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Migmatites are widespread in the North Dabie ultrahigh-pressure metamorphic terrane (NDT) of Dabie orogen, East China. Idiomorphic and poikilitic amphibole grains in both leucosome and melanosome contain inclusions of plagioclase, quartz and biotite, suggesting formation of leucosome by fluid-present melting of biotite + plagioclase + quartz-bearing protoliths at P = 5-7 kbar, T = 700-800°C. Precise SIMS zircon U-Pb dating indicates that migmatization of Dabie orogen initiated at ~ 140 Ma and lasted for ~ 10 Ma, coeval with the formation of low-[Mg.sup.#] adakitic intrusions in Dabie orogen. Based on mineralogical, petrographic and geochemical data, leucosomes in NDT can be subdivided into three groups. (1) High [La/Yb.sub.(N)]-Medium Sr/Y group (Group I), whose high [Dy/Yb.sub.(N)] but medium Sr/Y ratios are caused by amphibole and plagioclase residual during partial melting of dioritic to granodioritic gneisses. (2) Low [La/Yb.sub.(N)]-Low Sr/Y group (Group II), whose flat HREE patterns are produced by entrainment of peritectic amphiboles into melts derived from partial melting of dioritic gneiss. (3) High [La/Yb.sub.(N)]-High Sr/Y and [Eu.sup.#] group (Group III), whose extremely high Sr and Eu but low other REE concentrations are caused by accumulation of plagioclase and quartz. Although Group I and III fall in the adakitic fields on [La/Yb.sub.(N)]-[Yb.sub.(N)] and Sr/Y-Y diagrams, they are chemically distinct from contemporary high-pressure adakitic intrusions in Dabie orogen in a series of geochemical indexes, for example, lower [Dy/Yb.sub.(N)] and/or Sr/Y ratios at given [La/Yb.sub.(N)] ratio, lower Sr/CaO ratios, lower Rb concentration but higher K/Rb ratios. Therefore, leucosomes are produced by anatexis of the exhumed ultrahigh-pressure metamorphic rocks at middle crustal level, instead of partial melting of thickened lower crust with garnet-rich and plagioclase-poor residual. The coeval occurrence of migmatites and high-pressure adakitic intrusions in Dabie orogen indicates large-scale partial melting of middle to thickened lower crustal column in the early Cretaceous. The required heat source may be the mantle heat conducting through the lithospheric mantle whose lower parts have been convectively removed. Keywords Dabie orogen * Migmatite * Middle crustal melting * Adakite * Lithosphere thinning, Introduction Partial melting of middle-lower crust is a common phenomenon in many ancient and modern orogenic belts (e.g., Sawyer et al. 2011). Its initiation is a combined response to the [...]

A new Ti2AlNb-based alloy with the composition of Ti-22Al-25Nb-1Mo-1V-1Zr-0.2Si (at%) was fabricated in the sequence of arc melting, forging, solid solution and aging. Present paper focuses on the effects of aging temperatures (700, 750, 800, 850 and 900 °C) on microstructure, room-temperature tensile properties as well as tensile properties at 650 °C and creep properties at 650 °C/150 MPa. It is obvious that the aging treatment promotes the precipitation of O lathes from B2 matrix. With aging temperature increasing, the content of O phase decreases and its size increases gradually, which leads to the decrease in tensile strengths both at room temperature and 650 °C and a little increase in ductility. For creep properties, the sample aged at 700 °C shows the best creep resistance due to its extremely high O phase content. Aging at 800 °C leads to the decrease in the content of O phase and softening of the alloy significantly. However, with aging temperature further increasing from 800 to 900 °C, the precipitated O phase will be coarsened gradually, which strengthens the alloy again. [ABSTRACT FROM AUTHOR]

The oxidation behavior of a novel multi-element alloyed Ti2AlNb-based alloy (Ti-22Al-25Nb-1Mo-1V-1Zr-0.2Si) was studied in the temperature range of 650-850 °C. X-ray diffraction (XRD) and scanning electron microscopy (SEM) equipped with an energy-dispersive spectroscopy (EDS) were used to identify the phase constituents and microstructure of the scales formed on the specimens after oxidation at different temperatures. Isothermal oxidation tests show that the oxidation rate of the alloyed Ti2AlNb-based alloy is obviously reduced at all temperatures, and the mass gains are very low for this alloy in comparison with those of Ti-22Al-25Nb alloy. The alloying elements Mo, V, Zr and Si have an obvious affect on the oxidation products of the alloys. The improved oxidation resistance for the alloy is ascribed to the introduction of Mo, V, Zr and Si elements, which are beneficial to the selective oxidation of Al to form protective oxides while are disadvantage of the formation of poor oxidation resistance oxides such as AlNbO4. [ABSTRACT FROM AUTHOR]

Brain-derived neurotrophic factor (BDNF) plays important roles in neural stem cell (NSC) growth. In this study, we investigated whether BDNF exerts its neurotrophic effects through the Wnt/β-catenin signaling pathway in human embryonic spinal cord NSCs (hESC-NSCs)in vitro. We found an increase in hESC-NSC growth by BDNF overexpression. Furthermore, expression of Wnt1, Frizzled1 and Dsh was upregulated, whereas GSK-3β expression was downregulated. In contrast, hESC-NSC growth was decreased by BDNF RNA interference. BDNF, Wnt1 and β-catenin components were all downregulated, whereas GSK-3β was upregulated. Next, we treated hESC-NSCs with 6-bromoindirubin-3′-oxime (BIO), a small molecule inhibitor of GSK-3β. BIO reduced the effects of BDNF upregulation/downregulation on the cell number, soma size and differentiation, and suppressed the effect of BDNF modulation on the Wnt signaling pathway. Our findings suggest that BDNF promotes hESC-NSC growthin vitrothrough crosstalk with the Wnt/β-catenin signaling pathway, and that this interaction may be mediated by GSK-3β. [ABSTRACT FROM PUBLISHER]

Shielding effectiveness of electromagnetic shielded enclosure would be decreased by blast shocks. An electromagnetic shielded enclosure with the shock isolator with own patented technology is designed and constructed. The field blasting and shielding performance tests are conducted to study the effect of blast shock on the the shielding effectiveness of electromagnetic shielded enclosure with integral shock isolation. The results show that the vibration acceleration of electromagnetic shielded enclosure with integral shock isolation is only 18 m/s² although the input vibration acceleration peak is up to 115 m/s² under the blast shocks of 160 kg cumulative charge. This means that the integral shock isolation effectively reduces the impact of blast shock on electromagnetic shielded enclosure. The electromagnetic shielded enclosure meets the requirement of Grade I . [ABSTRACT FROM AUTHOR]

A Pichia pastoris (P. pastoris) cell surface display system of Bombyx mori acetylcholinesterase (BmAChE) was constructed and its bioactivity was studied. The modified Bombyx mori acetylcholinesterase gene (bmace) was fused with the anchor protein (AGα1) from Saccharomyces cerevisiae and transformed into P. pastoris strain GS115. The recombinant strain harboring the fusion gene bmace-AGα1 was induced to display BmAChE on the P. pastoris cell surface. Fluorescence microscopy and flow cytometry assays revealed that the BmAChE was successfully displayed on the cell surface of P. pastoris GS115. The enzyme activity of the displayed BmAChE was detected by the Ellman method at 787.7 U/g (wet cell weight). In addition, bioactivity of the displayed BmAChE was verified by inhibition tests conducted with eserine, and with carbamate and organophosphorus pesticides. The displayed BmAChE had an IC50 of 4.17×10−8 M and was highly sensitive to eserine and five carbamate pesticides, as well as seven organophosphorus pesticides. Results suggest that the displayed BmAChE had good bioactivity. [ABSTRACT FROM AUTHOR]

A Pichia pastoris (P. pastoris) cell surface display system of Bombyx mori acetylcholinesterase (BmAChE) was constructed and its bioactivity was studied. The modified Bombyx mori acetylcholinesterase gene (bmace) was fused with the anchor protein (AGα1) from Saccharomyces cerevisiae and transformed into P. pastoris strain GS115. The recombinant strain harboring the fusion gene bmace-AGα1 was induced to display BmAChE on the P. pastoris cell surface. Fluorescence microscopy and flow cytometry assays revealed that the BmAChE was successfully displayed on the cell surface of P. pastoris GS115. The enzyme activity of the displayed BmAChE was detected by the Ellman method at 787.7 U/g (wet cell weight). In addition, bioactivity of the displayed BmAChE was verified by inhibition tests conducted with eserine, and with carbamate and organophosphorus pesticides. The displayed BmAChE had an IC50 of 4.17×10−8 M and was highly sensitive to eserine and five carbamate pesticides, as well as seven organophosphorus pesticides. Results suggest that the displayed BmAChE had good bioactivity. [ABSTRACT FROM AUTHOR]