Angiogenesis in Differentiated Placental Multipotent Mesenchymal Stromal Cells Is Dependent on Integrin α5β1

Human placental multipotent mesenchymal stromal cells (hPMSCs) can be isolated from term placenta, but their angiogenic ability and the regulatory pathways involved are not known. hPMSCs were shown to express integrins αv, α4, α5, β1, β3, and β5 and could be induced to differentiate into cells expressing endothelial markers. Increases in cell surface integrins α5 and β1, but not α4, αvβ3, or αvβ5, accompanied endothelial differentiation. Vascular endothelial growth factor-A augmented the effect of fibronectin in enhancing adhesion and migration of differentiated hPMSC through integrin α5β1, but not αvβ3 or αvβ5. Formation of capillary-like structures in vitro from differentiated cells was inhibited by pre-treatment with function-blocking antibodies to integrins α5 and β1. When hPMSCs were seeded onto chick chorioallantoic membranes (CAM), human von Willebrand factor-positive cells were observed to engraft in the chick endothelium. CAMs transplanted with differentiated hPMSCs had a greater number of vessels containing human cells and more incorporated cells per vessel compared to CAMs transplanted with undifferentiated hPMSCs, and overall angiogenesis was enhanced more by the differentiated cells. Function-blocking antibodies to integrins α5 and β1 inhibited angiogenesis in the CAM assay. These results suggest that differentiated hPMSCs may contribute to blood vessel formation, and this activity depends on integrin α5β1

25th Annual Computational Neuroscience Meeting: CNS-2016

Abstracts of the 25th Annual Computational Neuroscience Meeting: CNS-2016 Seogwipo City, Jeju-do, South Korea. 2–7 July 201

Diffusion characteristics in the Cu-Ti system

The formation and growth of intermetallic compounds by diffusion reaction of Cu and Ti were investigated in the temperature range 720-860 degrees C using bulk diffusion couples. Only four, out of the seven stable intermediate compounds of the Cu-Ti system, were formed in the diffusion reaction zone in the sequence CuTi, Cu4Ti, Cu4Ti3 and CuTi2. The activation energies required for the growth of these compounds were determined. The diffusion characteristics of Cu4Ti, CuTi and Cu4Ti3 and Cu(Ti) solid solution were evaluated. The activation energies for diffusion in these compounds were 192.2, 187.7 and 209.2 kJ mol(-1) respectively, while in Cu(Ti), the activation energy increased linearly from 201.0 kJ mol(-1) to 247.5 kJ mol(-1) with increasing concentration of Ti, in the range 0.5-4.0 at.%. The impurity diffusion coefficient of Ti in Cu and its temperature dependence were also estimated. A correlation between the impurity diffusion parameters for several elements in Cu matrix has been established

Stability of microstructure and its evolution during solid-state annealing of Al(2)O(3)-Inconel 600 brazed couples

The stability of the microstructure of alumina-Inconel 600 brazed joints was investigated under simulated in-service conditions by subjecting them to prolonged heat treatment at 400 and 560 degrees C. The evolution of the microstructure and microchemistry of the brazing zone was examined using extensive microanalysis of the constituent phases. The layered structure of the brazing zone transformed to homogeneous, near-equilibrium, two-phase microstructure after heat treatment at 560 C. Solid-state interdiffusion was identified as a primary factor responsible for such copious modification of the microstructure. Intermediate temperature heat treatment at 400 degrees C revealed that the mechanism of transformation of the microstructure was globulization of the Ni overlayer and dissolution of Mo from the metallization layer into the Ni-rich phase. The migration behavior of each of the elements, in response to heat treatment, was analyzed. Cr was found to diffuse out of Inconel and form a layer of Cr(2)O(3) at the alumina-brazing alloy interface. The bond strength of the interface was high enough to cause cohesive failure in the alumina side of the joints. (C) 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved

Microstructural evolution during reactive brazing of alumina to Inconel 600 using Ag-based alloy

A metal ceramic bonding process was developed to produce vacuum tight alumina Inconel 600 joints using an Ag-based active metal brazing alloy that can withstand continuous operating temperature up to 560 degrees C. The microstructure and microchemistry of the braze zone was examined using extensive microanalysis of the constituent phases and a mechanism for the interfacial reactions responsible for the bonding is proposed. Prolonged heat treatment at 400 and 560 degrees C under simulated in-service conditions revealed that the microstructure of braze zone of the joints was stable and maintained leak-tightness and strength. The bond strength of the interface was high enough to cause failure in the alumina side of the joints. Failure of the joints was caused by initiation of crack on the surface of alumina as a result of high tensile residual stress adjacent to the metal ceramic interface. (C) 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved