A Network Topology Control and Identity Authentication Protocol with Support for Movable Sensor Nodes

It is expected that in the near future wireless sensor network (WSNs) will be more widely used in the mobile environment, in applications such as Autonomous Underwater Vehicles (AUVs) for marine monitoring and mobile robots for environmental investigation. The sensor nodes’ mobility can easily cause changes to the structure of a network topology, and lead to the decline in the amount of transmitted data, excessive energy consumption, and lack of security. To solve these problems, a kind of efficient Topology Control algorithm for node Mobility (TCM) is proposed. In the topology construction stage, an efficient clustering algorithm is adopted, which supports sensor node movement. It can ensure the balance of clustering, and reduce the energy consumption. In the topology maintenance stage, the digital signature authentication based on Error Correction Code (ECC) and the communication mechanism of soft handover are adopted. After verifying the legal identity of the mobile nodes, secure communications can be established, and this can increase the amount of data transmitted. Compared to some existing schemes, the proposed scheme has significant advantages regarding network topology stability, amounts of data transferred, lifetime and safety performance of the network

Performance Analysis for RIS-Assisted SWIPT-Enabled IoT Systems

Reconfigurable intelligent surface (RIS) is a promising technology to improve the spectral and energy efficiency of Internet of Things (IoT) systems. In this paper, we investigate an RIS-assisted simultaneous wireless information and power transmission (SWIPT) system by utilizing stochastic geometry. Moreover, we consider not only the case of random phase shift, but also the case where the phase shift of the RIS are aligned to the k -th IoT device. We first derive the closed-form expressions of the uplink outage probability and the average uplink data size for the k -th IoT device under the Rayleigh channel. Then, we extend the performance analysis to the Rician fading channel and multi-antenna scenarios. Finally, extensive numerical results have been carried out to verify the effectiveness of our derived results

Performance Analysis of RIS-Assisted Wireless Communications With Energy Harvesting

In this paper, we investigate a reconfigurable intelligent surface (RIS)-assisted wireless communication system with energy harvesting. In the single information user (IU) scenario, we consider the power control of base station (BS) and the random deployment of energy users (EUs). To this end, we first characterize the statistical features of the channel gains over BS-RIS-IU and BS-RIS-EU cascaded links. Then, we derive a closed-form expression of the information outage probability (IOP) of the IU and show an upper bound of the energy outage probability (EOP) of EUs by invoking the Jensen's inequality. Furthermore, we consider two more general extensions, namely, the existence of imperfect phase alignment and multiple IUs. Finally, the correctness of the analysis results is verified by Monte-Carlo simulation

IRS-Assisted Short Packet Wireless Energy Transfer and Communications

In this letter, we analyse and optimize an intelligent reflecting surface (IRS)-assisted ultra-reliable and low-latency communications (uRLLC) system supported by wireless energy transfer (WET) technology, in which short packets are used in both the WET and wireless information transfer (WIT) phases. We first present the statistical features of the signal-to-noise ratio (SNR) of the system. Then, we derive an approximate closed-form expression of the average packet error probability (APEP). Additionally, we optimize the channel uses in the WET and WIT phases to maximize the effective throughput (ET) of the system. Finally, the effectiveness of the proposed solution is verified by Monte-Carlo simulation

Resveratrol activation of SIRT1/MFN2 can improve mitochondria function, alleviating doxorubicin‐induced myocardial injury

Background Doxorubicin is a widely used cytotoxic chemotherapy agent for treating different malignancies. However, its use is associated with dose-dependent cardiotoxicity, causing irreversible myocardial damage and significantly reducing the patient's quality of life and survival. In this study, an animal model of doxorubicin-induced cardiomyopathy was used to investigate the pathogenesis of doxorubicin-induced myocardial injury. This study also investigated a possible treatment strategy for alleviating myocardial injury through resveratrol therapy in vitro. Methods Adult male C57BL/6J mice were randomly divided into a control group and a doxorubicin group. Body weight, echocardiography, surface electrocardiogram, and myocardial histomorphology were measured. The mechanisms of doxorubicin cardiotoxicity in H9c2 cell lines were explored by comparing three groups (phosphate-buffered saline, doxorubicin, and doxorubicin with resveratrol). Results Compared to the control group, the doxorubicin group showed a lower body weight and higher systolic arterial pressure, associated with reduced left ventricular ejection fraction and left ventricular fractional shortening, prolonged PR interval, and QT interval. These abnormalities were associated with vacuolation and increased disorder in the mitochondria of cardiomyocytes, increased protein expression levels of α-smooth muscle actin and caspase 3, and reduced protein expression levels of Mitofusin2 (MFN2) and Sirtuin1 (SIRT1). Compared to the doxorubicin group, doxorubicin + resveratrol treatment reduced caspase 3 and manganese superoxide dismutase, and increased MFN2 and SIRT1 expression levels. Conclusion Doxorubicin toxicity leads to abnormal mitochondrial morphology and dysfunction in cardiomyocytes and induces apoptosis by interfering with mitochondrial fusion. Resveratrol ameliorates doxorubicin-induced cardiotoxicity by activating SIRT1/MFN2 to improve mitochondria function