InP-lnGaAsP planar avalanche photodiodes with self-guard-ring effect

Marked diode characteristics dependence on the distance between p-n junction and heterointerface in double heterojunction InP-InGaAsP planar a.p.d.s is described. In a diode with an optimised configuration, as high as 3000 maximum avalanche gain and less than 3×10?6 A/cm2 dark-current density at 0.9 VB are achieved.     

Image processing based on seeded spontaneous optical pattern formation by optoelectronic feedback

Spontaneous optical pattern formation from an initial seed optical pattern in an optoelectronic system with optical diffractive feedback is investigated experimentally. We demonstrate that the temporal evolution of the spontaneously formed patterns exhibits a contrast enhancement effect, a spatial filtering effect, and filling of vacant space while the surrounding structures are maintained. These effects allow us to perform image processing of natural fringe patterns, i.e., in our experiments, fingerprint patterns. We also demonstrate image processing with defect invariance for fingerprint patterns.     

The relationship of pyridoxine and riboflavin to the nutritional value of polymerized fats

Summary The nutritive value of polymerized fats was compared by feeding them at a 10% level to weanling rats kept on three different basal rations and various vitamin supplements. Autoxidatively or thermally autoxidatively polymerized fats depressed growth, and thermally polymerized fats were toxic to rats. The results indicated that the dietary level of riboflavin and pyridoxine and the manner in which the fats were polymerized had an important bearing on their nutritional value. The protein level also influenced the nutritional value of the oils and, at lower levels, appeared to be related to pyridoxine intake as the growth depression and the toxicity were partially overcome by supplementation of the diet with pyridoxine. Riboflavin apparently aided the animals in coping with autoxidized fat but did not contribute any protective action against thermal polymers. Presented at the American Oil Chemists' Society meeting, Oct. 11–14, 1954. This investigation was supported in part by research grant No. C-1932 from the National Institutes of Health, Department of Health, Education and Welfare.     

Less blood damage in the impeller centrifugal pump: a comparative study with the roller pump in open heart surgery

A centrifugal pump with an impeller (Nikkiso Centrifugal Pump, Model HPM15; Nikkiso Co. Ltd.) was applied to cardiopulmonary bypass (CPB) in 14 patients who underwent elective coronary artery bypass grafting. Serum hemoglobin level, platelet count, and serum beta-thromboglobulin (beta TG) level were measured during CPB. The results were compared with those obtained in a comparative roller pump (RP) group (n = 10). There was no difference in the time on CPB between the NP (109 min) and RP (121 min) groups. The serum beta TG level (ng/ml) was lower in the NP group than in the RP group (obtained 90 min after the initiation of CPB). The plasma-free hemoglobin level also was lower in the NP group than in the RP group (obtained 90 min after the initiation of CPB, 120 min after the initiation of CPB, immediately after the termination of CPB, 3 h after termination of CPB; p < 0.01). There was no significant difference in platelet depletion. The HPM15 pump showed excellent hemodynamic performance with less blood trauma compared with the roller pump in its clinical application to open heart surgery.     

A surface acoustic wave on a ferroelectric layer-structure oxide

As a piezoelectric application of a ferroelectric material of layer-structure type, a surface acoustic wave device using a ceramic Pb_0.15 (NaBi)_0.425Bi₄Ti₄O₁₅, produced by a hot-forging technique is described. The surface acoustic wave on the substrate with the poling axis parallel to the free surface is Blustein-Gulyaev type and its velocity is 2812 m/s.     

Radar cross-section measurement method using a spatial filtering within a near zone

A spatial filtering is a useful method for suppressing unwanted reflection from undesired scatters on radar cross-section (RCS) measurements. Highly accurate RCS measurements for stealth-designed targets are generally performed by using full-scale models. However, it is difficult to carry out a measurement of a large full-scale target, because a vast RCS measurement site which satisfies the far-field criterion without undesired scatters is required. In this paper, we have applied the filtering method to RCS measurements in a near field and investigated the validity of that method by varying the scanning angular span. First, a distribution of scattering sources including undesired scatters is predicted from near-field spherical- or cylindrical-scanning data. Next, undesired scatters are suppressed using the spatial filtering. Finally, RCS values of the test target are calculated by taking the Fourier transform of the filtered scattering source distribution. Using electromagnetic simulations, we have validated the RCS measurement method by comparing predicted RCS with reference data as far-field RCS of the test target. As a result, predicted RCS profiles closely matched with reference data. In conclusion, the proposed method is useful for RCS measurements within the unsuitable near zone. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Alkoxyresorufin O-dealkylase assay using a rat hepatocyte spheroid microarray

Hepatocyte multicellular aggregates (spheroids), which maintain high expression of liver functions, have been advocated as a useful culture technique for various cell-based assays. In this study, we investigated the drug metabolic function of a hepatocyte spheroid microarray (HSM) chip, which contained an array of 672 spheroids of primary rat hepatocytes within a 100-mm² region in the center of a poly(methylmethacrylate) plate (24 × 24 mm) and used an alkoxyresorufin (ethoxy-, methoxy-, pentoxy- and benzyloxyresorufin) O-dealkylase assay system. Ethoxyresorufin O-dealkylase (EROD) activity of the HSM chip initiated by 3-methylcholanthrene (3-MC), an inducer of cytochrome P450 enzymes, was 5- to 10-fold higher than that of monolayer hepatocytes, with activity being maintained for at least 2 weeks. We also demonstrated that 3-MC induced EROD, methoxyresorufin O-dealkylase (MROD) and benzyloxyresorufin O-dealkylase (BROD) activities in the HSM chip, while sodium phenobarbital (P450 inducer) induced pentoxyresorufin O-dealkylase (PROD), BROD, EROD and MROD activities. Induction of these activities was confirmed by increased gene expression of the related P450 enzymes. These results showed that the HSM chip had a good response to P450 inducers and that function was maintained for long periods of time. The HSM chip therefore may be a promising cellular platform for drug metabolic assays using hepatocytes.     

Angiotensin I-Converting Enzyme Inhibitory Effect of Chinese Soypaste Along Fermentation and Ripening: Contribution of Early Soybean Protein Borne Peptides and Late Maillard Reaction Products

Angiotensin I-converting enzyme inhibitory effect of Chinese soypaste was investigated during 4-month fermentation and ripening. This effect increased significantly at early stage and reached a plateau until the end of ripening, with an IC₅₀ value of 0.436 mg/mL for the final product. Peptide and reducing sugar contents increased drastically during early fermentation and declined afterward. Maillard reaction took place continuously as indicated by consistent accumulation of precursor, intermediate, and final Maillard reaction products monitored by fluorescence, ultraviolet-absorbance and absorbance at 420 nm, respectively. During early fermentation, peptides were principal compounds responsible for the angiotensin I-converting enzyme inhibitory effect. During late ripening, angiotensin I-converting enzyme inhibition by Maillard reaction products could compensate for the loss of the effect caused by the utilization of peptides, and enable the total effect to remain at a good and steady level, suggesting an indispensable contribution of Maillard reaction products to angiotensin I-converting enzyme inhibitory effect of soypaste, particularly in products with prolonged maturation.