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Cold atmospheric pressure plasma is receiving attention in biomedical treatment for its non-thermal, dry-type, and high-efficiency disinfection effects on bacteria, fungi, and viruses, compared to typical sterilization methods, such as pasteurization, chemical solutions, and ultraviolet radiation. There are great demands of plasma decontamination on the surface of complex 3D objects, with the request of large coverage, convenience, and uniformity, which still remains a challenge for the current plasma devices. In this work, a flexible thin-layer plasma source for sterilization is developed based on a polyimide substrate, and its plasma generation process is characterized by experiment and simulation. The influences of bending deformation are studied and evaluated by electrical waveforms, heat radiation, and ozone production, of which the mechanisms are further explained. Results illustrate that the variation in electron impact ionization induced by different curvatures is the main cause leading to the change in microparticle production, thus affecting the macroscopic properties of plasmas. Activations of the plasma sterilizer for 30 and 120 s reduce both S. aureus and P. aeruginosa on the flat surface by around 2.5 and 5 log colony forming units (CFU). However, the plasma sterilization effect decreases with an extent of about 1 log CFU when treating the curved surface, while being regained after conforming the plasma sterilizer to the curved surface. This kind of plasma generator offers significant flexibility and efficacy, being promising for the treatment of objects with irregular surfaces in future plasma biomedicine and material processing. [ABSTRACT FROM AUTHOR]

The addition of active trace components to non-thermal plasmas effectively enhances their chemical activity and has attracted considerable academic attention in the plasma community. It is essential to quantitatively estimate the effect of active addition on the properties of the plasma–surface interaction (PSI). In this study, we focus on the fundamental properties of dynamic surface charge deposited by a He-atmospheric pressure plasma jet (APPJ) with 0%–2% CF4 additive. The charge distribution is measured by a reflective optical measurement platform based on linear electro-optic effect, and is calculated with surface charge density inversion algorithm. Results show that a higher CF4 concentration can shrink the region of surface charge accumulation. Polarity effect is observed in aspects of maximum charge density when the CF4 concentration gradually rises. The negative charge deposition is suppressed by the addition of CF4, nearly disappearing at 2% concentration. While the maximum density of positive charge rises to ∼25 nC cm−2 at 0.5% CF4 before it decreases to ∼10 nC cm−2. The dispersions of total surface charge at 0.5% and 1.5% additives indicate the unstable periodic bombardment of ionization waves in He/CF4 APPJ. The double effect of CF4 additive on the surface charges by He-APPJ is also discussed. These results provide fresh and deep insights into the interaction between dielectric surface modification and ionization waves that occurs in other plasmas processing fed with composite gases. [ABSTRACT FROM AUTHOR]

The incidence of depression is increasing day by day, and its pathogenesis is characterized by complexity and high recurrence rate. In addition, the pathogenesis has not been elucidated. There are significant differences in the reference indicators between rat and mouse models of different strains. As the experimental modeling of depression is easily affected by gender and modelling methods, it is necessary to standardize the selection of rat and mouse strains for experimental research. Although the widely used rat and mouse models of depression can meet the research on most depression diseases, with the in-depth study of component targets of traditional Chinese medicine (TCM) and the development of diagnosis and treatment of TCM dialectics, the improvement and maturity of the depression animal model that is in line with TCM syndrome classification will have more research values for the basic research of depression in Chinese medicine. Therefore, we summarize and analyze the characteristics of different strains of rats and mice based on contemporary literature in this review, in order to provide a more powerful theoretical basis for the basic research of syndromes on TCM treatment of depression. [ABSTRACT FROM AUTHOR]

In the field of face recognition, when the training samples and test samples are subject to severe noise pollution, the performance of the traditional subspace learning and the classical sparse representation (SRC) will drop sharply. In addition, the method based on sparse representation also faces the problem of computational complexity. In order to alleviate those problems, an occlusion face recognition method based on discriminating low-rank matrix recovery and collaborative representation is proposed. Firstly, the low-rank matrix recovery can recover the clean training samples with low-rank structure from the contaminated training samples and the structural non-correlation constraints can improve the discriminating ability of the recovered data effectively. Secondly, by learning the low-rank projection matrix between the original contaminated data and the recovered low-rank data, the contaminated test samples are projected into the corresponding low dimensional subspace to perform its correction. Finally, the modified test samples are classified by the collaborative representation classification method (CRC) to obtain the final recognition result. Experimental results on Extended Yale B and AR databases show that the proposed method has better recognition performance in occlusion face recognition. [ABSTRACT FROM AUTHOR]