Synthesis of two-dimensional IIR digital filters with desired spatial domain specifications and no overflow oscillations

A design technique of two-dimensional (2D) recursive infinite-area impulse response (IIR) digital filters (DFs) which approximates desired spatial-domain specifications and guarantees no overflow oscillations is proposed in this paper. First, it is shown that the balanced approximation is not optimal for l₂ model reduction. From this point of view, a new design technique of 2D separable-denominator (SD) digital filters is studied using reduced-dimensional decomposition and the l₂ model reduction methods based on balanced gains. This result is used as a starting point of a design algorithm for 2D non-separable ND DFs. Second, a design problem of 2D ND DFs is formulated as a nonlinear minimization problem with equality and inequality constraints, and the Broyden-Fletcher-Goldfarb-Shanno algorithm is applied to solve it. Finally, two examples are given to show the effectiveness of the proposed design technique.     

Effects of an aldose reductase inhibitor, SNK-860, on the histopathological changes of retinal tissues in a streptozotocin-induced diabetic rat model

The efficacy of two protocols for the prevention of relapse using Mitomycin-C and alpha-Interferon in 56 patients with surface bladder carcinoma (stages Ta-T1) treated with TUR was compared in a prospective study. Relapse percentages and rates, related to the tumours' presentation characteristics (single, multiple, primary, recurrent), as well as their systemic and local toxicity, were evaluated. The study of statistical significance is made using the squared-chi test, and it is completed with a Fisher's test for groups containing few elements for accuracy. The results show no statistical differences (log rank p = 0.313) between the two groups of endovesical therapy, both confirming to be effective as adjuvant therapy to TUR in surface bladder tumours.     

Zonation of the adrenal cortex. I. Isolation of mitochondria from the zona glomerulosa of the bovine adrenal cortex

Isolation procedures for mitochondria from the zona glomerulosa of the bovine adrenal cortex are described in comparison to those isolated from the zona fasciculo-reticularis. The cristal membranes of mitochondria in the zona glomerulosa in situ are tubular or tubulo-vesicular, whereas those of mitochondria in the zona fasciculo-reticularis in situ are vesicular. When mitochondria are isolated from the former zone, they invariably showed a condensed configuration regardless of isolation media, whereas those isolated from the later zone in a ST medium showed an orthodox configuration. When Ca2+ was added to mitochondria isolated form either zone in an STE medium in the condensed configuration, transition from the condensed to the orthodox configuration took place; the cristel membrane of mitochondria from the zona glomerulosa became tubular or tubulo-vesicular and those of mitochondria from the zona fasciculo-reticularis became vesicular. Purity of mitochondria thus obtained from the zona glomerulosa was examined by electron microscope and marker enzymes. Coupling efficiency of mitochondria was found to be remarkably affected by temperature during the isolation procedures and a choice of substrates.     

Intercellular communication within the rat anterior pituitary gland: VI. Development of gap junctions between folliculo-stellate cells under the influence of ovariectomy and sex steroids in the female rat

BACKGROUND: Farquhar (1957) initially described the folliculo-stellate cells in the rat anterior pituitary gland and found them to be located in groups around follicles throughout the anterior lobe. Soji and his co-workers have published a series of reports concerning cell-to-cell communication in the male rat hypophysis involving folliculo-stellate cells as mediated through a gap junctional network and recorded a reduction in junctional number following castration that was reversed by the administration of testosterone (Soji and Herbert, 1990, Anat. Rec., 226:342-346; Soji et al., 1990, Anat. Rec., 226:337-341). METHODS: Animals were ovariectomized at 10 days of age and separated into three groups: (1) intact control, (2) ovariectomized controls, (3) ovariectomized and given either estradiol, testosterone, or progesterone. On days 10, 20, 30, 40, and 45, the pituitary gland from animals in each group was removed and processed for ultrastructural examination. RESULTS: Gap junctions in the intact control female rats initially appeared between adjacent folliculo-stellate cells on day 20. Their numbers linearly increased until the animals reached the age of 45 days. In contrast, there was a suppression in the number of gap junctions present in the ovariectomized groups and a marked enhancement of the junctions in each of the three steroid-treated groups. CONCLUSIONS: These findings support the observations made in the male rat in which it was found that the development of gap junctions in the anterior pituitary gland of the rat is dependent in part on the presence of sex steroid hormones.     

Microporous coordination polymers of cobalt(II) and manganese(II) 2,6-naphthalenedicarboxylate: preparations, structures and gas sorptive and magnetic properties

Two isostructural coordination polymers M₃(NDC)₃(DMF)₄ (M = Co (1), Mn (2); H₂NDC = 2,6-naphthalenedicarboxylic acid; DMF = N,N′-dimethylformamide) were prepared through conventional and microwave-assisted solvothermal methods. Single crystal X-ray analysis indicated that both complexes crystallized in the monoclinic system with space group C2/c. Powder X-ray diffraction (PXRD) patterns of the bulk samples for the two complexes obtained from microwave-assisted solvothermal syntheses matched well with the simulated ones from the single crystal data as well as the ones prepared by conventional solvothermal method. These microporous cobalt(II) and manganese(II) coordination polymers undergo reversible structural change upon desolvating, giving stable microporous frameworks containing unsaturated metal sites, and resolvating. The desolvated complexes showed different nitrogen gas adsorption capabilities but very close hydrogen adsorption behaviors. Variable-temperature magnetic susceptibilities of 1 and 2 revealed the weak antiferromagnetic coupling between the adjacent metal ions bridged by carboxylate.     

Enantioselective Cyanosilylation of Ketones with Amino Acid/BINAP/Ruthenium(II)‐Lithium Phenoxide Catalyst Systems

Enantioselective reactions of simple ketones, α,α‐ and β,β‐dialkoxy ketones, and α‐alkoxy ketones with trimethylsilyl cyanide catalyzed by the bimetallic systems of amino acid/BINAP/ruthenium(II) complexes and lithium phenoxide have been studied [BINAP=2,2′‐bis(diphenylphosphino)‐1,1′‐binaphthyl]. The Ru(PhGly)₂(BINAP)‐lithium phenoxide system showed high enantioselectivity for the reaction of acetophenone derivatives to afford the cyanated products in up to 90% ee [PhGly=phenylglycinate]. For the cyanosilylation of dialkoxy ketones and α‐alkoxy ketones, the Ru(t‐Leu)₂(BINAP)‐lithium phenoxide system exhibited the best catalyst performance to produce the cyanohydrin derivatives in up to 99% ee and 98% ee, respectively [t‐Leu=tert‐leucinate]. The excellent catalytic activity resulted in complete conversion in the reaction with a substrate‐to‐catalyst molar ratio (S/C) of 10,000 in the best cases.     

Free radical-induced megamitochondria formation and apoptosis

Pathophysiological meaning and the mechanism of the formation of megamitochondria (MG) induced under physiological and pathological conditions remain obscure. We now provide evidence suggesting that the MG formation may be a prerequisite for free radical-mediated apoptosis. MG were detected in primary cultured rat hepatocytes, rat liver cell lines RL-34 and IAR-20 and kidney cell line Cos-1 treated for 22 h with various chemicals known to generate free radicals: hydrazine, chloramphenicol, methyl-glyoxal-bis-guanylhydrazone, indomethacin, H2O2, and erythromycin using a fluorescent dye Mito Tracker Red CMXRos (CMXRos) for confocal laser microscopy and also by electron microscopy. Remarkable elevations of the intracellular level of reactive oxygen species (ROS), monitored by staining of cells with a fluorescent dye carboxy-H2-DCFDA, were detected before MG were formed. Prolongation of the incubation time with various chemicals, specified above, for 36 h or longer has induced distinct structural changes of the cell, which characterize apoptosis: condensation of nuclei, the formation of apoptotic bodies, and the ladder formation. Cells treated with the chemicals for 22 h were arrested in G1 phase, and apoptotic sub-G1 populations then became gradually increased. The membrane potential of MG induced by chloramphenicol detected by CMXRos for flow cytometry was found to be decreased compared to that of mitochondria in control cells. Rates of the generation of H2O2 and O2- from MG isolated from the liver of rats treated with chloramphenicol or hydrazine were found to be lower than those of mitochondria of the liver of control animals. We suggest, based on the present results together with our previous findings, that the formation of MG may be an adaptive process at a subcellular level to unfavorable environments: when cells are exposed to excess amounts of free radicals mitochondria become enlarged decreasing the rate of oxygen consumption. Decreases in the oxygen consumption of MG may result in decreases in the rate of ROS production as shown in the present study. This will at the same time result in decreases in ATP production from MG. If cells are exposed to a large amount of free radicals beyond a certain period of time, lowered intracellular levels of ATP may result in apoptotic changes of the cell.     

Epidemiological study of snoring--a questionnaire survey in factory workers

There has been no epidemiological study of snoring in Japan, and we therefore performed a questionnaire survey (in about 7,000 adult men working at a steel-making factory at the time of the yearly health examination, and investigated the relationship between the severity of snoring and 17 items including age, obesity, family history of snoring, daytime hypersomnolence, hypertension, smoking, alcohol intake and traffic accidents. We classified all the subjects into three groups, no snoring, mild snoring, and severe snoring group. We defined severe snorers as persons who snored loudly in both inspiratory and expiratory phases and those who snored loudly with apnea. We found that aging, obesity, smoking and alcohol intake are risk factors for snoring. Compared with non-snorers, severe snorers were found to have a high incidence of family history of snoring, daytime hypersomnolence, and history of treatment of hypertension. No relationship was found between the severity of snoring and the occurrence of automobile accidents. The proportion of severe snorers over 40 years old with obesity, daytime hypersomnolence and morning headache was 0.25%, representing the group that may have obstructive sleep apnea syndrome. The probable incidence of sleep apnea syndrome in men may be considerably lower in Japan compared with that in either U.S.A. or Europe.     

Steroidogenesis in the zona glomerulosa of the adrenal cortex. II. Distribution of cytochrome P-450 in the zona glomerulosa of the bovine adrenal cortex

Microsomes were obtained from the zona glomerulosa of the bovine adrenal cortex. Contamination of microsomes with other cellular organelles was examined using various marker enzymes and the electron microscope. Distribution of cytochrome P-450 in mitochondria and in microsomes was determined to be 0.73 and 0.32 nmol/mg protein, respectively. The CO difference spectrum was affected not only by the concentration of added deoxycholate but also by the incubation time after addition. Approximately 40-50% of cytochrome P-450 in the samples was converted to cytochrome P-420 within 20-30 sec of incubation with deoxycholate. The content of RNA, phospholipids, and cytochrome b5 in microsomes obtained from the zona glomerulosa is also evaluated in comparison to that in microsomes obtained from the zona fasciculoreticularis.