Bimorph material/structure designs for high sensitivity flexible surface acoustic wave temperature sensors.

A fundamental challenge for surface acoustic wave (SAW) temperature sensors is the detection of small temperature changes on non-planar, often curved, surfaces. In this work, we present a new design methodology for SAW devices based on flexible substrate and bimorph material/structures, which can maximize the temperature coefficient of frequency (TCF). We performed finite element analysis simulations and obtained theoretical TCF values for SAW sensors made of ZnO thin films (~5 µm thick) coated aluminum (Al) foil and Al plate substrates with thicknesses varied from 1 to 1600 µm. Based on the simulation results, SAW devices with selected Al foil or plate thicknesses were fabricated. The experimentally measured TCF values were in excellent agreements with the simulation results. A normalized wavelength parameter (e.g., the ratio between wavelength and sample thickness, λ/h) was applied to successfully describe changes in the TCF values, and the TCF readings of the ZnO/Al SAW devices showed dramatic increases when the normalized wavelength λ/h was larger than 1. Using this design approach, we obtained the highest reported TCF value of -760 ppm/K for a SAW device made of ZnO thin film coated on Al foils (50 µm thick), thereby enabling low cost temperature sensor applications to be realized on flexible substrates.

Submicrometer ferromagnetic NOT gate and shift register.

An all-metallic submicrometer device is demonstrated experimentally at room temperature that performs logical NOT operations on magnetic logic signals. When this two-terminal ferromagnetic structure is incorporated into a magnetic feedback loop, the junction performs a frequency division operation on an applied oscillating magnetic field. Up to 11 of these junctions are then directly linked together to create a magnetic shift register.

Repellency and efficacy of 65% permethrin and 9.7% fipronil against Ixodes ricinus.

Two topically applied spot-on products--65% permethrin (Defend Exspot Treatment for Dogs, Schering-Plough Animal Health, Union, NJ) and 9.7% fipronil (Frontline Spot On Dog, Merial Limited, Iselin, NJ)--used for canine flea and tick control were evaluated for repellency against Ixodes ricinus, the tick species that is the primary vector of Lyme disease in Europe. Eighteen dogs were randomly assigned to the following treatment groups (n = 6): (1) 65% permethrin, (2) 9.7% fipronil, or (3) untreated control. Dogs were exposed to ticks in individually assigned cages with a carpet that covered =70% of the cage bottom. Dogs in treatment groups 1 and 2 were treated in accordance with label directions for each re-spective product on study day 0. Fifty unfed, male and female adult ticks were placed in the cages 15 to 30 minutes before the dogs. The dogs were placed in the cages for a 2-hour exposure period at 2, 7, 14, 21, 28, 35, and 41 days after treatment. After a 2-hour exposure period, dogs were removed from the cages and live (attached and unattached) and dead ticks were counted on the dogs, on the carpets, and in the cages. Cages were thoroughly cleaned and new carpet was used for each tick exposure period. Treatment of dogs with 65% permethrin reduced tick numbers on dogs by 99.1% at 2 days, 99.0% at 1 week, 95.9% at 2 weeks, 88.5% at 3 weeks, 87.1% at 4 weeks, and 48.0% at 6 weeks after application. In contrast, treatment of dogs with 9.7% fipronil reduced tick numbers on dogs by 61.4% at 2 days, 51.6% at 1 week, 37.0% at 2 weeks, 33.7% at 3 weeks, 10.8% at 4 weeks, and 0% at 6 weeks after application. The efficacy of 65% permethrin was significant (P < or = .05) when compared to the control at all challenges, whereas the efficacy of 9.7% fipronil was not significant as compared to controls at 21, 28, 35, and 41 days after treatment. The 65% permethrin killed significantly more Ixodes ricinus ticks (P < or = .05) than 9.7% fipronil from 2 to 41 days after treatment. The 65% permethrin repelled 1.9-, 2.0-, 3.0-, 43.3-, 3.9-, 8.9-, and 17.3-fold more Ixodes ricinus than did 9.7% fipronil at 2, 7, 14, 21, 28, 35, and 41 days after treatment, respectively, and all differences in repellency were significant (P < or = .05).

Synthesis and radiochemical stability of 14C-cefotaxime.

14C-Cefotaxime (14C-HR 756) has been synthesised with the radiolabel in the sidechain aminothiazole ring by a multistep sequence starting from 14C-thiourea. A high specific activity batch (10400 microCi g-1), and a low specific activity batch (57.1 microCi g-1) suitable for intravenous human use were prepared; their purity, and solid-state and aqueous solution stability, are described.

Pulmonary resistance and methods of humidification in acute pulmonary failure.

In order to evaluate the effects of ultrasonic nebulization on airway resistance in respiratory failure, ten patients requiring mechanical ventilation for acute pulmonary failure were each ventilated with two humidification systems, one producing inspired air saturated with vapour at 35 degrees C, the other nebulizing water droplets ultrasonically. There was no statistically significant difference in pulmonary resistance at inspiratory flow rates of 40, 60, AND 80 1/min. A separate comparison between humidifiers in those patients with the highest resistances did not reveal any difference in response to method of humidification. In contrast to studies in other contexts, these data fail to show any significant difference, from the standpoint of effects on resistance, in the use of ultrasonic mist humidification during mechanical ventilation for respiratory failure.

Antibiotic resistance among coliform and fecal coliform bacteria isolated from sewage, seawater, and marine shellfish.

Seawater and shellfish samples collected in the vicinity of a marine sewage outfall were examined for the incidence of antibiotic resistance among coliform and fecal coliform bacteria over a 2-year period. Seventy percent or more of these two groups of bacteria from both sources were resistant to one or more antibiotics. Forty-five percent of the isolates resistant to streptomycin or tetracycline were capable of transferring all or part of their resistance pattern to an antibiotic-susceptible strain of Escherichia coli K-12.

Antibiotic resistance among coliform and fecal coliform bacteria isolated from the freshwater mussel Hydridella menziesii.

Freshwater mussels (Hydridella menziesii) collected from Lakes Rotoroa, Rotoiti, and Brunner, South Island, New Zealand, contained coliform and fecal coliform bacteria. The majority of these bacteria were resistant to one or more antibiotics, but none transferred streptomycin, tetracycline, or kanamycin resistance to an antibiotic-susceptible strain of Escherichia coli K-12.