Glucocorticoid Receptor β Acts As a Co-activator of T-Cell Factor 4 and Enhances Glioma Cell Proliferation

We previously reported that glucocorticoid receptor β (GRβ) regulates injury-mediated astrocyte activation and contributes to glioma pathogenesis via modulation of β-catenin/T-cell factor/lymphoid enhancer factor (TCF/LEF) transcriptional activity. The aim of this study was to characterize the mechanism behind cross-talk between GRβ and β-catenin/TCF in the progression of glioma. Here, we reported that GRβ knockdown reduced U118 and Shg44 glioma cell proliferation in vitro and in vivo. Mechanistically, we found that GRβ knockdown decreased TCF/LEF transcriptional activity without affecting β-catenin/TCF complex. Both GRα and GRβ directly interact with TCF-4, while only GRβ is required for sustaining TCF/LEF activity under hormone-free condition. GRβ bound to the N-terminus domain of TCF-4 its influence on Wnt signaling required both ligand- and DNA-binding domains (LBD and DBD, respectively). GRβ and TCF-4 interaction is enough to maintain the TCF/LEF activity at a high level in the absence of β-catenin stabilization. Taken together, these results suggest a novel cross-talk between GRβ and TCF-4 which regulates Wnt signaling and the proliferation in gliomas

Pairing symmetry and properties of iron-based high temperature superconductors

Pairing symmetry is important to indentify the pairing mechanism. The analysis becomes particularly timely and important for the newly discovered iron-based multi-orbital superconductors. From group theory point of view we classified all pairing matrices (in the orbital space) that carry irreducible representations of the system. The quasiparticle gap falls into three categories: full, nodal and gapless. The nodal-gap states show conventional Volovik effect even for on-site pairing. The gapless states are odd in orbital space, have a negative superfluid density and are therefore unstable. In connection to experiments we proposed possible pairing states and implications for the pairing mechanism.Comment: 4 pages, 1 table, 2 figures, polished versio

Layer-dependent transport properties in the Moir\'e of strained homobilayer transition metal dichalcogenides

Bilayer moir\'e structures have attracted significant attention recently due to their spatially modulated layer degrees of freedom. However, the layer-dependent transport mechanism in the moir\'e structures is still a problem to be explored. Here we investigate the layer-dependent transport properties regulated by the strain, the interlayer bias and the number of moir\'e periods in a strained moir\'e homobilayer TMDs nanoribbon based on low-energy efficient models. The charge carriers can pass perfectly through the scattering region with the moir\'e potential. While, it is noted that the overall transmission coefficient is mainly contributed from either intralayer or interlayer transmissions. The transition of transport mechanism between intralayer and interlayer transmissions can be achieved by adjusting the strain. The intralayer transmissions are suppressed and one of the interlayer transmissions can be selected by a vertical external electric field, which can cause a controllable layer polarization. Moreover, the staggered intralayer and interlayer minigaps are formed as the number of moir\'e periods increases in the scattering region due to the overlap of the wave functions in two adjacent moir\'e periods. Our finding points to an opportunity to realize layer functionalities by the strain and electric field.Comment: 6 pages, 4 figure

An Updated Search of Steady TeV γ−\gamma-Ray Point Sources in Northern Hemisphere Using the Tibet Air Shower Array

Using the data taken from Tibet II High Density (HD) Array (1997 February-1999 September) and Tibet-III array (1999 November-2005 November), our previous northern sky survey for TeV $\gamma-$ray point sources has now been updated by a factor of 2.8 improved statistics. From $0.0^{\circ}$ to $60.0^{\circ}$ in declination (Dec) range, no new TeV $\gamma-$ray point sources with sufficiently high significance were identified while the well-known Crab Nebula and Mrk421 remain to be the brightest TeV $\gamma-$ray sources within the field of view of the Tibet air shower array. Based on the currently available data and at the 90% confidence level (C.L.), the flux upper limits for different power law index assumption are re-derived, which are approximately improved by 1.7 times as compared with our previous reported limits.Comment: This paper has been accepted by hepn

Nanoscale anisotropic plastic deformation in single crystal GaN

Elasto-plastic mechanical deformation behaviors of c-plane (0001) and nonpolar GaN single crystals are studied using nanoindentation, cathodoluminescence, and transmission electron microscopy. Nanoindentation tests show that c-plane GaN is less susceptible to plastic deformation and has higher hardness and Young's modulus than the nonpolar GaN. Cathodoluminescence and transmission electron microscopy characterizations of indent-induced plastic deformation reveal that there are two primary slip systems for the c-plane GaN, while there is only one most favorable slip system for the nonplane GaN. We suggest that the anisotropic elasto-plastic mechanical properties of GaN are relative to its anisotropic plastic deformation behavior

Attacks on Telex Internet anticensorship system

As a typical router-redirecting based anticensorship system,Telex poses new challenges for Internet censors.To help common users evade Internet censorship,Telex employs network routers,rather than end-hosts,to relay network traffics to blocked destinations.The security of Telex from the censors' perspective is analyzed,and two kinds of active attacks aiming to break users' privacy are presented.The first is a kind of DoS attack,which exploits a security flaw of Telex handshake protocol.It can probabilistically identify the users who are using Telex,as well as break the availability of Telex.An improved handshake protocol to remedy the flaw is also proposed.The second is called TCP packets by-passing attack.Under that attacking scenario,censors make a small fraction of TCP packets from clients bypass the router and reach the cover site directly through asymmetric routing paths or IP tunnels,then determine whether a user is utiliz-ing Telex by observing the reaction of upstream traffic.The feasibility of bypassing attack has been testified by a series of experiments in a prototype environment.The bypassing attack is also applicable to other router-redirecting based anti-censorship systems

Valley polarization and valleyresistance in monolayer transition metal dichalcogenides superlattice

Manipulating the valley degree of freedom to encode information for potential valleytronic devices has ignited a new direction in solid-state physics. A significant, fundamental challenge in the field of valleytronics is how to generate and regulate valley-polarized currents by practical ways. Here, we discover a new mechanism of producing valley polarization in a monolayer transition metal dichalcogenides superlattice, in which valley-resolved gaps are formed at the supercell Brillouin zone boundaries and centers due to the intervalley scattering. When the energy of the incident electron is in the gaps, the available states are valley polarized, thus providing a valley-polarized current from the superlattice. We show that the direction and strength of the valley polarization may further be tuned by varying the potential applied the superlattice. The transmission can have a net valley polarization of 55% for a 4-period heterojunction. Moreover, such two valley filters in series may function as an electrostatically controlled giant valleyresistance device, representing a zero magnetic field counterpart to the familiar giant magnetoresistance device.Comment: 14 pages, 4 figure