Selenium status in diet affects acetaminophen-induced hepatotoxicity via interruption of redox environment

Aims: Drug-induced liver injury, especially acetaminophen (APAP)-induced liver injury, is a leading cause of liver failure worldwide. Mouse models were used to evaluate the effect of microelement selenium levels on the cellular redox environment and consequent hepatotoxicity of APAP. Results: APAP treatment affected mouse liver selenoprotein thioredoxin reductase (TrxR) activity and glutathione (GSH) level in a dose- and time-dependent manner. Decrease of mouse liver TrxR activity and glutathione level was an early event, and occurred concurrently with liver damage. The decreases in the GSH/glutathione disulfide form (GSSG) ratio and TrxR activity, and the increase of protein S-glutathionylation were correlated with the APAP-induced hepatotoxicity. Moreover, in APAP-treated mice both mild deprivation and excess supplementation with selenium increased the severity of liver injury compared with those observed in mice with normal dietary selenium levels. An increase in the oxidation state of the TrxR-mediated system, including cytosolic thioredoxin1 (Trx1) and peroxiredoxin1/2 (Prx1/2), and mitochondrial Trx2 and Prx3, was found in the livers from mice reared on selenium-deficient and excess selenium-supplemented diets upon APAP treatment. Innovation: This work demonstrates that both Trx and GSH systems are susceptible to APAP toxicity in vivo, and that the thiol-dependent redox environment is a key factor in determining the extent of APAP-induced hepatotoxicity. Dietary selenium and selenoproteins play critical roles in protecting mice against APAP overdose. Conclusion: APAP treatment in mice interrupts the function of the Trx and GSH systems, which are the main enzymatic antioxidant systems, in both the cytosol and mitochondria. Dietary selenium deficiency and excess supplementation both increase the risk of APAP-induced hepatotoxicity.</p

Robust Secure Resource Allocation for RIS-Aided SWIPT Communication Systems

Aiming at the influence of channel uncertainty, user information leakage and harvested energy improvement, this paper proposes a robust resource allocation algorithm for reconfigurable intelligent reflector (RIS) multiple-input single-output systems based on imperfect channel state information. First, considering the legal user minimum secret rate constraint, the base station maximum transmit power constraint and the RIS phase shift constraint with the bounded channel uncertainty, a joint optimization of the base station active beam, energy beam and RIS phase shift is established. A multivariate coupled nonlinear resource allocation problem for matrices is addressed. Then, using S-procedure and alternating optimization methods, the original non-convex problem is transformed into a deterministic convex optimization problem and an alternating optimization algorithm based on continuous convex approximation is proposed. The simulation results show that the proposed algorithm has better fairness harvested energy compared with the traditional robust algorithm

CSI-Impaired Beamforming Optimization for Dense MIMO Communication Networks

This paper studied the robust beamforming for dense transmission systems with imperfect channel state information (CSI). The objective was to maximize the minimum signal to interference plus noise ratio (SINR) in the constraint of the per base station (BS) power. By performing the uplink–downlink duality theory, the referred non-convex optimization problem can be changed into the equivalent uplink decoupling optimization problem. Then, we proposed the instantaneous updating uplink–downlink power algorithm, which relies on instantaneous CSI for the finite system. For the massive MIMO system, to obtain the solution to the problem required for power to instantaneously update, we proposed the updating uplink–downlink power algorithm, which only requires statistical CSI, by applying the random matrix theory. The simulation results show the feasibility and effectiveness of our proposed algorithms

CSI-Impaired Beamforming Optimization for Dense MIMO Communication Networks

This paper studied the robust beamforming for dense transmission systems with imperfect channel state information (CSI). The objective was to maximize the minimum signal to interference plus noise ratio (SINR) in the constraint of the per base station (BS) power. By performing the uplink&ndash;downlink duality theory, the referred non-convex optimization problem can be changed into the equivalent uplink decoupling optimization problem. Then, we proposed the instantaneous updating uplink&ndash;downlink power algorithm, which relies on instantaneous CSI for the finite system. For the massive MIMO system, to obtain the solution to the problem required for power to instantaneously update, we proposed the updating uplink&ndash;downlink power algorithm, which only requires statistical CSI, by applying the random matrix theory. The simulation results show the feasibility and effectiveness of our proposed algorithms

Interaction Behaviours between Soliton and Cnoidal Periodic Waves for Nonlocal Complex Modified Korteweg–de Vries Equation

The reverse space-time nonlocal complex modified Kortewewg–de Vries (mKdV) equation is investigated by using the consistent tanh expansion (CTE) method. According to the CTE method, a nonauto-Bäcklund transformation theorem of nonlocal complex mKdV is obtained. The interactions between one kink soliton and other different nonlinear excitations are constructed via the nonauto-Bäcklund transformation theorem. By selecting cnoidal periodic waves, the interaction between one kink soliton and the cnoidal periodic waves is derived. The specific Jacobi function-type solution and graphs of its analysis are provided in this paper

Theoretical Investigation of the Charge Transport Properties of the DPTTA p-Type Single Crystal to the Ambipolar DPTTA-F4TCNQ Cocrystal

Our research has been conducted on the charge transport properties of the single-crystal DPTTA and the cocrystal DPTTA-F4TCNQ using the density functional theory coupled with incoherent charge-hopping model. Charge mobility is primarily considered from the combination of reorganization energy and charge transfer integral, which are important parameters in model of the charge-hopping model. The reorganization energy of DPTTA in both single-crystal and cocrystal forms exhibits similar values. Consistent with the properties of super-exchange coupling and direct coupling when under the same type of coupling mechanism, it decreases with increasing distance from the core molecule. We conclude this section by using kinetic Monte Carlo combined with Einstein's equation to derive the charge mobility, and find it to be consistent with the theoretical analysis. In our study, we propose corresponding theoretical guidelines for the rational realization of the ambipolarity of D-A complexes, hoping to contribute to the understanding and rational design of the basic mechanism of D-A complexes

Ambipolar Charge Transport of PCNTC-O and PCNTC-R Cocrystals Obtained Under 1:2 and 1:1 Ratios of Donor and Acceptor

The efficiency of microelectronic devices depends greatly on the charge transport performance of organic semiconductors. The purpose of this work is to analyze the effect of donor-acceptor (D-A) cocrystals on the charge transport characteristics of organic semiconductors using the Marcus theory of electron transfer combined with kinetic Monte Carlo simulations. For two different cocrystals, sesquikis (benzene-1,2,4,5-tetracarbonitrile) 2-(1,3-benzothiazol-2-yl)-3-(pyren-1-yl)prop-2-eneni-trile(PCNTC-O) and ben-zene-1,2,4,5-tetracarbonitrile 2-(1,3-benzothiazol-2-yl)-3-(pyren-1-yl)pr-op-2-enenitrile(PCNTC-R) cocrystals, were investigated using 2-(benzo[d]-thiazol-2-yl)-3-(pyren-1-yl)acrylonitrile (Py-BZTCN) as the donor and 1,2,4,5-tetracyanobenzene (TCNB) as the acceptor mixed at 1:2 and 1:1 ratios, respectively. According to our calculations, PCNTC-O and PCNTC-R both exhibit bipolar charge transport behaviour with mobilities electron/hole attaining 0.0104/0.1252 and 0.0241/0.0598 cm2/Vs, respectively

Research on the Characteristic of the Electrical Contact Resistance of Strap Contacts Used in High Voltage Bushings

As an important electrical connection component in electrical equipment, the strap contact is directly related to the long-term operation stability of equipment. The electrical contact resistance (ECR) of the electrical connection structure is an important indicator for evaluating the reliability of the electrical contact system. In this research, the theoretical calculation of ECR of the strap contacts used by the G-W theoretical model and the fractal theoretical model is improved and compared. After comparison with the experimental measurement values, the rationality and accuracy of the two theoretical models are discussed. The results show that when the load is small (1–3 N), the maximum error of G-W model is 41%, while the fractal model method has a maximum error of 9%. When the load is large (4–10 N), the results of the two are almost the same, and the errors are both within 14%. In summary, the error range of the fractal model is smaller and the change trend is closer to the experimental value, which is suitable for a relatively better ECR analytical calculation theory. The research results can provide a theoretical basis for research on the electrical contact performance of the electrical contact structure of electrical equipment