Partial properties of four glycosidases in normal human lens and variations in their enzyme activities during aging and with the advance of lens coloration

This paper reports the active glycosidases in normal human lenses and their partial properties. In addition, variations in their enzyme activities during aging and with the advance of lens coloration were also examined. Five glycosidases, alpha-glucosidase, beta-D-glucuronidase, N-acetyl-beta-D-glucosaminidase, beta-D-cellobiosidase, and alpha-L-fucosidase, were detected as active glycosidases in the normal human lens. However, the activity of beta-D-cellobiosidase was considerably low as compared to the other four glycosidases. Thus, this enzyme was omitted from this study. The four glycosidases, alpha-D-glucosidase, beta-D-glucuronidase, N-acetyl-beta-D-glucosaminidase, and alpha-L-fucosidase, showed that their enzyme activities fell abruptly between the ages of 40 and 50. Furthermore, the Km values of their enzymes exhibited some variability during aging. Namely, the Km values of their enzymes indicated the lowest value between the 40 age group and 50 age group, suggesting that the substrate affinity became the strongest at these age groups. Then, variations in enzyme activity with the advance of lens coloration were examined. In each cases, the specific activity of detectable glycosidases in color lenses, white to brown, decreased. In particular, the specific activity of enzymes in the brown lens was very low, indicating that glycosidases in the brown lens may scarcely display their enzyme activities.     

Feature extraction of AR as a performance index for load frequency controls of interconnected power systems

Recently, the evaluation of control performances of interconnected power systems has become an important issue with respect to individual load frequency controls. Several performance measures are in practical use such as Area Control Error (ACE), Mutual Aid Criterion (MAC), and Control Performance Standard (CPS). Area Requirement (AR) is an alternative expression for ACE, where AR=?ACE. However, the characteristics of these indices have not been sufficiently studied as far as the authors know. In particular, this is the case for their dynamic behavior against random load disturbances. This paper investigates the performance index, AR, through analysis of two‐area systems. Major dynamic elements of interconnected systems affecting the frequency are taken into account to investigate responses of the system against load disturbances. The analysis shows that, when new systems are interconnected, the smaller system tends to require more effort of control against load disturbances to keep the same value of the performance indices. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 154(1): 20–28, 2006; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20233     

Some unusual responses of astrocytes to ghost tangles in a long duration case of juvenile Alzheimer''s disease: an electron microscopic study

Clavulanic acid (CA) was produced by Streptomyces clavuligerus in medium containing glycerol and soy meal or soy meal extract. With regard to growth and CA productivity, the microorganism showed significant differences if solid soy meal as such or its extract were applied as the major nitrogen source. If the extract is used, growth and CA production take place simultaneously and in the stationary phase the CA concentration is stagnant or reduces. If soy meal is used, growth is threefold faster and CA is only generated in the stationary phase. In the case of using the soy meal extract, the decrease of the CA concentration is mainly due to decomposition or re-metabolisation of CA in the presence of the microorganism. This conclusion is supported by in vivo and in vitro data on CA decomposition.     

Thickness dependence of structural and ferroelectric properties of sol-gel Pb(Zr0.56Ti0.44)0.90(Mg1/3Nb2/3)0.10O3 films

Sol-gel Pb(Zr_0.56Ti_0.44)_0.90(Mg_1/3Nb_2/3)_0.10O₃ (PZT-PMN) films were prepared onto the Ti/Pt/Ti bottom electrode by multilayer spin coating. The film thickness ranged from 0.22 to 0.88 μm. The Pt top electrodes were deposited on the PZT-PMN films by DC sputtering. The structural and ferroelectric properties of PZT-PMN films were investigated as a function of film thickness by X-ray diffraction (XRD), scanning electron microscopy (SEM), cross-sectional transmission electron microscopy (XTEM), and by measuring the relative permittivity. The film retains the tetragonal perovskite structure with the [111] and [100] preferred orientations perpendicular to the film surface independent of film thickness. The [100] texture increases with increasing film thickness although the [111] texture is always predominant. The film consists of columnar grains. The average grain size is nearly independent of film thickness. The surface layer containing fine grains about 30 nm in diameter is induced on the top of the film. As the film thickness exceeds 0.44 μm, the number of the fine grains decreases remarkably. The crystalline interface layer about 10 nm thick is formed between the film and the bottom electrode. This interface layer is composed of Pt, Pb, Zr, Ti and O, while it is rich in Ti and deficient in Pb and O as compared with the inside of the film. The measured relative permittivity of the film increases with increasing film thickness, following the low permittivity interface model. On the basis of this model, the relative permittivity is estimated to be 3200 for the intrinsic PZT-PMN film, 750 for the surface layer and 50 for the interface layer.     

Brief note—A criterion for unstable elastic-plastic brittle fracture based on more realistic model under plane stress

A criterion for unstable elastic-plastic brittle fracture under plane stress was previously proposed based on energy balance considerations, in which the plastic work term was used based on Dugdale model of plastic zone pattern. The realistic pattern, however, of the plastic zone is far from a Dugdale model. Therefore, in this article, a more realistic pattern is used.As a result, a more realistic criterion for unstable elastic-plastic brittle fracture has been obtained. In this new criterion, +p appears in place of the material surface energy term in the previous criterion, where p is the plastic work term corresponding to the excess plastic zone pattern extending in the direction perpendicular to the crack propagation direction beyond over the boundary of Dugdale model.

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Zusammenfassung Man hatte eine Kennzeichnung für den unstabilen elasto-plastischen Sprödbruch unter planer Beanspruchung vorgeschlagen, welche auf Energiebilanzüberlegungen beruhte, wobei das die plastische Arbeit beschreibende Glied auf dem Dugdale-Modell für plastische Verformungszonen begründet war.Der wirkliche Vorgang im plastischen Bereich ist jedoch weft vom Dugdale-Modell entferm. Deshalb wird im vorliegenden Bericht von realistischeren Vorstellungen ausgegangen.Hierbei ergibt sich eine wirklichkeitsgetreuere Kennzeichnung des unstabilen elasto-plastischen Sprödbruchs. In diesem neuen Ausdruck erscheint die Summe +p an Stelle der Materialoberflächenenergie y in dem früheren Kriterium, wobei p die plastische Verformungsarbeit für die plastischen Bereiche darstellt, welche senkrecht zur RiBfortpflanzungsrichtung, jenseits der vom Dugdale-Modell vorgesehenen Grenze liegen.

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Résumé On a précédemment proposé un critère, basé sur des considérations d'équilibre énergétique, pour la rupture fragile en conditions élasto-plastique et sous état plan de tension. Dans ce critère, on faisait appel au travail plastique, sur la base du modèle du Dugdale relatif aux configurations des zones de déformation plastique.La configuration réelle de ces zones est, toutefois, assez différente de celle du modèle de Dugdale. On a donc consideré, dans ce mémoire, une configuration plus réaliste.On a ainsi obtenu un critere, plus réaliste, de la rupture fragile élasto-plastique. Dans celui-ci,l'ènergie de surface du précédent critère a été remplacé par un terme +p, où p représente le travail de déformation plastique correspondant aux zones plastiques qui s'étendent, perpendiculairement à l'axe de propagation de la fissure, au-delà de la limite prévue par Dugdale.

     

Association analysis of the SHC1 gene locus with longevity in the Japanese population

The SHC1 gene encodes a signaling and transforming protein that has been implicated in the aging process in worms and mammals. In this study we examined 230 Japanese centenarians and 180 healthy younger controls and looked at the SHC1 locus as a candidate region that may be associated with longevity. We identified 12 single nucleotide polymorphisms (SNPs) within a 10-kb region encompassing the entire SHC1 gene from the DNA of 30 centenarians and 24 healthy younger controls. Five SNPs, including three nonsynonymous sites, lay within coding elements, six were located within introns, and one was in the 3' untranslated region. All of these SNPs were relatively rare, with a minor allele frequency of less than 5% in our subjects. A pairwise linkage disequilibrium analysis using the r2 statistic showed that two of the SNP pairs are in tight linkage disequilibrium at this locus. We investigated the possible association of SHC1 with longevity using association analyses with allelotypes and haplotypes but found that the SNPs identified in SHC1 had no impact on longevity for Japanese centenarians.     

An investigation on debris bed self-leveling behavior with non-spherical particles

Studies on debris bed self-leveling behavior with non-spherical particles are crucial in the assessment of actual leveling behavior that could occur in core disruptive accident of sodium-cooled fast reactors. Although in our previous publications, a simple empirical model (based model), with its wide applicability confirmed over various experimental conditions, has been successfully advanced to predict the transient leveling behavior, up until now this model is restricted to calculations of debris bed of spherical particles. Focusing on this aspect, in this study a series of experiments using non-spherical particles was performed within a recently developed comparatively larger scale experimental facility. Based on the knowledge and data obtained, an extension scheme was suggested with the intention to extend the base model to cover the particle-shape influence. The proposed scheme principally consists of two parts – with one part for correcting the terminal velocity of a single non-spherical particle, which is the key parameter in our base model, and the other for representing the additional particle–particle interactions caused by the shape-related parameters. Through detailed analyses, it is found that by coupling this scheme, good agreement between experimental and predicted results can be achieved for both spherical and non-spherical particles given current range of experimental conditions.     

Study of flow instability in off design operation of a multistage centrifugal pump

In recent years, attempts have been made to make multistage centrifugal pumps smaller in size and more efficient. However, such designs are known to cause positive-slope phenomena in the Q-H curve, especially under low-flow conditions. These phenomena, which have thus far been studied experimentally and numerically, stem from flow instability in the pump. However, their mechanisms have not yet been clarified because it depends on various parameters. In this study, we focused on diffuser rotating stall, observed in positive Q-H characteristics. This study elucidates the mechanism of positive-slope generation through experimental results and two-dimensional numerical analysis.     

Dose-dependent selective cytotoxicity of extracts from marine green alga, Cladophoropsis vaucheriaeformis, against mouse leukemia L1210 cells

The cases of four children who presented with respiratory distress unresponsive to bronchodilator treatment and who were subsequently diagnosed with severe anemia were retrospectively reviewed from charts at a children's hospital with 110 beds and an emergency department census of 32,000 per year. The four children, age range 11 months to 2 years, each initially presented with tachypnea. Three had wheezing, three were pale, and each received outpatient bronchodilator treatment. Three to 4 days later, each patient was hospitalized for continued respiratory distress. Each child was pale, and hemoglobin levels ranged from 2.5 to 5.2 g/dL. In three children, respiratory distress resolved with blood transfusions. Final diagnoses were transient erythroblastopenia of childhood in 2, acute lymphoblastic leukemia in 1, and iron deficiency anemia in 1. Severe anemia is a known cause of respiratory distress. These cases remind the clinician to consider severe anemia in children who are tachypneic, pale, and unresponsive to treatment of respiratory disorders.