402 research outputs found
Energy-Efficient Optimization for Wireless Information and Power Transfer in Large-Scale MIMO Systems Employing Energy Beamforming
In this letter, we consider a large-scale multiple-input multiple-output
(MIMO) system where the receiver should harvest energy from the transmitter by
wireless power transfer to support its wireless information transmission. The
energy beamforming in the large-scale MIMO system is utilized to address the
challenging problem of long-distance wireless power transfer. Furthermore,
considering the limitation of the power in such a system, this letter focuses
on the maximization of the energy efficiency of information transmission (bit
per Joule) while satisfying the quality-of-service (QoS) requirement, i.e.
delay constraint, by jointly optimizing transfer duration and transmit power.
By solving the optimization problem, we derive an energy-efficient resource
allocation scheme. Numerical results validate the effectiveness of the proposed
scheme.Comment: 4 pages, 3 figures. IEEE Wireless Communications Letters 201
Demand Shaping to Achieve Steady Electricity Consumption with Load Balancing in a Smart Grid
The purpose of this paper is to study conflicting objectives between the grid
operator and consumers in a future smart grid. Traditionally, customers in
electricity grids have different demand profiles and it is generally assumed
that the grid has to match and satisfy the demand profiles of all its users.
However, for system operators and electricity producers, it is usually most
desirable, convenient and cost effective to keep electricity production at a
constant rate. The temporal variability of electricity demand forces power
generators, especially load following and peaking plants to constantly
manipulate electricity production away from a steady operating point
Error Correction for Cooperative Data Exchange
This paper considers the problem of error correction for a cooperative data
exchange (CDE) system, where some clients are compromised or failed and send
false messages. Assuming each client possesses a subset of the total messages,
we analyze the error correction capability when every client is allowed to
broadcast only one linearly-coded message. Our error correction capability
bound determines the maximum number of clients that can be compromised or
failed without jeopardizing the final decoding solution at each client. We show
that deterministic, feasible linear codes exist that can achieve the derived
bound. We also evaluate random linear codes, where the coding coefficients are
drawn randomly, and then develop the probability for a client to withstand a
certain number of compromised or failed peers and successfully deduce the
complete message for any network size and any initial message distributions
Joint Rate Selection and Wireless Network Coding for Time Critical Applications
In this paper, we dynamically select the transmission rate and design
wireless network coding to improve the quality of services such as delay for
time critical applications. With low transmission rate, and hence longer
transmission range, more packets may be encoded together, which increases the
coding opportunity. However, low transmission rate may incur extra transmission
delay, which is intolerable for time critical applications. We design a novel
joint rate selection and wireless network coding (RSNC) scheme with delay
constraint, so as to minimize the total number of packets that miss their
deadlines at the destination nodes. We prove that the proposed problem is
NPhard, and propose a novel graph model and transmission metric which consider
both the heterogenous transmission rates and the packet deadline constraints
during the graph construction. Using the graph model, we mathematically
formulate the problem and design an efficient algorithm to determine the
transmission rate and coding strategy for each transmission. Finally,
simulation results demonstrate the superiority of the RSNC scheme.Comment: Accepted by 2012 IEEE Wireless Communications and Networking
Conference (WCNC
Protective effect of astragalus injection against myocardial injury in septic young rats via inhibition of JAK/STAT signal pathway and regulation of inflammation
Purpose: To investigate the protective effect of astragalus injection against myocardial injury in septic young rats, and the underlying mechanism of action.
Methods: Seventy-two healthy Sprague Dawley (SD) rats were randomly selected and used to establish a young rat model of sepsis. The young rats were randomly divided into 3 groups: sham, model and astragalus injection groups. Each group had 24 young rats. Serum cardiac troponin I (cTnI), IL-10, IL-6, JAK2 and STAT3 were measured after op.
Results: Compared with sham group, serum cTnI level in the model group was significantly higher, while serum cTnI level of the drug group was significantly lower than that of the model group (p < 0.05). Compared with model group, the level of IL-10 in the myocardial tissue of the drug group was significantly elevated, while IL-6 level was lower (p < 0.05). Relative to sham rats, myocardial JAK2 and STAT3 protein levels in model rats were high. However, myocardial JAK2 and STAT3 proteins in the drug-treated rats were significantly downregulated, relative to model rats (p < 0.05).
Conclusion: Astragalus injection upregulates IL-10 and IL-6 in rats by inhibiting the activation of JAK/STAT signal pathway, and via maintenance of pro-inflammation/anti-inflammation balance. Thus, astragalus exerts protective effect against myocardial injury in sepsis, and can potentially be developed for use as such in clinical practice.
Keywords: Astragalus injection, JAK/STAT signal pathway, Pro-inflammatory/anti-inflammatory imbalance, Sepsis, Myocardial injur
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