Topological gauge theory, symmetry fractionalization, and classification of symmetry-enriched topological phases in three dimensions

Symmetry plays a crucial role in enriching topological phases of matter. Phases with intrinsic topological order that are symmetric are called symmetry-enriched topological phases (SET). In this paper, we focus on SETs in three spatial dimensions, where the intrinsic topological orders are described by Abelian gauge theory and the symmetry groups are also Abelian. As a series work of our previous research [Phys. Rev. B 94, 245120 (2016); (arXiv:1609.00985)], we study these topological phases described by twisted gauge theories with global symmetry and consider all possible topologically inequivalent "charge matrices". Within each equivalence class, there is a unique pattern of symmetry fractionalization on both point-like and string-like topological excitations. In this way, we classify Abelian topological order enriched by Abelian symmetry within our field-theoretic approach. To illustrate, we concretely calculate many representative examples of SETs and discuss future directions

Bergenin attenuates TNF-α-induced oxidative stress and inflammation in HaCaT cells by activating Nrf2 pathway and inhibiting NF-κB pathway

Purpose: To investigate the effect of bergenin in TNF-α-induced human immortalized keratinocytes.Methods: Human immortal keratinocyte cells (HaCaT) were incubated with tumor necrosis factor-α (TNF-α), and then treated with increasing concentrations of bergenin. Cell viability was determined using Cell Counting Kit-8 (CCK8), while oxidative stress and inflammation were evaluated using enzyme linked immunosorbent assay (ELISA).Results: Incubation with increasing concentrations of bergenin showed no significant effect on cell viability of HaCaT (p < 0.05). Tumor necrosis factor-α significantly induced up-regulation of interleukin (IL)-6 and IL-8 in HaCaT (p < 0.001), while bergenin significantly reduced the levels of IL-6 and IL-8 (p < 0.001). Bergenin also attenuated TNF-α-induced decrease in superoxide dismutase (SOD), as well as increase in malondialdehyde (MDA) and inducible nitric oxide synthase (iNOS). Protein expression of IκBα in HaCaT was decreased, while p-p65 and p-IκBα were increased by treatment with TNF-α. However, bergenin increased IκBα but decreased p-p65 and p-IκBα in TNF-α-induced HaCaT. Moreover, bergenin reduced Kelch-like ECH-associated protein 1 (Keap1), while enhancing transcription factor NF-E2 p45-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) in TNF-α-induced HaCaT.Conclusion: Bergenin exerts antioxidant and anti-inflammatory effects on TNF-α-induced HaCaT by activating Nrf2 pathway and inactivating NF-κB pathway. Therefore, bergenin is a potential agent for the treatment of psoriasis

Topological energy gaps in the [111]-oriented InAs/GaSb and GaSb/InAs core-shell nanowires

The [111]-oriented InAs/GaSb and GaSb/InAs core-shell nanowires have been studied by the $8\times 8$ Luttinger-Kohn $\vec{k}\cdot\vec{p}$ Hamiltonian to search for non-vanishing fundamental gaps between inverted electron and hole bands. We focus on the variations of the topologically nontrivial fundamental gap, the hybridization gap, and the effective gap with the core radius and shell thickness of the nanowires. The evolutions of all the energy gaps with the structural parameters are shown to be dominantly governed by quantum size effects. With a fixed core radius, a topologically nontrivial fundamental gap exists only at intermediate shell thicknesses. The maximum gap is $\sim 4.4$ meV for GaSb/InAs and $\sim 3.5$ meV for InAs/GaSb core-shell nanowires, and for the GaSb/InAs core-shell nanowires the gap persists over a wider range of geometrical parameters. The intrinsic reason for these differences between the two types of nanowires is that in the shell the electron-like states of InAs is more delocalized than the hole-like state of GaSb, while in the core the hole-like state of GaSb is more delocalized than the electron-like state of InAs, and both features favor stronger electron-hole hybridization. Since similar features of the electron- and hole-like states have been found in nanowires of other materials, it could serve as a common rule to put the hole-like state in the core while the electron-like state in the shell of a core-shell nanowire to achieve better topological properties.Comment: 10 pages, 10 figure

Measuring the similarity of PML documents with RFID-based sensors

The Electronic Product Code (EPC) Network is an important part of the Internet of Things. The Physical Mark-Up Language (PML) is to represent and de-scribe data related to objects in EPC Network. The PML documents of each component to exchange data in EPC Network system are XML documents based on PML Core schema. For managing theses huge amount of PML documents of tags captured by Radio frequency identification (RFID) readers, it is inevitable to develop the high-performance technol-ogy, such as filtering and integrating these tag data. So in this paper, we propose an approach for meas-uring the similarity of PML documents based on Bayesian Network of several sensors. With respect to the features of PML, while measuring the similarity, we firstly reduce the redundancy data except information of EPC. On the basis of this, the Bayesian Network model derived from the structure of the PML documents being compared is constructed.Comment: International Journal of Ad Hoc and Ubiquitous Computin