Fabrication of a miniature-size pyramidal-shape diamond fieldemitter array

A miniature-size pyramidal-shape diamond field emitter array has been fabricated using the mold technique. The tip radius of each pyramid was found to be less than 2000 Å from SEM observation and the fabricated array was identified as diamond from the results of AES and Raman spectroscopy. The array was placed in a high vacuum pumping system with the basic pressure of 10^-7 Torr, and the emission property was measured using a Au ball anode with 100 μm in diameter. The distance between the anode and the array was set up to 100 μm throughout the measurements. As a result, the emission current of 1×10^-6 A was observed at the applied voltage of 2400 V     

Lymphocyte blastogenesis in hairless dogs following stimulation by various mitogens

Lymphocyte blastogenesis in hairless descendants of Mexican hairless dogs was examined using the following mitogens: phytohemagglutinin (PHA-M), Concanavalin A (Con A), lipopolysaccharide (LPS) and pokeweed mitogen (PWM). Blastogenetic responses to these mitogens were measured by glucose consumption test (GCT) and compared with those of haired beagle dogs. The response to PHA-M was significantly less in the hairless dogs than in the beagles. No significant differences in the responses to Con A, PWM and LPS were recognized. These results indicated T-cell dysfunction in the hairless dogs, coinciding with our previous work showing reduction of the delayed-type hypersensitivity reaction and early degeneration of the thymus.     

Enzymatic synthesis, isolation, and analysis of novel alpha- and beta-galactosyl-cycloisomalto-octaoses

Novel branched cycloisomalto-octaoses (CI8s) were enzymatically synthesized by transgalactosylation with alpha-galactosidase from coffee bean and beta-galactosidase preparations from Penicillium multicolor and Bacillus circulans, using melibiose and lactose as donor substrates, and CI8 which is a cyclic homogeneous oligosaccharide composed of eight glucose units bound by alpha-(1-->6)-linkages, as an acceptor. alpha-Galactosyl-CI8s and beta-galactosyl-CI8s obtained were isolated and purified by HPLC. Their structures were elucidated by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDITOFMS) and NMR spectroscopy.     

Correlation between bone metabolic markers and bone scan in prostatic cancer

PURPOSE: We examined the correlation between bone metabolic markers and bone scintigraphy in prostatic cancer. MATERIALS AND METHODS: Osteoblastic and osteoclastic markers, prostate specific antigen (PSA) and bone scans were investigated in 83 specimens from 70 patients with prostatic cancer, including 32 with and 38 without bone metastasis. RESULTS: All markers except for osteocalcin were significantly greater in patients with than without bone metastasis. Pyridinoline cross-linked carboxyterminal telopeptide, an osteoclastic marker, reflected the extent of bone metastasis more accurately than PSA and other bone markers. CONCLUSIONS: Pyridinoline cross-linked carboxyterminal telopeptide might assist PSA and bone scintigraphy in monitoring metastatic bone activity of prostatic cancer.     

Combustion Synthesis of Silicon Carbide in Nitrogen Atmosphere

Fine SiC powders were synthesized by burning the mixed reactionts Si and C in a nitrogen atmosphere of 3 to 10 MPa. The exothermic synthesis reaction propagated spontaneously after igniting the reactants at room temperature. The SiC powders obtained had a uniform size distribution of about 0.2 μm. The combustion velocity was 0.8 to 1.5 mm / s. The maximum temperature measured at the reaction was 2500 K, which was higher than the adiabatic combustion temperature of SiC, but slightly lower than the decomposition temperature of Si₃N₄ under nitrogen pressure.     

Oxidative decomposition of cholesterol in fish products

Cholesterol oxides in fish products popular in Japan, including salted and dried, boiled and dried and smoked products, were qualitatively and quantitatively determined as trimethylsilyl ether derivatives by gas-liquid chromatography and mass spectrometry. The level of total cholesterol oxides ranged widely between 8.3 ppm in boiled and dried shrimp and 188.0 ppm in boiled and dried anchovy. 7β-Hydroxycholesterol and 7-ketocholesterol were the most prominent oxidative decomposition products of cholesterol. The levels of epimeric epoxides, cholestane triol and 25-hydroxycholesterol were relatively low. To elucidate a mechanism of cholesterol oxidation proceeding during fish processing and subsequent preservation, four model systems, consisting of a mixture of purified cod liver triglycerides plus cholesterol, of a mixture of authentic triolein plus cholesterol, of triolein alone and of cholesterol alone, were stored separately at 25°C in dry air for up to 104 d. The residual fatty acids of the triglycerides, and the cholesterol oxides produced, were recovered and determined. Oxygen uptake remained almost unchanged for the mixture of triolein plus cholesterol. No detectable amount of cholesterol oxides was produced, and the fatty acid content of the residual oleic acid, measured by an internal standard, remained almost unchanged. For the mixture of cod liver triglycerides plus cholesterol, a remarkable increase in oxygen uptake was observed. A continuous increase in the amount of cholesterol oxides was observed, accompanied by a remarkable concurrent decrease in polyunsaturated fatty acid residues, as well as of the oleic acid naturally present. These results strongly suggest that cholesterol oxidation in fish products proceeds in conjunction with oxidative decomposition of the coexisting polyunsaturated fatty acids of fish oils.