Visualization of oscillating flow in a double-inlet pulse tube refrigerator with a diaphragm inserted in a bypass-tube

The double-inlet pulse tube refrigerator that has a diaphragm inserted in a bypass-tube, which enabled it to transmit a pressure oscillation whereas to obstruct a DC gas flow, was manufactured and tested. The oscillating flow behavior inside of the refrigerator was studied by using a smoke-wire flow visualization technique. It was found that if the diaphragm was optimized, the performance would be improved more than that of the refrigerator with a bypass valve due to the increase in the PV work of the gas and the decrease in the convective heat loss caused by a secondary flow

Paeoniflorin ameliorates acquisition impairment of a simple operant discrimination performance caused by unilateral nucleus basalis magnocellularis lesion in rats

The effect of paeoniflorin on learning impairment of operant brightness discrimination performance　was investigated in rats with unilateral nucleus basalis magnocellularis（NBM）lesion. The animals　with unilateral NBM lesion exhibited a significant acquisition impairment of brightness discrimination task during the early phase of a training period（1-5days after starting the training session). When　administered daily during a training period，paeoniflorin significantly improved the learning impairment　of unilateral NBM-lesioned rats at 0.01 but not 0.1mg／kg／day（p.o.）. Tacrine （0.3mg／kg／day，p.o.）， a　cholinesterase inhibitor，also significantly ameliorated the learning deficit. These results suggest that　paeoniflorin improves the impairment of non-spatial learning performance caused by cholinergic　dysfunction in rats and that it may have a beneficial effect on senile dementia