The dispersion of linear waves in a uniform cold quantum plasma is derived using the quantum hydrodynamic equations with the magnetic field of the Wigner-Poisson system. The dispersion of the Langmuir wave becomes whistler-like due to quantum effects and, therefore, the Langmuir wave can propagate in a cold plasma. It is also found that quantum effects do not affect the dispersion of the left-handed, right-handed, and ordinary waves.

Terahertz (THz) communication has always been considered as a potential solution for ``communication blackout'' during aircraft reentry. In this article, the propagation characteristics of the THz wave in the realistic plasma sheath during the whole reentry process are studied by solving the fluid model and the THz transmission model. As a result, the electron number density and collision frequency decrease with the increase of reentry height and antenna position. And the attenuation of the THz wave decreases with the increase of the electromagnetic (EM) wave frequency, reentry height, and antenna position. Finally, two THz communication schemes to mitigate or avoid the ``communication blackout'' problem for the whole reentry process were discussed. One is for uncertain antenna position and reentry height, selecting EM waves with a frequency above 0.35 THz for communication. The other is to install the antenna near the bottom of the vehicle (L = - 1.0 m in this article) with a wave frequency above 0.12 THz.

Bacteria killing behavior based on physical effects is preferred for biomedical implants because of the negligible associated side effects. However, our current understanding of the antibacterial activity of nanostructures remains limited and, in practice, nanoarchitectures that are created on orthopedics should also promote osteogenesis simultaneously. In this study, tilted and vertical nanolamellar structures are fabricated on semi-crystalline polyether-ether-ketone (PEEK) via argon plasma treatment with or without pre-annealing. The two types of nanolamellae can physically kill the bacteria that come into contact with them, but the antibacterial mechanisms between the two are different. Specifically, the sharp edges of the vertically aligned nanolamellae can penetrate and damage the bacterial membrane, whereas bacteria are stuck on the tilted nanostructures and are stretched, leading to eventual destruction. The tilted nanolamellae are more desirable than the vertically aligned ones from the perspective of peri-implant bone regeneration. Our study not only reveals the role of the arrangement of nanostructures in orthopedic applications but also provides new information about different mechanisms of physical antibacterial activity.

Winter jujube (Ziziphus jujuba Mill. cv. Dongzao) is a very popular horticultural fruit worldwide, which contains a high number of bioactive compounds. Nevertheless, jujube is perishable by microbial contamination and has a short shelf life under non-controlled conditions. Cold atmospheric plasma (CAP) presents a great potential for food sterilization, maintain postharvest quality, and prolonged storage time. Herein, this study investigated the potential effect of CAP with different exposure times (0, 5, 10, and 20 min) on the physicochemical and biochemical changes in jujube during 15-day storage at 4°C and 90% relative humidity (RH). The results showed that CAP treatment could obviously delay ripening, but displayed no effects on the speed of weight loss and moisture content. Meanwhile, the total native aerobic bacterial count in each jujube group was restrained during whole storage. However, CAP treatment showed a time-dependent manner to improve gene expression (PAL, 4CL, DFR, ANS, LAR, and ANR) related to phenolic biosynthesis. As compared to other groups, 20-min CAP treatment can keep or increase total phenolic content (TPC), maintain antioxidant activity, and reduce oxidative damage. Furthermore, the hydrogen peroxide (H₂O₂) and malondialdehyde (MDA) content in jujube during middle storage were visibly reduced by 20-min CAP treatment. All in all, our findings concluded that appropriate CAP exposure time can be a promising candidate for the postharvest preservation of jujube.