s. saffar

Acoustic scaling is one of the efficient techniques for measuring acousticparameters of large and luxury places. Due to the range of acousticscaling frequency, an airborne ultrasonic transducer has been used fortransporting the power to the air. One major problem of ultrasonictransducers, radiating acoustic energy into the air, is to find the properacoustic impedance of one or more matching layers. This work aims atdeveloping an original solution to the acoustic impedance mismatchbetween transducer and air. Therefore we consider three piezoelectrics,PZT, PVDF, and EMFi transducers and air that have high acousticimpedance deference. We proposed the use of a genetic algorithm (GA) toselect the best acoustic impedances for matching layers from the materialdatabase for a narrow band ultrasonic transducer that works at afrequency below the 1MHz by considering attenuation. This yields ahighly more efficient transmission coefficient. Also, the results showedthat by using the increasing number of layers we can increase our chanceto find the best sets of materials with valuable both in acoustic impedanceand low attenuation. Precisely, the transmission coefficient is almosthigher than 80% for the more studied cases.

Chronic morphine use leads to structural changes in the brain. Some studies have shown the antioxidant and neuroprotective effects of Epigallocatechin gallate (EGCG) as a main polyphenol of green tea. Therefore, the aim of this study was to investigate the effect of EGCG on working memory in morphine-treated rats.

In this experimental study, 32 male Wistar rats were divided into 4 experimental groups (8 rats in each group): 1- control; 2- Morphine group (the animals received 40 mg/kg morphine for 4 weeks, once a day, s.c.); 3 and 4- Morphine + EGCG, the animals received morphine (40 mg/kg, 4 weeks, once a day, s.c.) and EGCG (5 and 50 mg/kg, once a day, i.p.). To evaluate the working memory, Y-maze spontaneous alternation was used. To measure the level of TNF-α protein expression in brain hippocampus tissue, the western blot test was used. One-way ANOVA with Tukey’s post hoc test was used for data analysis.

Intraperitoneal morphine injection resulted in working memory deficits and increased TNF-α protein expression levels compared to the control group (p<0.001). Moreover, intraperitoneal injection of 50 mg/kg EGCG in morphine treated rats significantly improved working memory (p<0.01) and decreased TNF-α protein expression level (p<0.05) compared to solely morphine treated group.

EGCG improved morphine induced working memory deficits in rats.