Paxillin facilitates timely neurite initiation on soft-substrate environments by interacting with the endocytic machinery.

Neurite initiation is the first step in neuronal development and occurs spontaneously in soft tissue environments. Although the mechanisms regulating the morphology of migratory cells on rigid substrates in cell culture are widely known, how soft environments modulate neurite initiation remains elusive. Using hydrogel cultures, pharmacologic inhibition, and genetic approaches, we reveal that paxillin-linked endocytosis and adhesion are components of a bistable switch controlling neurite initiation in a substrate modulus-dependent manner. On soft substrates, most paxillin binds to endocytic factors and facilitates vesicle invagination, elevating neuritogenic Rac1 activity and expression of genes encoding the endocytic machinery. By contrast, on rigid substrates, cells develop extensive adhesions, increase RhoA activity and sequester paxillin from the endocytic machinery, thereby delaying neurite initiation. Our results highlight paxillin as a core molecule in substrate modulus-controlled morphogenesis and define a mechanism whereby neuronal cells respond to environments exhibiting varying mechanical properties

Quantum Impurity in Luttinger Liquid: Universal Conductance with Entanglement Renormalization

We study numerically the universal conductance of Luttinger liquids wire with a single impurity via the Muti-scale Entanglement Renormalization Ansatz (MERA). The scale invariant MERA provides an efficient way to extract scaling operators and scaling dimensions for both the bulk and the boundary conformal field theories. By utilizing the key relationship between the conductance tensor and ground-state correlation function, the universal conductance can be evaluated within the framework of the boundary MERA. We construct the boundary MERA to compute the correlation functions and scaling dimensions for the Kane-Fisher fixed points by modeling the single impurity as a junction (weak link) of two interacting wires. We show that the universal behavior of the junction can be easily identified within the MERA and argue that the boundary MERA framework has tremendous potential to classify the fixed points in general multi-wire junctions.Comment: 14 pages, 18 figure

Orbital density wave induced by electron-lattice coupling in orthorhombic iron pnictides

In this paper we explore the magnetic and orbital properties closely related to a tetragonal-orthorhombic structural phase transition in iron pnictides based on both two- and five-orbital Hubbard models. The electron-lattice coupling, which interplays with electronic interaction, is self-consistently treated. Our results reveal that the orbital polarization stabilizes the spin density wave (SDW) order in both tetragonal and orthorhombic phases. However, the ferro-orbital density wave (F-ODW) only occurs in the orthorhombic phase rather than in the tetragonal one. Magnetic moments of Fe are small in the intermediate Coulomb interaction region for the striped antiferromangnetic phase in the realistic five orbital model. The anisotropic Fermi surface in the SDW/ODW orthorhombic phase is well in agreement with the recent angle-resolved photoemission spectroscopy experiments. These results suggest a scenario that the magnetic phase transition is driven by the ODW order mainly arising from the electron-lattice coupling.Comment: 21 pages, 10 figure

Clinical effects research of the excision of pterygium combined with limbal epithelial autograft with conjunctival grafting on recurrent pterygium

AIM: To observe the clinical effects of the excision of pterygium combined with limbal epithelial autograft with conjunctival grafting on recurrent pterygium. <p>METHODS: Totally 84 patients(84 eyes)with first recurrent pterygium were allocated two groups: excision pterygium with limbal epithelial autograft with conjunctival(group A, 43 cases with 43 eyes)and excision of pterygium with conjunctival autograft(group B, 41 cases with 41 eyes), the post-operative follow-up period of 12 months, we analyzed the repair time of epithelium, tear break-up time(1 month and 3 months), Schirmer l test(1 month and 3 months), corneal fluorescence staining test(1 month and 3 months), and recurrent rate. <p>RESULTS: The group A had a shorter repair time of epithelium and lower recurrent rate, compared with the group B, which had statistically significant difference(<i>P</i><0.05), but there was no statistically significant difference in the tear break-up time, corneal fluorescence staining test and the Schirmer l test in 1 month and 3 months between the two groups(<i>P</i>>0.05). <p>CONCLUSION:Limbal epithelial autograft with conjunctival transplantation is a convenient, safe, effective method for the treatment of recurrent pterygium