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Piezoelectric cantilever beams are among the most popular vibration energy harvesting devices. Homogenization of the spatial distribution of axial strain along those beams increases harvesting efficiency. The general approach to minimize axial strain variation is to use triangular or trapezoidal width profiles. In this study, a width profile function that includes curved shapes is proposed and a finite element–based optimization scheme is constructed to maximize harvesting efficiency. A distribution parameter is defined for quantifying the strain uniformity. Optimization is performed for various tip mass values, using this parameter as the objective function. It is shown that curved beam profiles exhibit less variation in axial strain, compared to triangular and rectangular beams. Optimized shapes for minimal strain variation at resonance are determined. Experimental results also validate the findings of the optimization. At least 22% increase in strain uniformity is obtained with the optimized-shaped beam, compared to a triangular beam when no tip mass is used. The increase in strain uniformity becomes 29% when the tip mass is increased to 5 g. The results indicate the potential of employing beam-type piezoelectric energy harvesters with optimized width profiles. [ABSTRACT FROM AUTHOR]

Glutamate is believed to be the predominant excitatory neurotransmitter in the networks responsible for itch-related behavior. Beta-lactam antibiotics were shown to exert neuroprotective effects by increasing expression of the glutamate transporter GLT-1. We observed whether repeated administration of the beta-lactam antibiotic ceftriaxone suppresses serotonin-induced itch-related behavior (similarly to the effect of this agent on pain transmission) in mice. Chronic, but not acute, ceftriaxone introductions reduced the number of serotonin-induced scratches; dihydrokainic acid, a selective GLT-1 transporter inhibitor, partly but significantly abolished this effect of ceftriaxone. Our findings suggest that GLT-1 activation by beta-lactam antibiotics looks promising for the treatment of chronic itch. [ABSTRACT FROM AUTHOR]

Summary. Morphine has long been known to have potent effects on body temperature. It has been suggested that both N-methyl-D-aspartate (NMDA) receptors and nitric oxide (NO) pathway are involved in thermoregulation and also known to play important roles in some of morphine effects. The aim of this study was therefore to investigate the contribution of NMDA receptors and NO to the thermoregulatory effect of morphine. Morphine produced a hypothermic effect, especially at the dose of 10 mg/kg. Ketamine (5–40 mg/kg, i.p.) and NG-nitro-L-arginine-methyl ester (L-NAME, 1–100 mg/kg, i.p.) also produced hypothermic effects with their higher doses. At doses which themselves produced no effect on colonic temperature in mice, both ketamine (10 mg/kg, i.p.) and L-NAME (10 mg/kg, i.p.) enhanced the hypothermic effect of morphine (10 mg/kg, i.p.). These results further support the relationship between NO and NMDA receptors and suggest a possible role of NMDA-NO pathway in the thermoregulatory effect of morphine. [ABSTRACT FROM AUTHOR]