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Active manipulation of Fano resonance at visible and near-IR wavelengths in metal nanodevices is one of the important challenges for applications such as chemical and biological sensing. Here, we theoretically research an active manipulation of Fano resonance at visible and near-IR wavelengths in gold plasmonic nanodevices with graphene. The surface plasmon resonance of the gold plasmonic nanodevice with graphene has three resonance peaks, and this can be explained by the distribution of the electric field in the nanodevice. The Fano resonance wavelength of the gold plasmonic nanodevice with graphene has a significant blue-shift compared with the gold nanodevices without graphene. Moreover, the Fano resonance depends on the length and position of Au nanorods and the environment refractive index. The figure of merit of the gold nanodevice with graphene can be as high as 44.1, which makes the system suitable for high sensitivity applications. Finally, we actively manipulate the absorption spectrum and the reflected light phase through changing the Fermi energy of graphene. These results suggest an original method for the design of an actively manipulated Fano resonance nanodevice.

Controllable random lasers based on two-dimensional (2D) random gain systems with nematic liquid crystals are investigated by using the finite-difference time-domain (FDTD) methods. The dependence of random lasers on the scattering strength of nematic liquid crystals is studied. The results show that the random laser characteristics including the pump threshold, the emission intensity and the number of laser modes can be controlled by varying the pump rates, the filling fraction of nematic liquid crystals, and the included angle between the polarization direction of pump beam and the director of nematic liquid crystals. To achieve the optimal random lasers, the polarization direction of pump beam should be parallel to the director of nematic liquid crystals.

The atmospheric pressure plasma jet (APPJ) has attracted the attention of many researchers from multiple disciplines in recent years because its emissions include multiple types of reactive nitrogen species (RNS) and reactive oxygen species (ROS). Our previous study has shown the cytoprotective effect of the APPJ against oxidative stress-induced injuries. The aim of the present study is to provide a detailed in vitro treatment protocol regarding the neuroprotective applications of helium APPJs on glucose deprivation-induced injury in SH-SY5Y cells. The SH-SY5Y human neuroblastoma-derived cell line was maintained in RPMI 1640 medium supplemented with 15% fetal calf serum. The culture medium was then changed to RPMI 1640 without glucose before APPJ treatment. After a 1 h incubation in a cell incubator, cell viability was determined using Cell Counting Kit 8. The results showed that, compared to the glucose deprivation group, cells treated with APPJ exhibited significantly increased cell viability in a dose-dependent manner, with 8 s/well observed as an optimal dose. Meanwhile, helium flow had no effect on the glucose deprivation-induced cell impairment. Our results indicated that APPJ could be potentially used as a treatment method for the diseases in the central nervous system related to glucose deprivation. This protocol could also be used as a cytoprotective application for other cells with different impairments, but the cell culture and APPJ treatment conditions should be readjusted, and the treatment dose must be relatively low.

Atmospheric pressure plasma jet (APPJ) has shown excellent potential prospects in biomedical applications, based on the production of reactive oxygen species and reactive nitrogen species (RNS) from APPJ emissions. The current research focused on the protective effect of APPJ on oxygen and glucose deprivation (OGD)-induced cell death in both the H9C2 cardiac myoblast cell line, a frequently used cardiac cell line in cardioprotective studies, and primary neonatal rat cardiomyocytes (NRCMs). Cells were treated with APPJ for different durations, cultured for 6 h and then subjected to OGD for 18 h before their use in assays. We found that APPJ treatment could maintain H9C2 cell viability and reduce cell apoptosis in a dose-dependent manner in cells subjected to the OGD conditions. To confirm the cardioprotective effect of APPJ on primary NRCM, we first identified the 'safe dose' of APPJ treatment by evaluating the cytotoxicity of APPJ on primary NRCMs in normal culture conditions. Under the 'safe dose' of APPJ treatment, we also found that the APPJ treatment could maintain NRCM viability under OGD conditions and reduce CK-MB and cTnI release from cardiomyocytes. Further studies revealed that the cytoprotective effect of APPJ may be related to NO production induced by APPJ treatment. Our results gave the first evidence of the cardiotoxicity and cytoprotective effect of APPJ on cardiomyocytes against OGD injury, and furthermore, contributed to new insights into the potential medical applications of plasma in cardiovascular diseases.

Atmospheric pressure plasma jet (APPJ) has recently been the focus of cytoprotective research due to the physiological roles of ROS and RNS. In the current study, we investigated the effect of APPJ treatment on the hypoxia (1% oxygen) induced cell injuries. SH-SY5Y cells were treated by APPJ for different duration and incubated in normoxic condition (20% oxygen) for 5 h followed by 24 h hypoxia treatment. Cell viability was evaluated by lactate dehydrogenase (LDH) release and further monitored using the electric cell-substrate impedance sensing (ECIS) system after APPJ treatment. Results showed that APPJ could reduce cell injuries after 24 h hypoxia, which was consistent with the ECIS results. Furthermore, extracellular NO and H2O2 production was significantly increased with the APPJ treatment. It was also interesting to find that APPJ treatment reduced SH-SY5Y cells proliferation in the hypoxic microenvironment during the first 20 h of hypoxia. Although more work was still need to clarify whether the cell viability maintenance was related to the cell proliferation during hypoxia, our results provide the first evidence of real-time cell viability changes after APPJ treatment under both normoxic and hypoxic conditions, which could provide evidence for the neuroprotective applications of APPJ.