ALBERT

Description: An integrated study of U-Pb ages and trace elements was carried out for titanite and zircon from ultrahigh-pressure (UHP) metagranites in the Sulu orogen, east-central China. The results provide constraints on the composition of metamorphic fluids during the exhumation of deeply subducted continental crust. Titanite has two domain types based on REE patterns and trace element variations, Ttn-I and Ttn-II, respectively. These two domains show indistinguishable U-Pb ages of 232±14 to 220±8 Ma, in general agreement with anatectic zircon U-Pb ages of 223±4 to 219±2 Ma for the partial melting event during early exhumation. The Ttn-I domains have significantly higher REE, Th, Ta and Sr, and higher Th/U ratios than the Ttn-II domains, indicating that the two domains have grown from metamorphic fluids with different compositions. For the Ttn-I domains, Zr-in-titanite thermometry yields high temperatures of 773 to 851 °C at 2.5 GPa, and petrographic observations reveal the presence of melt pseudomorphs. Thus, they are interpreted to have grown from hydrous melts in the early exhumation stage. In contrast, the Ttn-II domains were texturally equilibrated with amphibolite-facies minerals such as biotite and plagioclase and contain inclusions of plagioclase and quartz. The Zr-in-titanite thermometry yields lower temperatures of 627 to 685 °C at 1.0 GPa. In combination with their REE patterns, they are interpreted to have grown from aqueous solutions at amphibolite-facies metamorphic conditions during further exhumation. The differences in Th and Sr contents are prominent between the Ttn-I and Ttn-II domains, signifying the compositional difference between the hydrous melts and aqueous solutions. Therefore, the polygenetic titanite in the UHP metamorphic rocks provides insights into the geochemical property of metamorphic fluids during the continental subduction-zone processes. This article is protected by copyright. All rights reserved.

Description: Voltage controlled 180° magnetization reversal has been achieved in BiFeO3-based multiferroic heterostructures, which is promising for the future development of low-power spintronic devices. However, all existing reports involve the use of an in-plane voltage that is unfavorable for practical device applications. Here, we investigate, using phase-field simulations, the out-of-plane (i.e., perpendicular to heterostructures) voltage controlled magnetism in heterostructures consisting of CoFe nanodots and (110) BiFeO3 thin film or island. It is predicted that the in-plane component of the canted magnetic moment at the CoFe/BiFeO3 interface can be reversed repeatedly by applying a perpendicular voltage across the bottom (110) BiFeO3 thin film, which further leads to an in-plane magnetization reversal in the overlaying CoFe nanodot. The non-volatility of such perpendicular voltage controlled magnetization reversal can be achieved by etching the continuous BiFeO3 film into isolated nanoislands with the same in-plane sizes as the CoFe nanodot. The findings would provide general guidelines for future experimental and engineering efforts on developing the electric-field controlled spintronic devices with BiFeO3-based multiferroic heterostructures. Scientific Reports 5 doi: 10.1038/srep10459

Description: We investigated the variability in the North African dust transport routes over the Atlantic (NAD routes) by extracting the dust transport central axis using Moderate Resolution Imaging Spectroradiometer (MODIS) aerosol data for 2001–2015. The results showed that the NAD routes can be classified into two regimes, a southern-route centered at the southernmost position of 6.08 ± 1.12°N during November to March and a northern-route centered at the northernmost position of 18.21 ± 1.04°N during April to October. In the southern-route, large inter-variation was correlated with the Intertropical Convergence Zone (ITCZ) and North Atlantic Oscillation (NAO), but the ITCZ and NAO jointly explained only 38% of the variation. In the northern-route, the ITCZ alone explained 67% of the inter-variation. The extracted trends during 2001–2015 exhibited a northward shift of 1.68° for the southern-route and of 0.52° for the northern-route. The causes for the shift were also examined.

Description: Composite multiphase solid (MS) inclusions composed of carbonate and silicate minerals have been found for the first time in metamorphic garnet from ultrahigh-pressure (UHP) eclogite from the Dabie orogen. These inclusions are morphologically euhedral to subhedral, and some show relatively regular shapes approaching the negative crystal shape of the host garnet. Radial fractures often occur in garnet hosting the inclusions. The inclusions are primarily composed of variable proportions of carbonate and silicate minerals such as calcite, quartz, K-feldspar and plagioclase, with occasional occurrences of magnetite, zircon and barite. They are categorized into two groups based on the proportions of carbonate and silicate phases. Group I is carbonate-dominated with variable proportions of silicate minerals, whereas Group II is silicate-dominated with small proportions of carbonates. Trace element analysis by LA-ICPMS for the two groups of MS inclusions yields remarkable differences. Group I inclusions exhibit remarkably lower REE contents than Group II inclusions, with significant LREE enrichment and large fractionation between LREE and HREE in the chondrite-normalized REE diagram. In contrast, Group II inclusions show rather flat REE patterns with insignificant fractionation between LREE and HREE. In the primitive mantle-normalized spidergram, Group I inclusions exhibit positive anomalies of Zr and Hf, whereas Group II inclusions show negative anomalies of Zr and Hf. Nevertheless, both groups exhibit positive anomalies of Ba, U, Pb and Sr, but negative anomalies of Nb and Ta, resembling the composition of common continental crust. Group I inclusions have higher Ba and U contents than Group II inclusions. Combined with petrological observations, the two groups of MS inclusions are interpreted as having crystallized from composite silicate and carbonate melts during continental subduction-zone metamorphism. The differences in trace element composition between the two groups are primarily attributed to the proportions of carbonate and silicate phases in the MS inclusions. The silicate melts were derived from the breakdown of hydrous minerals such as paragonite and phengite, whereas the occurrence of carbonate melts indicates involvement of carbonate minerals in the partial melting and thus has great bearing on recycling of supracrustal carbon into the mantle. The coexistence of silicate and carbonate melts in the eclogitic garnet provides insights into the nature of hydrous melts in the subduction factory This article is protected by copyright. All rights reserved.

Description: TLR4-mediated inflammation promotes foam cell formation of vascular smooth muscle cell by upregulating ACAT1 expression Cell Death and Disease 5, e1574 (December 2014). doi:10.1038/cddis.2014.535 Authors: Y-W Yin, S-Q Liao, M-J Zhang, Y Liu, B-H Li, Y Zhou, L Chen, C-Y Gao, J-C Li & L-L Zhang

Description: 〈sec〉〈st〉Synopsis〈/st〉〈p〉〈textbox textbox-type="graphic"〉〈p〉〈inline-fig〉〈/inline-fig〉〈/p〉〈/textbox〉〈/p〉 〈p〉OST1 kinase, the master freezing tolerance regulator in 〈i〉Arabidopsis〈/i〉, is inhibited at warm temperatures by interaction with the membrane-localized phosphatase EGR2. This interaction depends on EGR2 N-myristoylation, attenuation of which upon cold stress provides a mean of activating OST1 at low temperatures.〈/p〉 〈p〉 〈l type="unord"〉〈li〉〈p〉Plant type 2C protein phosphatase EGR2 is myristoylated by N-myristoyltransferase NMT1.〈/p〉〈/li〉 〈li〉〈p〉EGR2 interacts with and inhibits OST1 kinase activity.〈/p〉〈/li〉 〈li〉〈p〉NMT1-mediated myristoylation of EGR2 is important for its interaction with OST1.〈/p〉〈/li〉 〈li〉〈p〉Cold stress attenuates EGR2 myristoylation and decreases its interaction with OST1, thereby activating OST1.〈/p〉〈/li〉〈/l〉 〈/p〉〈/sec〉

Description: 〈p〉OST1 (open stomata 1) protein kinase plays a central role in regulating freezing tolerance in 〈i〉Arabidopsis〈/i〉; however, the mechanism underlying cold activation of OST1 remains unknown. Here, we report that a plasma membrane-localized clade-E growth-regulating 2 (EGR2) phosphatase interacts with OST1 and inhibits OST1 activity under normal conditions. EGR2 is N-myristoylated by N-myristoyltransferase NMT1 at 22°C, which is important for its interaction with OST1. Moreover, myristoylation of EGR2 is required for its function in plant freezing tolerance. Under cold stress, the interaction of EGR2 and NMT1 is attenuated, leading to the suppression of EGR2 myristoylation in plants. Plant newly synthesized unmyristoylated EGR2 has decreased binding ability to OST1 and also interferes with the EGR2-OST1 interaction under cold stress. Consequently, the EGR2-mediated inhibition of OST1 activity is released. Consistently, mutations of 〈i〉EGRs〈/i〉 cause plant tolerance to freezing, whereas overexpression of 〈i〉EGR2〈/i〉 exhibits decreased freezing tolerance. This study thus unravels a molecular mechanism underlying cold activation of OST1 by membrane-localized EGR2 and suggests that a myristoyl switch on EGR2 helps plants to adapt to cold stress.〈/p〉

Description: IRAK1 mediates TLR4-induced ABCA1 downregulation and lipid accumulation in VSMCs Cell Death and Disease 6, e1949 (October 2015). doi:10.1038/cddis.2015.212 Authors: L Guo, C-H Chen, L-L Zhang, X-J Cao, Q-L Ma, P Deng, G Zhu, C-Y Gao, B-H Li, Y Pi, Y Liu, Z-C Hu, L Zhang, Z-P Yu, Z Zhou & J-C Li

Description: Involvement of miR-9/MCPIP1 axis in PDGF-BB-mediated neurogenesis in neuronal progenitor cells Cell Death and Disease 4, e960 (December 2013). doi:10.1038/cddis.2013.486 Authors: L Yang, J Chao, Y H Kook, Y Gao, H Yao & S J Buch

Description: TRPV1 activation impedes foam cell formation by inducing autophagy in oxLDL-treated vascular smooth muscle cells Cell Death and Disease 5, e1182 (April 2014). doi:10.1038/cddis.2014.146 Authors: B-H Li, Y-W Yin, Y Liu, Y Pi, L Guo, X-J Cao, C-Y Gao, L-L Zhang & J-C Li