Candida fungemia in neonates treated with fluconazole: report of forty cases, including eight with meningitis

PURPOSE OF THE STUDY: To assess efficacy and safety of fluconazole in neonates with Candida fungemia. STUDY DESIGN: Multicenter prospective protocol of all fungemias appearing between January 1, 1993, and December 31, 1997, in four major university hospitals. RESULTS: Forty neonates, 28 of them with very low birth weight (<1500 g; 30.5 median gestation week), with documented Candida albicans fungemia were treated with intravenous fluconazole in a daily dosage of 6 mg/kg once daily for 6 to 48 days. Thirty-four received fluconazole as monotherapy and 6 received it in combination with amphotericin B. Thirty-two (80%) were cured; 4 of them relapsed despite at least 14 days of therapy, but they were ultimately cured without sequelae. Eight other neonates died, 4 because of fungal infection and 4 because of prematurity or hemorrhage or lung failure, with fungemia (20% overall and 10% attributable mortality). Two neonates had elevated liver enzymes during fluconazole therapy and 2 others had elevated serum creatinine during fluconazole monotherapy. In none of them did these abnormalities necessitate discontinuation of antifungal therapy. In 8 neonates fungal meningitis developed as a complication of fungemia. All but 3 fungemias were C. albicans; 3 were Candida parapsilosis. CONCLUSIONS: Fluconazole was safe and effective antifungal therapy even in complicated or Candida fungemia in neonates and in infants with very low birth weight.     

Heat conduction in Ba1?xKxBiO3

We have investigated heat conduction of single crystal Ba_1–xK_xBiO₃ in the temperature range of 2–300 K and in a magnetic field of up to 6 Tesla. Temperature dependence of thermal conductivity(T) reveals the participation of both electrons and phonons with their relative contributions that depend critically on the potassium doping concentration. Crystals underdoped with potassium (samples with higherT _c) exhibit a strong suppression of and a glass-like temperature dependence. In contrast, those with a higher potassium content (lowerT _c) show an increase as temperature decreases with a peak near 23 K. Field dependence of(H) is also very sensitive to the level of potassium doping. Crystals exhibiting a large phonon contribution show an initial drop in(H) at low fields followed by a minimum and then a slow rise to saturation as the field increases. The initial drop is due to the additional phonon scattering by magnetic vortices as the sample enters a mixed state. The high field behavior of(H), arising from a continuous break-up of Cooper pairs, exhibits scaling which suggests the presence of an unconventional superconducting gap structure in this material.     

Risks in subcontracting: Subcontract conditions

The use of non-standard, contractor-prepared subcontract conditions is widespread in the Australian construction industry. Many conditions in such subcontracts are harsh and are viewed by Australian subcontractors as the most critical risk for which they make risk allowances in the bid price.     

Traction Energy Cost Reduction of the WMATA Metrorail System

An energy cost reduction study was conducted on the Washington Metropolitan Area Transit Authority Metrorail system. Its primary objectives were to classify primary energy end uses and identify conservation methods which have the highest potential for reducing the electric bill. The effort involved analyzing present energy costs, developing cost- effective conservation strategies, determining the savings associated with the strategies by simulation, recommending appropriate strategies for implementation and outlining a program for executing the recommendations. Although the effort involved both traction and support energy, only the traction energy aspects of the study are reported. It is the first time that the energy management model developed for the transit industry by the Rail Systems Center at Carnegie-Mellon University was comprehensively applied to a rapid transit property. The application was verified by comparing the simulated results to actual data. For anl practical purposes, the simulated results agree to within three percent of the actual energy consumption. Four traction energy conservation strategies were recommended for implementation based on high benefit and low cost. These are coasting, passenger load factor improvement, planned catch-up operation, and regeneration of braking energy. All of these strategies have payback periods of less than three years.     

The Interpretation of Train Rolling Resistance from Fundamental Mechanics

Past efforts in railway improvement have focused on increased train stability and ride quality for safe and smooth operations at higher speed. The question of energy consumption has rarely been considered. In view of projections of higher fuel costs and increased rail traffic volume, energy effects caused by improved train resistance should be considered. First-order expressions for the rolling resistance of freight trains on level tangent track were derived from the basic principles of physics and engineering. The average power dissipated by the suspension system was obtained from a linear model of the track train system. Hysteresis in the soil is computed using basic principles of soil mechanics. Losses due to wheel rolling friction, imposed wheel sliding, and bearings were estimated from simple engineering and considerations. Rolling resistance as would be measured in coast down or drawbar pull tests on level tangent track is found to depend strongly on the quality of the track as well as weight and speed. On good track, most of the rolling resistance is due to bearing resistance, while on poor track, suspension losses predominate. Empirical expressions such as the Davis formula, which have been used in the past by the railroad industry, are unable to describe train rolling resistance adequately because of the way in which they are parameterized. Some of the parameter values obtained from fits to experimental data do not carry the physical meaning with which they were traditionally associated.     

Doping and Defect Structure of Tetradymite-Type Crystals

Nonstoichiometry of tetradymite-type crystals A₂^VB₃^VI that are grown from stoichiometric melts leads to the formation of native defects in the crystal lattice (predominantly antisite defects, A_B⁻¹ and vacancies V_B⁺² in the anion sublattice). This paper summarizes the basic ideas concerning a point defect model in A₂^VB₃^VI crystals. It turns out that a variety of doping elements interact with the native defects. Such interactions alter the concentration of free charge carriers, affect the doping efficiency, and modify the transport properties. Detailed understanding of the defect structure in tetradymite-type crystals is very important as it impacts on the efficiency of these materials when used as active elements in thermoelectric coolers.     

Charge-Compensated <Emphasis Type="Italic">n</Emphasis>-Type Skutterudites

Ba+Yb double-filled n-type skutterudites with a modest degree of charge compensation by Fe on the Co lattice have been synthesized and compacted by spark-plasma sintering, and their thermoelectric properties evaluated at temperatures up to 800 K. Although this approach to making n-type skutterudites seems counterintuitive, the presence of Fe leads to a reduction in the thermal conductivity while it preserves a robust Seebeck coefficient. Consequently, a high ZT in excess of 1.3 was achieved at 800 K in these Fe-containing n-type skutterudite compounds.     

Dielectric slab matched ferrite gyrator

A 180° nonreciprocal ferrite phase shifter with stepped dielectric impedance transformer sections at both ends is designed using the method of field expansion into eigenmodes. The rigorous optimisation method includes the higher-order mode interaction between the step discontinuities. The design achieves compact and simple components, as relatively thick, and consequently short, uniform ferrite slabs of standard dimensions may utilised. A computer-optimized design example provides about 180° ± 1° nonreciprocal differential phase shift between 12.2 and 12.8 GHz together with more than 24dB return loss.