Effect of Milling on Slip Casting of Partially Stabilized Zirconia

Specimens of partially stabilized zirconia were slip cast from aqueous suspensions and sintered at 1500°C for 3 h. The relative density of the cast specimens and the firing shrinkage of the sintered specimens depend on the milling time for the suspension. Vickers hardness and K_IC values of 11.46±s0.07 GN/m² and 6.10 ±0.04 MN.m^3/2, respectively, were obtained for all sintered specimens. The dispersion of the suspension is important in increasing the relative density of the cast specimens.     

A transceiver PIC for bidirectional optical communication fabricated by bandgap energy controlled selective MOVPE

A transceiver PIC consisting of a DFB-LD, a receiver PD and a Y-shaped branch waveguides is realized by in-plane bandgap energy controlled selective MOVPE. Both active and passive core layers are formed in one step selective growth, and complicated fabrication procedure is no longer required. More than 1 mW fiber coupled power and 7 GHz receiver bandwidth are obtained. The modulation and detection operations at 500 Mb/s are successfully demonstrated.     

Efficacy of interferons in treating children with chronic hepatitis C

Twenty-two children with chronic hepatitis serologically positive for hepatitis C virus (HCV) were treated with interferon-alpha (IFN-alpha). Liver biopsy showed chronic active hepatitis in 13 and chronic persistent hepatitis in 9 patients. A sustained clearance of HCV was observed in 8/22 children 12 months after the administration of IFN-alpha for 26 weeks, associated with normalization of HCV core antibody. Of these eight patients six had HCV genotype III and two HCV genotype II or IV. Hepatitis relapsed in seven other patients after completion of IFN-alpha with an increase in HCV core antibody titre, five with HCV genotype II, and two with HCV genotype III or IV. A second course of IFN-alpha suppressed the reactivation of HCV in all seven patients. Three of seven responders who relapsed after the first course remained negative for HCV RNA 12 months after their second course of IFN-alpha. However, the remaining four patients with HCV genotype II again relapsed after completing their second course of IFN-alpha. Seven children with the HCV genotype II resistant to IFN, including 8 weeks of IFN-beta administration, and showed no significant reduction in HCV core antibody titre. CONCLUSION: The genotype of HCV (III) and a reduction in the core antibody titre appear to be useful parameters for predicting the response to IFN-alpha therapy.     

Percutaneous lumbar nucleotomy

The nature of the events whereby the reactive intermediates resulting from the bioactivation of bromobenzene and furosemide induce hepatotoxicity is unknown. To examine a role for disturbances in intracellular calcium homeostasis, secondary to a depletion in cellular reduced glutathione (GSH) and reduced protein thiols (PSHs), isolated mouse hepatocytes were exposed to cytotoxic concentrations of bromobenzene or furosemide. Cytosolic calcium concentration, as well as thiol status, was determined. The incubation of hepatocytes with 3.0 mM bromobenzene, and subsequent additions (1.2 mM) of the agent every hour, resulted in significant GSH depletion. The loss of plasma membrane integrity at 1.5 h preceded both a rise in the cytosolic Ca2+ concentration and depletion of total PSH content. Furosemide (1.0 mM) produced a 70% depletion in cellular GSH content in isolated hepatocytes. The initiation of cell damage occurred concurrently with both a rise in the cytosolic Ca2+ concentration and a depletion of total PSH content 4 h following furosemide addition. Since the increase in cytosolic Ca2+ did not precede cytotoxicity, these results do not support an initiating role for Ca2+ deregulation in bromobenzene and furosemide hepatotoxicities. In addition, depletion of PSH content did not correlate with bromobenzene- or furosemide-induced cytotoxicity.     

Polyacene capacitors

We fabricated two types of polyacene capacitor with extremely stable polyacenic semiconductor (PAS) as the positive and negative electrodes. The first one is a coin-type PAS capacitor (six different sizes), which possesses large capacity with high reliability. Its capacity is much larger than that of the conventional electric double-layer capacitor which uses activated carbon as electrode. PAS capacitor can maintain more than 70% of the initial capacity even after 100 000 cycles. Moreover, this capacitor can be charged and discharged in a few minutes as well as at low rate. The second one is a cylinder-type PAS capacitor (diameter: 18 mm, height: 65 mm) which shows high capacity of 100 F and can discharge at the extremely high rate of 80 C. The coin-type PAS capacitor is currently used for memory back-up of electrical and communication equipment, and the cylinder-type is considered to be useful as power back-up for starting drive parts of electric equipment which needs high power density.     

Transverse colonic stenosis

A 3-year child presented with episodic lower abdominal pain; during the eighth attack, a mass was palpable in the left upper quadrant, and a barium enema revealed a stenotic area in the transverse colon. This was resected and an uneventful postoperative course followed. Subsequently, the child has remained symptom-free. instruments are no longer in use.     

Electrochemical reduction of nitrate on Pt(S)[n(1 1 1) × (1 1 1)] electrodes in perchloric acid solution

The electrochemical reduction of nitrate ion was studied by cyclic voltammetry on Pt(1 1 1) and [n(1 1 1) × (1 1 1)] stepped Pt surfaces, where n (=14, 10, 7, 6, 5, 4, 3, 2) is the number of terrace atoms, in 0.1 M HClO₄ + 10 mM KNO₃. The electrocatalytic nitrate reduction was found to hardly proceed on Pt(1 1 1) in the hydrogen adsorption region, while the electrocatalytic activity was improved with the increase in the step density. Inactivation was observed in the presence of adsorbed hydrogen or nitrate-derived reduced adsorbate, i.e. adsorbed NO, on (1 1 1) step sites. It was, therefore, concluded that the electrocatalytically active NO₃⁻ species does not adsorb on the (1 1 1) terraces but on the (1 1 1) monoatomic steps. The nitrate reduction current increased with the step density in a non-linear relationship. The overall current density at 0.21 V (RHE) corresponding to the peak potential of the main electrocatalytic nitrate reduction wave which was maximum at n = 2, abruptly increased with short terraces, i.e. n < 5, where the current wave of adsorbed hydrogen on the Pt stepped surface with comparatively narrow (1 1 1) terraces, denoted as H_nt, also appeared unmodified for n < 5 on voltammograms recorded in 0.1 M HClO₄ in the absence of nitrate.