ALBERT

Description: Steady-state pyroxene dissolution rates in aqueous solutions have been measured at temperatures from 25 to 374 °C at a pressure of 23 MPa and at neutral pH. The pyroxene is hedenbergitic clinopyroxene, of composition Na 0.04 Ca 0.95 Mg 0.3 Fe 2+ 0.64 Fe 3+ 0.06 Al 0.04 Si 1.97 O 6 . All experiments were performed at conditions far from equilibrium in Ti-alloy mixed-flow reactors. In most runs, the reactive solutions were undersaturated with respect to pyroxene and secondary minerals were rarely found at the reacted surface. The dissolution is non-stoichiometric in most cases, while the different chemical elements of the pyroxene are released at different rates. Stoichiometric steady-state dissolution was obtained in neutral solution at 100 °C. The release rates of the different elements vary with temperature and solution chemistry. The dissolution rates (r Si ) in neutral pH conditions increase with temperature from 25 to 300 °C, reach a maximum at 300 °C, and then decrease with continued temperature increase. At a given temperature, the rates decrease significantly with increasing pH of the reactive fluid and are also affected by the activities of Ca, Mg, Fe in the solution. At neutral pH, the dependence of the pyroxene dissolution rates on activities of Ca, Mg, Fe and H + in the fluid can be expressed by the relation: \[ \hbox{ log\hspace{0.17em} }{r}_{+}(T,{a}_{i})=\hbox{ log\hspace{0.17em} }(A-{E}_{a}/(2.303\hspace{0.17em}RT)+\alpha \hspace{0.17em}\hbox{ log\hspace{0.17em} }{({a}_{{\hbox{ H }}^{+}})}^{Zi}/{a}_{{{\hbox{ M }}_{i}}^{Zi+}}) \] where r + is the far-from-equilibrium dissolution rate, R the gas constant, T the absolute temperature, Z i valence of metal M i and a i represents the activity of the subscript aqueous species. E a equals 22.667 kJ/mole/K and A = 2.011 x 10 –7 mole/cm 2 /s; α is the empirical reaction rate order, which can be derived from the experimental results. At temperatures below 300 °C, the exchange reactions 2H + M i 2+ , where M i 2+ refers to divalent cations Mg 2+ , Fe 2+ or Ca 2+ , dominate in the dissolution. The following evolution of the dissolution with temperature is proposed: at 300 °C, the tetrahedral Si–O bonds break after the M i 2+ –O bonds in adjacent octahedral positions have been removed by proton exchange reaction, whereas, above 300 °C, the breaking of the octahedral M i 2+ –O bonds occurs after adjacent tetrahedral Si–O bonds have been broken.

Description: The effect of a medium-density DC-current and its direction on the directional solidification microstructure and cooling behavior of Pb-80wt%Sn alloy were studied. Experimental results indicated that the microstructure was refined with DC compared to the one without. With the increase of DC density, the primary ( λ 1 ) and secondary ( λ 2 ) dendrite arm spacing of the primary phase decrease clearly. It is also found that not only the intensity of the DC current but also its direction affects the microstructure. The size of λ 1 and λ 2 , in samples treated with positive DC, decreases more clearly than in those with negative DC. The interface morphology in samples processed without and with DC is different when the current direction is changed. Finally, the mechanism of microstructure evolution is discussed.

Description: A new indirect mineral carbonation process is studied which could mitigate anthropogenic CO 2 emissions. In this process, magnesium silicate is dissolved in HCl and the resulting MgCl 2 solution is subsequently reacted with CO 2 in NH 3 . HCl and NH 3 are recovered from NH 4 Cl in a two-step thermal decomposition. Carbonation is investigated from 30 °C to 180 °C at 4 MPa CO 2 pressure and Mg-carbonate morphology transformations with increasing temperature are identified. Nesquehonite (MgCO 3  · 3H 2 O) is obtained below 70 °C, hydromagnesite (Mg 5 (CO 3 ) 4 (OH) 2  · 4H 2 O) is formed at 100 °C, and further temperature increase to 180 °C leads to magnesite (MgCO 3 ) precipitation. Nesquehonite and magnesite can fix more CO 2 per mole Mg than hydromagnesite. In order to mitigate anthropogenic CO 2 emissions, a new indirect mineral carbonation process was developed. Magnesium silicate was dissolved in HCl and the resulting MgCl 2 solution was subsequently reacted with CO 2 in NH 3 . HCl and NH 3 were recovered from NH 4 Cl in a two-step thermal decomposition. Compared with hydromagnesite, nesquehonite and magnesite can fix more CO 2 per mole magnesium.

Description: The field of perceptual learning has identified changes in perceptual templates as a powerful mechanism mediating the learning of statistical regularities in our environment. By measuring threshold-vs.-contrast curves using an orientation identification task under varying levels of external noise, the perceptual template model (PTM) allows one to disentangle various sources...

Description: Seasonal antigenic drift of circulating influenza virus leads to a requirement for frequent changes in vaccine composition, because exposure or vaccination elicits human antibodies with limited cross-neutralization of drifted strains. We describe a human monoclonal antibody, CH65, obtained by isolating rearranged heavy- and light-chain genes from sorted single plasma cells, coming from a subject immunized with the 2007 trivalent influenza vaccine. The crystal structure of a complex of the hemagglutinin (HA) from H1N1 strain A/Solomon Islands/3/2006 with the Fab of CH65 shows that the tip of the CH65 heavy-chain complementarity determining region 3 (CDR3) inserts into the receptor binding pocket on HA1, mimicking in many respects the interaction of the physiological receptor, sialic acid. CH65 neutralizes infectivity of 30 out of 36 H1N1 strains tested. The resistant strains have a single-residue insertion near the rim of the sialic-acid pocket. We conclude that broad neutralization of influenza virus can be achieved by antibodies with contacts that mimic those of the receptor.

Description: Silencing of Jagged1 inhibits cell growth and invasion in colorectal cancer Cell Death and Disease 5, e1170 (April 2014). doi:10.1038/cddis.2014.137 Authors: Y Dai, G Wilson, B Huang, M Peng, G Teng, D Zhang, R Zhang, M P A Ebert, J Chen, B C Y Wong, K W Chan, J George & L Qiao

Description: TRAF1 is a key mediator for hepatic ischemia/reperfusion injury Cell Death and Disease 5, e1467 (October 2014). doi:10.1038/cddis.2014.411 Authors: X-F Zhang, R Zhang, L Huang, P-X Wang, Y Zhang, D-S Jiang, L-H Zhu, S Tian, X-D Zhang & H Li

Description: 〈p〉The uncontrollable growth of lithium (Li) dendrites seriously impedes practical applications of Li metal batteries. Various lithiophilic conductive frameworks, especially carbon hosts, are used to guide uniform Li nucleation and thus deliver a dendrite-free composite anode. However, the lithiophilic nature of these carbon hosts is poorly understood. Herein, the lithiophilicity chemistry of heteroatom-doped carbon is investigated through both first principles calculations and experimental verifications to guide uniform Li nucleation. The electronegativity, local dipole, and charge transfer are proposed to reveal the lithiophilicity of doping sites. Li bond chemistry further deepens the understanding of lithiophilicity. The O-doped and O/B–co-doped carbons exhibit the best lithiophilicity among single-doped and co-doped carbons, respectively. The excellent lithiophilicity achieved by O-doping carbon is further validated by Li nucleation overpotential measurement. This work uncovers the lithiophilicity chemistry of heteroatom-doped carbons and affords a mechanistic guidance to Li metal anode frameworks for safe rechargeable batteries.〈/p〉

Description: Although the rhesus macaque is a unique model for the translational study of human diseases, currently its use in biomedical research is still in its infant stage due to error-prone gene structures and limited annotations. Here, we present RhesusBase for the monkey research community ( http://www.rhesusbase.org ). We performed strand-specific RNA-Seq studies in 10 macaque tissues and generated 1.2 billion 90-bp paired-end reads, covering 〉97.4% of the putative exon in macaque transcripts annotated by Ensembl. We found that at least 28.7% of the macaque transcripts were previously mis-annotated, mainly due to incorrect exon–intron boundaries, incomplete untranslated regions (UTRs) and missed exons. Compared with the previous gene models, the revised transcripts show clearer sequence motifs near splicing junctions and the end of UTRs, as well as cleaner patterns of exon–intron distribution for expression tags and cross-species conservation scores. Strikingly, 1292 exon–intron boundary revisions between coding exons corrected the previously mis-annotated open reading frames. The revised gene models were experimentally verified in randomly selected cases. We further integrated functional genomics annotations from 〉60 categories of public and in-house resources and developed an online accessible database. User-friendly interfaces were developed to update, retrieve, visualize and download the RhesusBase meta-data, providing a ‘one-stop’ resource for the monkey research community.

Description: Abstract A century ago the pioneering book published in 1924 “Die Klimate der geologischen Vorzeit “explained by plate motion the evolution of vegetation revealed in sedimentary records. Nevertheless, they did not invoke climate changes.. In the second part of the 20th century the intricate relationship between tectonics, long‐term carbon cycle and climate was depicted by James G. C. Walker (1981). Since these major steps, climate modeling of the Earth system kept on improving and including more and more components and processes to enable the investigation deep time periods using general circulation model that can account for atmosphere and ocean dynamics. Here we illustrate long but drastic climate changes clearly related with tectonics, through three different examples: The crucial role of paleogeography (continental distribution) to explain the drawdown of atmospheric carbon dioxide and the huge glaciation associated that occurred during the Neoproterozoic period. The shrinkage of large epicontinental Paratethys that covered a large part of Eastern Europe and Western Asia and its impact on both monsoonal systems (African and Asian) since 40 Ma. The large impact of mountain range uplifts since Eocene both in Asia (Tibetan Plateau and Himalaya) and in Africa (buildup of the rift), on atmosphere and ocean dynamics. These studies not only allow for testing the ability of Earth system models to capture long term changes of Earth climate, but they pinpoint the pivotal role tectonics played in shaping the long‐term evolution of atmospheric CO2 and monsoon patterns.