Transforming growth factor-β (TGF-β) responsiveness in cultured cells can be modulated by TGF-β partitioning between lipid raft/caveolae- and clathrin-mediated endocytosis pathways. Lipid rafts are plasma membrane microdomains with an important role in cell survival signaling, and cholesterol is necessary for the lipid rafts’ structure and function. Euphol is a euphane-type triterpene alcohol that is structurally similar to cholesterol and has a wide range of pharmacological properties, including anti-inflammatory and anti-cancer effects. In the present study, euphol suppressed TGF-β signaling by inducing TGF-β receptor movement into lipid-raft microdomains and degrading TGF-β receptors.
The level of multiple access interference (MAI) in code division multiple access (CDMA) communication systems is a time-varying parameter related to the number of active users. Almost all existing multiuser detection schemes were designed based on a priori information of the active users. In many situations, however, the multiuser receiver does not know the number of active users, and the receiver designed for the detection of all users may lead to poor performance. To develop a more efficient detection scheme in practical applications, we propose a two-stage detection structure consisting of preprocessing (identification) and postprocessing (detection). In the preprocessing, we apply the subspace concept and a method based on the multiple signal classification (MUSIC) algorithm [1] to identify the active users while requiring only a priori knowledge of all of the users' signature sequences. The proposed preprocessor is shown to be asymptotically near-far resistant, and to have the ability to identify the active users in a simple and reliable way. While in the detection process, as we efficiently use the active users' information in every observation interval, the performance is clearly improved compared to the conventional structure without identification. Moreover, the effect of imperfect identification on the decorrelating detector is also extensively analyzed. Though the decorrelating detector's inherent near-far resistant characteristic is impaired by imperfect identification, the proposed structure still outperforms the conventional structure in the general near-far environment.Index Terms-Code division multiple access (CDMA), identification, multiuser detection, multiple signal classification (MU-SIC), near-far resistant.
This paper proposes a prefiltering-based scheme for pulsed ultra-wideband (UWB) system by shifting the signal processing needs from the receiver at the radio terminal (RT) to the transmitter at the fixed access point (AP) where power and computational resources are plentiful. We exploit antenna array in the transmitter of AP and take advantage of the spatial and temporal diversities to mitigate the multiuser interference (MUI) as well as preequalize the channel impulse response (CIR) of a timehopping (TH) multiple access UWB communication system. Three prefiltering schemes are developed to meet different criteria. A simple correlation receiver is proposed at the RT to combine the desired signal stemmed from all the transmitting antennas. The performances under different scenarios are extensively evaluated over multiple-input single-output (MISO) channels.
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