Genetic structure and demographic history of Cycas chenii(Cycadaceae),an endangered species with extremely small populations

Geological activities and climate oscillations during the Quaternary period profoundly impacted the distribution of species in Southwest China. Some plant species may be harbored in refugia, such as the dry-hot valleys of Southwest China. Cycas chenii X. Gong & W. Zhou, a critically endangered cycad species, which grows under the canopy in subtropical evergreen broad-leaved forests along the upstream drainage area of the Red River, is endemic to this refugium. In this study, 60 individuals of C. chenii collected from six populations were analyzed by sequencing two chloroplast intergenic spacers(cp DNA:psb A-trn H and trn L-trn F) and two nuclear genes(PHYP and RBP-1). Results showed high genetic diversity at the species level, but low within-population genetic diversity and high interpopulation genetic differentiation. A Bayesian phylogenetic tree based on cp DNA showed that five chloroplast haplotypes were clustered into two clades, which corresponds to the division of the western and eastern bank of the Red River. These data indicate a possible role for the Red River as a geographic barrier to gene flow in C. chenii.Based on our findings, we propose appropriate in situ and ex situ conservation strategies for C. chenii.

Fabrication and application of hierarchical mesoporous MoO2/Mo2C/C microspheres

Hierarchical mesoporous MoO2/Mo2C/C microspheres,which are composed of primary nanoparticles with a size of about 30 nm,have been designed and synthesized through polymer regulation and subsequent carbonization processes.The as-synthesized microspheres were characterized by XRD,Raman,SEM,TEM,XPS measurements and so on.It was found that polyethylene glycol acted as a structure-directing agent,mild reducing agent and carbon source in the formation of these hierarchical mesoporous Mo O2/Mo2C/C microspheres.Moreover,the electrochemical property of the microspheres was also investigated in this work.Evaluated as an anode material for lithium ion batteries,the hierarchical mesoporous Mo O2/Mo2C/C electrode delivered the discharge specific capacities of 665 and 588 m Ah/g after 100 cycles at current densities of 100 and 200 m A/g,respectively.The satisfactory cycling performance and controllable process facilitate the practical applications of the hierarchical mesoporous Mo O2/Mo2C/C as a potential anode material in high-energy density lithium-ion batteries.

The effect of different layered materials on the tribological properties of PTFE composites

Two-dimensional(2D)lamellar materials have unique molecular structures and mechanical properties,among which molybdenum disulfide(MoS2)and graphitic carbon nitride(g-C3N4)with different interaction forces served as reinforcing phase for polytetrafluoroethylene(PTFE)composites in the present study.Thermal stability,tribological and thermomechanical properties of composites were comprehensively investigated.It was demonstrated that g-C3N4 improved elastic deformation resistance and thermal degradation characteristics.The addition of g-C3N4 significantly enhanced anti-wear performance under different loads and speeds.The results indicated that PTFE composites reinforced by g-C3N4 were provided with better properties because the bonding strength of g-C3N4 derived from hydrogen bonds(H-bonds)was stronger than that of MoS2 with van der Waals force.Consequently,g-C3N4 exhibited better thermomechanical and tribological properties.The result of this work is expected to provide a new kind of functional filler for enhancing the tribological properties of polymer composites.

A reciprocal inhibitory relationship between adiponectin and mammalian cytosolic thioredoxin

当 adiponectin 是 adipokine 时， Thioredoxin 是氧化还原作用蛋白质。他们的关系是欣赏的更少。这里，我们与长期的妨碍的肺的疾病的尖锐恶化在病人的浆液显示出那， thioredoxin 的减少的活动作为动脉的氧减少的部分压力与 adiponectin 的增加的水平共存。从有 adiponectin 大美人鼠标并且在 vitro 实验的结果，我们发现了一种相互的禁止的关系， adiponectin 由禁止 cytosolic thioredoxin (Trx1 ) 表示，而浆液 Trx1 影响 adiponectin multimerization。在细胞外的 Trx1 和 adiponectin 之间的协会稀释他们的功能。这种关系是动态的，并且相关与一身体生理的条件。

Ultrasmall AU10 clusters anchored on pyramid-capped rectangular TiO2 for olefin oxidation

UltrasmaU Au10 clusters have a unique electronic structure and can act as a charge reservoir to donate electrons or accept charges. This is particularly important for catalysis, since it leads to facile charge transfer across the interface between the gold species and the oxide substrate. To determine the electronic and structural effects of Au10 on the catalytic oxidation, a TiO2 charge carrier was chosen as the substrate to anchor Au10 for olefin oxidation. Au10 supported on TiO2-RP （RP = pyramid-capped columnar structure） exhibited superior catalytic activity to Au10/TiO2 nanotubes and Au10/P25. In addition, the supported Au10 clusters gave rise to higher activity than supported Au20, Au144 clusters, and 5 nm Au nanocrystals. The superior catalytic ability of Au^0fFiO2-RP arises from the charge/discharge effect of the Au10/TiO2-RP interface, which effectively improves the formation of active oxygen species on electron-rich gold atoms at the terminal position of Au10, and promotes the activation of olefin C--C bonds on the electron-deficient gold atoms of Au10.

GCN2 deficiency protects mice from denervation-induced skeletal muscle atrophy via inhibiting FoxO3a nuclear translocation

Dear Editor Several recent clinical studies have indicated that dietary supplementation with branched-chain amino acids （BCAA）, particularly with leucine, is an effective anti-atrophic therapy （Bauer et al., 2015; Tsien et al., 2015; English et al., 2016）. In animal models, BCAA can prevent denervation （Ribeiro et al., 2015）, hindlimb suspension （Maki et al., 2012; Jang et al., 2015） or dexamethasone-induced （Yamamoto et al., 2010） muscle atrophy. General control nonderepressible 2 kinase （GCN2） is a well-known amino-acid sensor. Under conditions of amino-acid deprivation, the increased level of uncharged transfer RNA （tRNA） activates GCN2 through binding to the histadyl-tRNA synthetase-like domain （Wek et al., 1995）. Upon activation, GCN2 phosphorylates eukaryotic initiation factor 2 alpha at Ser51, which leads to translational arrest and restoration of amino acid home- ostasis （Wek et al., 1995; Sood et al., 2000）. As amino acids are potent modulators of protein turnover in skeletal muscle, we proposed that GCN2 may affect denervation-induced muscle atrol0hv, but the detail mechanism remains unclear.

hTAC internalizes via both clathrin-dependent and clathrin-independent endocytosis in mammalian cells

Dear Editor, Endocytosis is a crucial process employed by cells to internal- ize nutrients and turnover membrane components and is essential for many functions, including nutrient uptake, signal transduction, cytokinesis, morphogenesis, cell adhesion and migration. Endocytosis is classified as clathrin-dependent endocytosis （CDE） or clathrin-independent endocytosis （CIE） according to its dependence on clathrin. Several different CIE pathways have been proposed, including caveolin-dependent endocytosis, flotillin-dependent endocytosis, the clathrin-inde- pendent carrier pathway, ARF6-dependent endocytosis, phagocytosis, macropinocytosis, the IL2RI3 pathway （Doherty and McMahon, 2009）, the newly identified fast endophilin-me- diated endocytosis pathway （Boucrot et al., 2015） and the EGFR-NCE pathway （Caldieri et al., 2017）.

Polymer/Metal Segmental Janus Nanoparticles

Polymer/metal composite segmental Janus nanoparticles （NPs） are synthesized by sequential growth against poly（4-vinylpyridine） （P4VP） crosslinked cP4VP-PS Janus NPs. A Janus cluster of poly（4-vinylpyridine）-block-polystyrene （P4VP-b-PS） diblock copolymer is self-organized after absorption onto a silica patchy sphere via hydrogen bonding. Selective crosslinking of P4VP leads to the formation of robust cP4VP-PS Janus NPs. Within the cP4VP domain, functional species such as metals are preferentially grown by in situ reduction. Other thiol-capped polymers, for example, thiol-capped poly（N-isopropylacrylamide） （PNIPAM-SH）, can be conjugated onto the opposite side to form polymer/metal triple segmental Janus NPs. The hyperthermia effect ofAu NP of PNIPAM-Au@cP4VP-PS by near infrared （NIR） irradiation can trigger a fast transition from amphiphilic to hydrophobic of the Janus NPs at low surrounding temperature. De-stabilization of the emulsion is NIR triggered although the system temperature is below LCST （-32 ℃）.