are provided. The test motors were successfully driven by the control circuits     

Inherently decoupled magnetic suspension in homopolar-typebearingless motors

The authors have proposed bearingless motors, that is, magnetic bearings combined with motors in the same stator. It is possible to reduce their shaft length compared with a conventional motor with magnetic bearings, and to achieve higher rotational speed. Bearingless motors generate radial force by adding n ± 2-pole flux on n-pole motor flux to make the flux distribution unbalanced. Several types of bearingless motors have already been proposed, and most of them require variations of motor flux to be taken into account to maintain stable radial position control. In this paper, homopolar-type bearingless motors are proposed and their radial force is analyzed. The rotor of a homopolar motor has two cores with salient poles, and each core is magnetized in a single pole. The important characteristics that the radial force does not vary in accordance with the rotor angle or the motor torque current are derived from analysis. It is confirmed by experiments that the radial position can be controlled nearly independently from the rotational angle and torque     

An egg‐shaped diagram and its discrepancies in switched reluctance machines

Recently, switched reluctance motors have attracted attention from industries. It is a common practice to develop several test machines for performance evaluation. One way to make a comparison among several test machines is to draw an efficiency map in a speed and torque plane, but this is rather complicated. For an easy comparison, a machine parameter measurement with an egg‐shaped diagram has been proposed by the authors. In this method, it is possible to measure an inductance ratio, which indicates the saliency of switched reluctance machines. In this paper, a calculation of tolerance between theoretical egg‐shaped curves and measured powers is proposed. It is found that the tolerances are within 4% as a result of several test machines. Although discrepancies in instantaneous current waveforms and voltage phase angles are seen, the obtained machine parameters indicate an exact relation between input power and required apparent power. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 152(1): 61–71, 2005; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10286     

The invasion potentials of human biliary tract carcinoma cell lines: correlation between invasiveness and morphologic characteristics

The abilities of 9 kinds of human biliary tract carcinoma cell lines to invade through basement membrane or type I collagen were examined using an in vitro invasion assay system. The correlations between invasiveness and morphologic characteristics of the carcinoma cells in 3 dimensional collagen gel were also examined. most of the biliary tract carcinoma cell lines kept the abilities of glandular differentiation and basement membrane formation of the original tumor. Their invasiveness, however, correlated with the degree of in vitro morphologic differentiation regardless of their original morphology.     

Biochemical and immunochemical study of seven families with 3-ketothiolase deficiency: diagnosis of heterozygotes using immunochemical determination of the ratio of mitochondrial acetoacetyl-CoA thiolase and 3-ketoacyl-CoA thiolase proteins

The possibility of identifying heterozygotes of 3-ketothiolase deficiency, an inborn error of metabolism caused by a defect of mitochondrial acetoacetyl-CoA thiolase (T2), was tested in seven unrelated families by using enzymatic assay of thiolase activity and immunoblot analysis. The ratio of acetoacetyl-CoA thiolase activities, in the presence and absence of K+ ion (+K/-K ratio), in fibroblasts from 15 normal controls was around 2.0 (1.8 to 2.4), whereas the +K/-K ratio in eight patients was always 1.0. The ratio for the 13 obligate carriers ranged from 1.4 to 1.9, causing a minor overlap with control. Identification of heterozygote cells by immunoblot analysis, using anti-T2 antibody alone as a probe, was difficult, as previously reported. We therefore carried out immunoblot analysis, using as probes a mixture of anti-T2 antibody and the antibody against mitochondrial 3-ketoacyl-CoA thiolase (T1), another mitochondrial thiolase, and determined the ratio of the intensities of the T2 and T1 bands (T2/T1 ratio) using a densitometer. When the T2/T1 ratio was calculated, there was no overlap between the heterozygotes and normal controls. Hence, the heterozygotes can be unambiguously identified using this method. The thiolase activities and T2/T1 proteins in immunoblotting were detectable in peripheral lymphocytes, rectal mucosa, amniocytes, and liver. Thus, the postnatal diagnosis of 3-ketothiolase deficiency can be readily made using lymphocytes or rectal mucosa. The applicability of these methods in amniocytes indicates that prenatal diagnosis of this disease should be possible.     

Efficacy of heat-killed <Emphasis Type="Italic">Lactococcus lactis</Emphasis> JCM 5805 on immunity and fatigue during consecutive high intensity exercise in male athletes: a randomized,placebo-controlled,double-blinded trial

Background

Lactococcus lactis JCM 5805 (LC-Plasma) is a unique lactic acid bacteria (LAB) which activates plasmacytoid dendritic cells (pDC). We aimed to evaluate the effect of LC-Plasma on dendritic cell (DC) activity and subjective indices of upper respiratory tract infections (URTI) and fatigue in athletes under high intensity exercise.

Methods

We conducted a randomized, placebo-controlled, double-blinded trial. Fifty-one male subjects belonging to a university sports club were randomized into placebo (n?=?25) and LC-Plasma (n?=?26) groups. Individuals ingested placebo capsules containing cornstarch or LC-Plasma capsules containing 100 billion cells of heat-killed LC-Plasma per day for 13 days. During the intervention period, subjects performed high intensity exercise according to their sports club training regime. Blood and saliva sampling were obtained at days 1 and 14, and physical conditions were recorded in a diary. We investigated expression of maturation markers on DCs, muscle damage and stress markers and used student’s t test adjusted by Bonferoni’s method for multiple comparison between groups. These data were presented as mean?±?SD. We also investigated cumulative days of symptoms regarding infections and fatigue and used Chi-square test for comparison between groups. These data were presented as cumulative number.

Results

CD86 as maturation marker on pDC was significantly increased in the LC-Plasma group at day 14 (Placebo: 296?±?70 vs. LC-Plasma: 365?±?115; Mean Fluorescent Intensity; p?=?0.013). Cumulative days of URTI were significantly lower in the LC-Plasma group (Placebo: URTI positive 56, URTI negative 256 vs. LC-Plasma: URTI positive 39, URTI negative 299; days; p?=?0.028) and symptoms like sneeze or running nose were significantly lower in the LC-Plasma group (Placebo: Symptom positive 52, Symptom negative 258, vs. LC-Plasma: Symptom positive 36, Symptom negative 301; days; p?=?0.032). Moreover, the cumulative days of fatigue were significantly fewer in the LC-Plasma group (Placebo: Symptom positive 128, Symptom negative 182, vs. LC-Plasma: Symptom positive 110, Symptom negative 225; days; p?=?0.032). Markers of muscle damage and stress markers were not significantly different between groups.

Conclusion

We consider that heat-killed LC-Plasma supplementation relieves morbidity and symptoms of URTI via activation of pDC and decreases fatigue accumulation during consecutive high intensity exercise in athletes. However, LC-Plasma ingestion did not affect markers of muscle damage and stress.

Trial registration

UMIN-CTR, UMIN000020372. Registered 28 December 2015.

     

An analysis of the intracerebral ability to eliminate a nitroxide radical in the rat after administration of idebenone by anin vivo rapid scan electron spin resonance spectrometer

Electron spin resonance (ESR) measurements after intracerebroventricular injection of a nitroxide radical were carried out in rats (n=6) that received oral idebenone for 2 weeks and in control rats (n=5), using anin vivo rapid scan ESR spectrometer. The half-life of nitroxide, which was estimated from the change in the peak height (M=+1) of the ESR signals from the head, was used as a marker for the elimination of the nitroxide radical. The half-life in the rats treated with idebenone was significantly shorter than it was in the controls (p<0.05). This finding indicates that the treatment with idebenone can enhance the intracerebral-eliminating ability of the nitroxide radical.