Selective and efficient catalytic conversion of carbon dioxide (CO 2 ) into value-added fuels and feedstocks provides an ideal avenue to high-density renewable energy storage. An impediment to enabling deep CO 2 reduction to oxygenates and hydrocarbons (e.g., C 2+ compounds) is the difficulty of coupling carbon−carbon bonds efficiently. Copper in the +1 oxidation state has been thought to be active for catalyzing C 2+ formation, whereas it is prone to being reduced to Cu 0 at cathodic potentials. Here we report that catalysts with nanocavities can confine carbon intermediates formed in situ, which in turn covers the local catalyst surface and thereby stabilizes Cu + species. Experimental measurements on multihollow cuprous oxide catalyst exhibit a C 2+ Faradaic efficiency of 75.2 ± 2.7% at a C 2+ partial current density of 267 ± 13 mA cm −2 and a large C 2+ -to-C 1 ratio of ∼7.2. Operando Raman spectra, in conjunction with X-ray absorption studies, confirm that Cu + species in the as-designed catalyst are well retained during CO 2 reduction, which leads to the marked C 2+ selectivity at a large conversion rate.

The recent discovery that GRP78/BiP, a typical endoplasmic reticulum (ER) lumenal chaperone, can be expressed on the cell surface, interacting with an increasing repertoire of surface proteins and acting as receptor in signaling pathways, represents a paradigm shift in its biological function. However, the mechanism of GRP78 trafficking from the ER to the cell surface is not well understood. Using a combination of cellular, biochemical, and mutational approaches, we tested multiple hypotheses. Here we report that ER stress actively promotes GRP78 localization on the cell surface, whereas ectopic expression of GRP78 is also able to cause cell surface relocation in the absence of ER stress. Moreover, deletion of the C-terminal ER retention motif in GRP78 alters its cell surface presentation in a dose-dependent manner; however, mutation of the putative O-linked glycosylation site Thr 648 of human GRP78 is without effect. We also identified the exposure of multiple domains of GRP78 on the cell surface and determined that binding of extracellular GRP78 to the cell surface is unlikely. A new topology model for cell surface GRP78 is presented.

The receptor tyrosine kinase EphB2 is expressed by colon progenitor cells; however, only 39% of colorectal tumors express EphB2 and expression levels decline with disease progression. Conversely, EphB4 is absent in normal colon but is expressed in all 102 colorectal cancer specimens analyzed, and its expression level correlates with higher tumor stage and grade. Both EphB4 and EphB2 are regulated by the Wnt pathway, the activation of which is critically required for the progression of colorectal cancer. Differential usage of transcriptional coactivator cyclic AMP-responsive element binding protein-binding protein (CBP) over p300 by the Wnt/Bcatenin pathway is known to suppress differentiation and increase proliferation. We show that the B-catenin-CBP complex induces EphB4 and represses EphB2, in contrast to the B-catenin-p300 complex. Gain of EphB4 provides survival advantage to tumor cells and resistance to innate tumor necrosis factor-related apoptosis-inducing ligand-mediated cell death. Knockdown of EphB4 inhibits tumor growth and metastases. Our work is the first to show that EphB4 is preferentially induced in colorectal cancer, in contrast to EphB2, whereby tumor cells acquire a survival advantage.

A spiro diacetal structure based on renewable resources was utilized to synthesize thermosets combining ready recyclability and high performance.