ALBERT

Description: Neoalbaconol induces energy depletion and multiple cell death in cancer cells by targeting PDK1-PI3-K/Akt signaling pathway Cell Death and Disease 4, e804 (September 2013). doi:10.1038/cddis.2013.324 Authors: Q Deng, X Yu, L Xiao, Z Hu, X Luo, Y Tao, L Yang, X Liu, H Chen, Z Ding, T Feng, Y Tang, X Weng, J Gao, W Yi, A M Bode, Z Dong, J Liu & Y Cao

Description: The Xincheng gold deposit, hosted by the Early Cretaceous 132 to 123 Ma Guojialing-type granitoids in northwest Jiaodong Peninsula, southeast North China craton, formed about 2 billion years later than regional metamorphism of the Archean Jiaodong basement rocks. The Xincheng deposit comprises mineralized zones with three types of hydrothermal pyrite associated with gold, tellurides, and a variety of sulfides: py 1 as disseminated euhedral to subhedral grains in altered granitoids around quartz veins; py 2 as subhedral grains with brittle cataclastic textures and fractures in quartz-pyrite veins; and py 3 as subhedral, partially corroded crystals in sulfide-rich veins or veinlets. All three generations of pyrite are unzoned and have low trace element contents, including very low lattice-bound gold contents: (py 1 : 0.180 ppm; py 2 : 0.053 ppm; py 3 : 0.060 ppm). Given that there is 10 to 15% pyrite in the ore zone at Xincheng, its very low gold content indicates that it contributes 〈0.2% of gold to the 7.75 g/t gold in the orebody. Instead, over 99% of the gold is present as discrete electrum and/or gold (total range 0.02–59% silver) grains, which are largely sited in fractures at all scales in pyrite, other ore minerals, and quartz. Importantly, visible gold in py 3 is also sited on solution-corroded pyrite grains. The pyrite textural and geochemical data indicate that it is impossible to derive the high gold-grade orebodies through local remobilization of originally lattice-bound gold in pyrite. Instead, the gold is interpreted to have been deposited through sulfidation reactions and phase separation of a H 2 O-CO 2 ore fluid during progressive brittle cataclastic deformation associated with seismic activity and regional sinistral transtensional shear movement. This concomitant fluid infiltration and deformation caused episodic deposition and fracturing and corrosion of earlier formed pyrite and deposited visible gold in dilational cracks. The coupled development of the transtensional, rather than normal transpressional setting, and precipitation of gold within dilational veins and wall-rock alteration facilitated the deposition of visible gold and an exceptionally high gold tenor. All deposit characteristics indicate that the Xincheng gold deposit is a member of the epizonal orogenic deposit class.

Description: 〈p〉Targeting immune checkpoints, such as PD-L1 and its receptor PD-1, has opened a new avenue for treating cancers. Understanding the regulatory mechanism of PD-L1 and PD-1 will improve the clinical response rate and efficacy of PD-1/PD-L1 blockade in cancer patients and the development of combinatorial strategies. VGLL4 inhibits YAP-induced cell proliferation and tumorigenesis through competition with YAP for binding to TEADs. However, whether VGLL4 has a role in anti-tumor immunity is largely unknown. Here, we found that disruption of Vgll4 results in potent T cell-mediated tumor regression in murine syngeneic models. VGLL4 deficiency reduces PD-L1 expression in tumor cells. VGLL4 interacts with IRF2BP2 and promotes its protein stability through inhibiting proteasome-mediated protein degradation. Loss of IRF2BP2 results in persistent binding of IRF2, a transcriptional repressor, to PD-L1 promoter. In addition, YAP inhibits IFN-inducible PD-L1 expression partially through suppressing the expression of VGLL4 and IRF1 by YAP target gene miR-130a. Our study identifies VGLL4 as an important regulator of PD-L1 expression and highlights a central role of VGLL4 and YAP in the regulation of tumor immunity.〈/p〉

Description: We present structural field observations, in situ zircon U-Pb ages, Hf isotopic compositions, geochemistry, and Sr-Nd isotope data from the Puziba granitoid intrusions in the Qinling orogenic belt (China). These intrusions occur as ENE-WSW–oriented dike swarms in a highly deformed phyllite-matrix mélange along several major fault zones within the Mianlue suture zone. Granitoid rocks have a relatively wide range of SiO 2 (69–77 wt%, volatile-free) and total alkali contents (Na 2 O + K 2 O = 2.76–4.83 wt%), and K 2 O/Na 2 O ratios 〉1, and they mostly fall in the granite-granodiorite fields in the total alkalis versus silica diagram. They display relative enrichments of light rare earth elements (LREEs) and relatively flat heavy rare earth elements patterns (HREEs) with weak negative Eu anomalies (Eu = 0.56–0.95) on chondrite-normalized rare earth element (REE) diagrams. They show enrichment in Th and Zr and depletion in high field strength elements (HFSEs; e.g., Nb, P, and Ti). They are enriched in large ion lithophile elements (LILE) and LREEs and have low zircon Hf ( t ) (–2.8 to 4.2) values, relatively high initial 87 Sr/ 86 Sr ratios (0.7107–0.7188), and variable Mg# (22–46). Their U-Pb zircon crystallization age is ca. 215 Ma, but they also show inherited zircon age clusters in the Paleoproterozoic, Mesoproterozoic, Neoproterozoic, and Paleozoic, with two prominent peaks at ca. 753 Ma and ca. 805 Ma. The high Rb and Ta elemental abundances, smooth chondrite-normalized REE patterns, and Nd ( t ) values (–5 to –3) of the Puziba dike rocks characterize them as K-rich, calc-alkaline granites. Their magmas were derived from partial melting of garnet-amphibole–bearing lower crust that was triggered by slab breakoff–induced asthenospheric upwelling in the aftermath of the oblique collision of the North and South China blocks during the Late Triassic. Emplacement of the ENE-WSW–oriented Puziba dike swarms was associated with a transtensional stress regime along/across the collisional Mianlue suture zone.

Description: In multiferroic hexagonal manganites (RMnO 3 , R = Y, Sc, Ho-Lu), positions of Mn ions can affect both their in-plane and inter-plane exchange interactions, thus they are of utmost importance for the magneto-elastic coupling of rare-earth compounds. However, the reported in-plane positions of Mn ions by different groups are controversial and there is a lack of convenient method to identify the shift of Mn ions from the center of MnO 5 bipyramids. Here, we demonstrate that the transmission electron microscopy is an efficient technique to characterize the positions of Mn ions and the shift of Mn ions can be directly recognized from the selected area electron diffraction (SAED) patterns. Through systematic studies on the SAED patterns acquired from regions with stoichiometric and non-stoichiometric ratio, we conclude that the intensities of ( 1 1 ¯ 0 ) and ( 2 2 ¯ 0 ) diffraction spots are very sensitive to the in-plane positions of Mn ions. We ascribe the off-centered shift of Mn ions to the in-plane oxygen vacancies and this is verified by combined electron microscopy and electron diffraction pattern calculations. Our results indicate that SAED can be used to judge both local positions of Mn ions and local oxygen deficiency in RMnO 3 systems.

Description: The mechanical properties of a super-lattice architecture composed of nanocrystalline Mg and Mg-Al amorphous alloy are investigated using molecular dynamics simulation. The results indicate that deformation mechanism of nanocrystalline Mg is obviously affected by the amorphous boundary spacing and temperature. The strength of the material increases with the decrease of amorphous boundary spacing, presenting a Hall-Petch effect at both 10 K and 300 K. A stress platform and following stiffness softening, as well as a linear strengthening in the plastic stage, are observed when the amorphous boundary spacing below 8.792 nm at 10 K. The implying reason may be that the amorphous boundary acts as the dislocations emission and absorption source. However, the second stress peak is not observed for the models at 300 K. Instead, the flow stress in plastic stage is a nearly constant value. The simulation demonstrates the emergence of the new grain, accompanied by the deformation twins and stacking faults associated with the plastic behaviors at 300 K. The general conclusions derived from this work may provide a guideline for the design of high-performance hexagonal close-packed metals.

Description: Ocean acidification (OA), caused by seawater CO 2 uptake, has significant impacts on marine calcifying organisms and phototrophs. However, the response of bacterial communities, who play a crucial role in marine biogeochemical cycling, to OA is still not well understood. Previous studies have shown that the diversity and structure of microbial communities change undeterminably with elevated p CO 2 . Here, novel phylogenetic molecular ecological networks (pMENs) were employed to investigate the interactions of native bacterial communities in response to OA in the Arctic Ocean through a mesocosm experiment. The pMENs results were in line with the null hypothesis that elevated p CO 2 /pH does not affect biogeochemistry processes. The number of nodes within the pMENs and the connectivity of the bacterial communities were similar, despite increased p CO 2 concentrations. Our results indicate that elevated p CO 2 did not significantly affect microbial community structure and succession in the Arctic Ocean, suggesting bacterioplankton community resilience to elevated p CO 2 . The competitive interactions among the native bacterioplankton, as well as the modular community structure, may contribute to this resilience. This pMENs-based investigation of the interactions among microbial community members at different p CO 2 concentrations provides a new insight into our understanding of how OA affects the microbial community.