air conditioning refrigerant r134a has value of global warming potential (gwp) 1300, which is much higher than mac directive (gwp below 150) passed in july 2006. this prompted a search for alternative refrigerant with gwp value less than 150. r1234yf is a new refrigerant which has lower gwp value of 4. effect of blower speed has been compared and flammability issue of r1234yf has been addressed...

Abstract: Seed conditioning improves germination uniformity, speed, and dormancy release. This work aimed the study physiological of Urochloa humidicola cv. Llanero, using two lots dormant seeds conditioned by imbibition with water, commercial bioregulator (auxin, gibberellin - 0.144 mM cytokinin), (0.144 1.44 mM) or 5% ethanol. Germination, dormancy, SOD activity, MDA H2O2 content were evaluat...

Background: GABAergic drugs can modulate the rewarding properties of morphine. The objective of this study was to evaluate the effects of isoniazid, as a GABAergic agent, on the rewarding effects of morphine. Methods: Eighteen groups of female mice (eight per group) were used in a conditioned place preference (CPP) study. On the conditioning phase of the CPP p...

Colchicine, a potent neurotoxin derived from plants, has been recently introduced as a degenerative toxin of small pyramidal cells in the cortical area 1 of the hippocampus (CA1). In this study, the effect of the alkaloid in CA1 on the behaviors in the conditioning task was measured. Injections of colchicine (1,5 μg/rat, intra-CA1) was performed in the male Wistar rats, while the animals were s...

introduction: one of the hallmark symptoms of posttraumatic stress disorder (ptsd) is the impaired extinction of traumatic memory. single prolonged stress (sps) has been suggested as an animal model of ptsd, since sps rats exhibited the impaired fear extinction. oxytocin (oxt) has been recently suggested as a potential pharmacotherapy for treatment of ptsd. in this study, using sps rats we inve...

introduction: biological effects of magnetic fields have been investigated by scientists for many years and a vast amount of research using different frequencies and intensities have been performed on humans and laboratory animals. the results of these studies, which have mostly been done by applying high frequencies, have shown that electromagnetic fields are effective on structure and functio...

statement of problem: the achievement of a good and durable dentin/composite resin bond is an important task in restorative dentistry. the application of acid conditioners and dentin bonding agents is an accepted method to enhance this bond strength. pretreating of dentin surface by laser irradiation seems to be a supplemental way to obtain better results, since lased dentin is more roughened a...

1. Seed dispersal is considered critical for shaping the spatial structure of plant populations, though little empirical effort has been made to interpret this effect in terms of the scale at which plant species are distributed and cope with environmental heterogeneity. We assessed the spatial role of seed dispersal in Tristerix corymbosus , a mistletoe dispersed exclusively in the temperate fo...

background: polymerization of resin‑modified glass‑ionomers (rmgis) is mediated through two competing mechanisms: an acid‑base reaction and a light‑dependent resin polymerization. furthermore, pre‑conditioning with acid has resulted in an increase in enamel bond strength of some rmgis. this in vitro study evaluated the effect of pre‑conditioning and/or delayed irradiation on bond strength of th...