Selenomethionine Attenuated H2O2-Induced Oxidative Stress and Apoptosis by Nrf2 in Chicken Liver Cells.

Earlier studies have shown that selenomethionine (SM) supplements in broiler breeders had higher deposition in eggs, further reduced the mortality of chicken embryos, and exerted a stronger antioxidant ability in offspring than sodium selenite (SS). Since previous studies also confirmed that Se deposition in eggs was positively correlated with maternal supplementation, this study aimed to directly investigate the antioxidant activities and underlying mechanisms of SS and SM on the chicken hepatocellular carcinoma cell line (LMH). The cytotoxicity results showed that the safe concentration of SM was up to 1000 ng/mL, while SS was 100 ng/mL. In Se treatments, both SS and SM significantly elevated mRNA stability and the protein synthesis rate of glutathione peroxidase (GPx) and thioredoxin reductase (TrxR), two Se-containing antioxidant enzymes. Furthermore, SM exerted protective effects in the H2O2-induced oxidant stress model by reducing free radicals (including ROS, MDA, and NO) and elevating the activities of antioxidative enzymes, which performed better than SS. Furthermore, the results showed that cotreatment with SM significantly induced apoptosis induced by H2O2 on elevating the content of Bcl-2 and decreasing caspase-3. Moreover, investigations of the mechanism revealed that SM might exert antioxidant effects on H2O2-induced LMHs by activating the Nrf2 pathway and enhancing the activities of major antioxidant selenoenzymes downstream. These findings provide evidence for the effectiveness of SM on ameliorating H2O2-induced oxidative impairment and suggest SM has the potential to be used in the prevention or adjuvant treatment of oxidative-related impairment in poultry feeds.

Two tributaries heterogeneous neural network based channel emulator for underwater visible light communication systems.

This paper proposes a novel two tributaries heterogeneous neural network (TTHnet) based channel emulator, which is suitable for both estimating single-carrier and multi-carrier modulated channels of underwater visible light communication (UVLC). Compared to traditional neural networks, the TTHnet channel emulator has only 1932 trainable parameters, which is only 0.8% of multilayer perceptron (MLP) based channel emulator and 1% of a convolutional neural network (CNN) based channel emulator. Furthermore, it provides a more accurate estimation of the UVLC channel and greater interpretability than MLP and CNN. The experiments in this paper use carrier-less amplitude/phase modulation (CAP) and discrete multi-tone modulation (DMT) as representative examples of single-carrier and multi-carrier modulation, respectively. The experiment proves that the TTHnet based channel emulator could effectively emulate the channel response of UVLC systems both in time and frequency domain. To the best of our knowledge, this is the first time that the single-carrier and multi-carrier modulated UVLC channel is emulated by the deep neural networks based channel emulator, which will effectively accelerate the research progress of UVLC and reduce research costs of UVLC systems.

Memory-controlled deep LSTM neural network post-equalizer used in high-speed PAM VLC system.

Linear and nonlinear impairments severely limit the transmission performance of high-speed visible light communication systems. Neural network-based equalizers have been applied to optical communication systems, which enables significantly improved system performance, such as transmission data rate and distance. In this paper, a memory-controlled deep long short-term memory (LSTM) neural network post-equalizer is proposed to mitigate both linear and nonlinear impairments in pulse amplitude modulation (PAM) based visible light communication (VLC) systems. Both 1.15-Gbps PAM4 and 0.9Gbps PAM8 VLC systems are successfully demonstrated, based on a single red-LED with bit error ratio (BER) below the hard decision forward error correction (HD-FEC) limit of 3.8 x 10-3. Compared with the traditional finite impulse response (FIR) based equalizer, the Q factor performance is improved by 1.2dB and the transmission distance is increased by one-third in the same experimental hardware setups. Compared with traditional nonlinear hybrid Volterra equalizers, the significant complexity and system performance advantages of using a LSTM-based equalizer is demonstrated. To the best of our knowledge, this is the first demonstration of using deep LSTM in VLC systems.

Determination of 226Ra Activity Using Gamma Spectrometry with 226Ra-222Rn Disequilibrium.

Radium-226 (Ra) activity is normally determined indirectly by gamma spectrometry, in particular by measuring the characteristic γ-ray emitted from its progeny (Pb and Bi) when Ra-Rn secular equilibrium is reached. This article describes a measurement method involving the measurement of Pb ingrowth. The activity of Ra determined by this method agrees with that measured after Ra-Rn equilibrium. The method of Pb ingrowth allows rapid and sufficiently accurate determination of Ra activity without the need to wait for Ra-Rn equilibrium.