Effect of High-Voltage Screening on Strength Distribution for Titanium Dioxide Ceramics

A screening field at or below which 30% of TiO₂ ceramic samples break electrically was applied to the samples. After high-voltage screening, the surviving samples were subjected to mechanical strength measurement and the resulting strength distribution was compared to the original distribution. The effect of high-voltage screening and the correlation between mechanical and dielectric strength are discussed. There is a correlation between mechanical and dielectric strengths with a correlation coefficient of 0.77, which indicates the validity of high-voltage screening.     

Effect of correction function on image characteristics of Positologica: a positron CT device for the head

The effects of correction function on image characteristics were studied experimentally for a positron CT device Positologica. Correction functions were obtained by smoothing the Shepp and Logan function by convolution of Gaussian functions. Signal-to-noise ratio (SNR) and spatial resolution were measured for phantoms and related to the magnitude of smoothing. The relation between SNR and spatial resolution is also discussed. Some suggestions are made to indicate how to select correction functions for clinical images. A flow of data processing for Positologica is described together with an outline of its hardware.     

Experimental cerebral vasospasm after subarachnoid hemorrhage: development and degree of vasospasm

Vasospasm of the basilar artery in 57 cats was induced by application of fresh blood, or a blood and cerebrospinal fluid (CSF) mixture incubated at 37 degrees C for 2 to 16 days. In animals treated with fresh blood or mixtures incubated for over 15 days, the severity of induced vasoconstriction is slight and duration short. Mixtures incubated 5 to 10 days induced severe and prolonged vasoconstriction. This incubation period for blood and CSF mixtures inducing severe vasospasm coincides with the developmental period of vasospasm after the onset of subarachnoid hemorrhage in our clinical experience. The prolongation of severe vasoconstriction induced by mixtures incubated for 7 days with clotted components is definitely greater than one induced by a mixture without clotted components. This experimental study suggests the existence of a vasospasmogenic substance in the blood in the subarachnoid space. Activity begins about 3 days after subarachnoid hemorrhage, increases strongly at 5 to 10 days, and disappears after 15 days.     

SEM studies of electrolytic manganese dioxide

Manganese dioxide is deposited on the anode from MnSO₄ solution (95°C) containing H₂SO₄ and another acid, such as HCl and HNO₃. X-ray diffraction reveals a γ-MnO₂ structure. Addition of 0.1 M HCl or HNO₃ to the MnSO₄ solution containing H₂SO₄ results in lower cell voltage. Scanning electron micrographs of these surface deposits show that, in the case of a MnSO₄ + H₂SO₄ solution, a so-called fibrous microstructure was observed and crystal size became greater when the hydrochloric acid was added up to about 0.1 M.     

P–T Boundary of α-PbO2 Type and Baddeleyite Type High-Pressure Phases of Titanium Dioxide

In situ X-ray diffraction experiments have been carried out under high pressures up to 18 GPa and temperatures up to 950°C to determine the stable regions of the α-PbO₂ type and baddeleyite type high-pressure phases of TiO₂. Observation of the transitions among the three phases, including the rutile phase, along various paths on the P–T diagram results in the phase boundary equation, T (°C) = 188.7 P (GPa) - 2192.5, separating the α-PbO₂ and baddeleyite phases.     

Immunohistochemical study of monoclonal antibody against gamma-seminoprotein in the prostatic tissues. A significant correlation between the degree of staining and the histological grade of adenocarcinoma of the prostate

The tissues consisted of adenocarcinoma of the prostate were examined by immunohistochemical study with monoclonal antibody (43-21-1-1) against gamma-seminoprotein (gamma Sm)2). The degree of staining regarding any correlation with the histological grade was evaluated. The prostatic tissues were obtained by transurethral resection or by fine needle biopsy from untreated 38 patients. The avidin-biotin peroxidase complex technique was used to stain on 3 microns-sections of 10% formalin fixed, paraffin embedded tissue. In addition, immunohistochemical staining with the commercialized antibodies to prostate-specific antigen (PSA; polyclonal, DAKO) and to prostatic acid phosphatase (PAP; polyclonal, DAKO) was done simultaneously for a comparative study. The degree of immunoperoxidase stain was classified into two categories, namely location and pattern, and was graded from 0 to 3, respectively. The product of the degree of location and the degree of pattern was noted as the total score. The mean of score was calculated in each histological grade. Then the means of total scores were compared and evaluated as having any statistical difference by Student's t test among 3 histological grades as well as among 3 primary antibodies used in this study. When the monoclonal antibody to gamma-Sm was used for immunoperoxidase staining, the means of total scores and the rates of negative reactions (% Negative) in 3 histological grades were 6.8 +/- 1.8 (M +/- SD) and 0% in well (N = 9), 4.4 +/- 2.4 and 14% in moderately (N = 22), and 1.8 +/- 2.3 and 54% in poorly differentiated lesions (N = 11), respectively. There were statistically significant differences (P < 0.05) among 3 histological grades.(ABSTRACT TRUNCATED AT 250 WORDS)