RESUMO
The identification of topological superconductors usually involves searching for in-gap modes that are protected by topology. However, in current experimental settings, the smoking-gun evidence of these in-gap modes is still lacking. In this Letter, we propose to support the distinction between two-dimensional conventional s-wave and topological p-wave superconductors by above-gap transport signatures. Our method utilizes the emergence of Tomasch oscillations of quasiparticles in a junction consisting of a superconductor sandwiched between two metallic leads. We demonstrate that the behavior of the oscillations in conductance as a function of the interface barriers provides a distinctive signature for s-wave and p-wave superconductors. Specifically, the oscillations become weaker as the barrier strength increases in s-wave superconductors, while they become more pronounced in p-wave superconductors, which we prove to be a direct manifestation of the pairing symmetries. Our method can serve as a complimentary probe for identifying some classes of topological superconductors through the above-gap transport.
RESUMO
To investigate the impact and potential mechanisms of extracts from different parts of Liparis nervosa on neuroinflammation by lipopolysaccharide(LPS)-induced BV-2 microglial cells. The materials of L. nervosa were subjected to crushing, ethanol extraction, and concentration to obtain an alcohol extract. Subsequently, the extract was further extracted to obtain petroleum ether extract, ethyl acetate extract, N-butanol extract, and aqueous phase extract. The ethyl acetate extract was separated into distillate(1)-(6)using D101 macroporous resin column chromatography. The experiment was divided into control group, LPS model group, L. nervosa extract group, and LPS + L. nervosa group. LPS was utilized to induce a neuroinflammatory cell model in BV-2 microglial cells. The Griess test was utilized for detecting the production of nitric oxide(NO) in the cell supernatant. Cell viability was detected by MTT assay. The release of interleukin-6(IL-6) and tumor necrosis factor alpha(TNF-α) in the cell supernatant was quantified using ELISA.RT-qPCR was utilized to assess the m RNA levels of pro-inflammatory cytokines inducible nitric oxide synthase(iNOS), cyclooxygenase-2(COX-2), interleukin( IL)-6, IL-1ß, and TNF-α. The protein expression of i NOS, COX-2, nuclear factor kappa-B p65(p65), p-p65, extracellular signal-regulated kinase(ERK), p-ERK, c-jun N-terminal kinase(JNK), p-JNK, p38 mitogen-activated protein kinase(p38), and p-p38 MAPK(p-p38) were also evaluated by Western blot. The chemical composition of active substances in L. nervosa was analyzed using the UHPLC-Q-Exactive Orbitrap technology and literature comparison. Our findings indicate that extracts from different parts of L. nervosa exhibit a significant reduction in the release of NO from LPS-induced BV-2 microglial cells.Specifically, the ethyl acetate extract demonstrates the most notable inhibitory effect without causing cell toxicity. Additionally, the distillate(6) extracted from the ethyl acetate exhibits a reduction in the m RNA and protein levels of i NOS, COX-2, IL-6, IL-1ß, and TNF-α in a dose-dependent manner, and it inhibits the protein expression of p-p65, p-ERK, p-p38, and p-JNK in LPS-induced BV-2 microglial cells. A total of 79 compounds in the distillate(6) were identified by mass spectrometry, including 12 confirmed compounds with anti-inflammatory effects. This study confirmed the remarkable efficacy of L. nervosa extract in the treatment of neuroinflammation, which may be achieved through the inhibition of NF-κB and MAPK signaling pathways.