Co/C Nanocomposites with Tunable Condensed States Induced by Conformation-Mediated Strategy for Electromagnetic Wave Absorption.

The strategic regulation of condensed state structures in multicomponent nanomaterials has emerged as an effective approach for achieving controllable electromagnetic (EM) properties. Herein, a novel conformation-mediated strategy is proposed to manipulate the condensed states of Co and C, as well as their interaction. The conformation of polyvinylpyrrolidone molecules is adjusted using a gradient methanol/water ratio, whereby the coordination dynamic equilibrium effectively governs the deposition of metal-organic framework precursors. This process ultimately influences the combined impact of derived Co and C in the resulting Co/C nanocomposites post-pyrolysis. The experimental results show that the condensed state structure of Co/C nanocomposites transitions from agglomerate state → to biphasic compact state → to loose packing state. Benefiting from the tunable collaboration between interfacial polarization and defects polarization, and the appropriate electrical conductivity, the diphasic compact state of Co/C nanocomposites achieves an effective absorbing bandwidth of 7.12 GHz (2.1 mm) and minimum reflection loss of -32.8 dB. This study highlights the significance of condensed state manipulation in comprehensively regulating the EM wave absorption characteristics of carbon-based magnetic metal nanocomposites, encompassing factors such as conductivity loss, magnetic loss, defect polarization, and interface polarization.

Tamoxifen Prevents D-galactosamine/Lipopolysaccharide-Induced Murine Acute Hepatic Failure through Inhibition of Oxidative Stress and Mmd-2 Upregulation.

Oxidative stress is considered one of the major mechanisms underlying lipopolysaccharide (LPS)-induced acute liver failure (ALF). Tamoxifen has been reported to ameliorate LPS-induced ALF via the induction of monocyte to macrophage differentiation-associated 2 (Mmd-2). Whether antioxidant effects are involved remains unknown. Mice were given tamoxifen (TAM) once a day for 3 days. Twelve hours later, d-galactosamine (GaIN) and LPS were injected intraperitoneally to induce ALF. N-Acetylcysteine (NAC) was administered immediately after ALF induction as a positive control. The results showed that serum transaminases increased and hepatic antioxidants decreased significantly in the model group. ALF was alleviated markedly by TAM or NAC treatment. This demonstrated that ALF may be associated with excessive oxidative stress caused by decreased expression of antioxidant enzymes. Both TAM and NAC increased the levels and activity of these antioxidant enzymes significantly (p < 0.05). Hepatic Mmd-2 expression was downregulated in the control group while remaining stable or exhibiting elevated levels in the TAM or NAC groups. The results indicate that TAM may protect mice from GaIN/LPS-induced ALF through increased activity of antioxidant enzymes and upregulation of Mmd-2 expression.