In this paper, we adopt a three-stage based uplink channel estimation protocol with reduced pilot overhead for an reconfigurable intelligent surface (RIS)-aided multi-user (MU) millimeter wave (mmWave) communication system, in which both the base station (BS) and RIS are equipped uniform planar array (UPA). Specifically, Stage I, state information (CSI) of typical user is estimated. To address ...

Ca2+-activated K+ channels from rat muscle transverse tubule membranes were inserted into planar phospholipid bilayers, and the activation of these channels by Ca2+ was studied. On the cytoplasmic side of the channel, calcium ions (in the range 10-100 mumol l-1) increase the opening probability of the channel in a graded way. This 'activation curve' is sigmoid, with an average Hill coefficient ...

Sphingolipids stimulate the release of Ca2+ from intracellular stores. However, the mechanism by which this process occurs has not been characterized. Through single-channel recording from microsomes incorporated into planar lipid bilayers, we describe a novel channel that gates Ba2+ in response to sphingosylphosphorylcholine. The channel is both ligand-gated and voltage-modulated. Maximal open...

The channel activity of gramicidin A in free-standing planar lipid bilayers with different charges of polar head groups and various lengths of hydrocarbon tails were analyzed in terms of the channel conductance, the lifetime of channel events and the magnitude of integrated currents. The channel activity of gramicidin A in lipid bilayers is tunable by adjusting the membrane composition. The in ...

the zero-divisor graph of a commutative ring r with respect to nilpotent elements is a simple undirected graph $gamma_n^*(r)$ with vertex set z_n(r)*, and two vertices x and y are adjacent if and only if xy is nilpotent and xy is nonzero, where z_n(r)={x in r: xy is nilpotent, for some y in r^*}. in this paper, we investigate the basic properties of $gamma_n^*(r)$. we discuss when it will be eu...

The capacity of a Multiple-Input Multiple-Output (MIMO) system depends on the channel matrix as well as the Signal-to-Noise ratio. A novel dualpolarized planar channel model with one or two scattering rings is used to compare the capacity of different antenna arrays. The correlation between channel matrix elements of the presented channel model and the statistical Kronecker model is also compar...

The molecular effects of droperidol (C22H22FN3O2) on single sodium channels from the human brain were investigated using the electrophysiological planar lipid-bilayer technique. Droperidol (0.05-0.8mM) induced a concentration dependent and voltage independent reduction in the time averaged single channel conductance by two mechanisms: a reduction in the fractional channel open time (major effec...