We show that the analytic structure of dynamical exchange-correlation (xc) kernels semiconductors and insulators can be sensed in terms its poles, which mark physically relevant frequencies system where counterphase motion discrete collective excitations occurs: If excited, modes counterbalance each other, making exhibit none at all or extremely weak density response. This property employed to ...

the hypotensive effect of garlic has been well-documented in human subjects and animals. since endothelial activity regulates vascular reactivity in physiological and pathophysiological conditions, the aim of the present study was to investigate the effect of garlic on endothelium-dependent and independent relaxation of rat aorta for elucidation of mechanism of the garlic anti-hypertensive effe...