Quantitative determination of interlayer electronic coupling at various critical points in bilayer Mo S 2

Tailoring interlayer coupling has emerged as a powerful tool to tune the electronic structure of van der Waals (vdW) bilayers. One example is the usage of the “moiré pattern” to create controllable two-dimensional electronic superlattices through the configurational dependence of interlayer electronic couplings. This approach has led to some remarkable discoveries in twisted graphene bilayers, and transition metal dichalcogenide (TMD) homo- and hetero-bilayers. However, a largely unexplored factor is the interlayer distance, d, which can impact the interlayer coupling strength exponentially. In this letter, we quantitatively 2 determine the coupling strengths as a function of interlayer spacing at various critical points of the Brillouin zone in bilayer MoS2. The exponential dependence of the coupling parameter on the gap distance is demonstrated. Most significantly, we achieved a 280% enhancement of K-valley coupling strength with an 8% reduction of the vdW gap, pointing to a new strategy in designing a novel electronic system in vdW bilayers. gning a unique electronic system in vdW bilayers.This research was primarily supported by the NSF Materials Research Science and Engineering Centers (MRSEC) under DMR-1720595. We also acknowledge support from the Welch Foundation (F-1672 and F-1662), the US NSF (DMR-1808751) and the U.S. Air Force (FA2386-18-1-4097). C.-R.P., P.-J.C., and M.-Y.C. acknowledge the support from Academia Sinica, Taiwan. W.-H.C. acknowledges the support from the Ministry of Science and Technology of Taiwan (MOST-110-2119-M-A49-001-MBK) and the support from the Center for Emergent Functional Matter Science (CEFMS) of NYCU supported by the Ministry of Education of Taiwan. W.-T.H. acknowledges the support from the Ministry of Science and Technology of Taiwan (MOST-110-2112-M-007-011-MY3) and the Yushan Young Scholar Program from the Ministry of Education of Taiwan. C.K.S. also acknowledge the Yushan Scholar Program from the Ministry of Education of Taiwan.Center for Dynamics and Control of Material

Wdpcp, a PCP Protein Required for Ciliogenesis, Regulates Directional Cell Migration and Cell Polarity by Direct Modulation of the Actin Cytoskeleton

Planar cell polarity (PCP) regulates cell alignment required for collective cell movement during embryonic development. This requires PCP/PCP effector proteins, some of which also play essential roles in ciliogenesis, highlighting the long-standing question of the role of the cilium in PCP. Wdpcp, a PCP effector, was recently shown to regulate both ciliogenesis and collective cell movement, but the underlying mechanism is unknown. Here we show Wdpcp can regulate PCP by direct modulation of the actin cytoskeleton. These studies were made possible by recovery of a Wdpcp mutant mouse model. Wdpcp-deficient mice exhibit phenotypes reminiscent of Bardet-Biedl/Meckel-Gruber ciliopathy syndromes, including cardiac outflow tract and cochlea defects associated with PCP perturbation. We observed Wdpcp is localized to the transition zone, and in Wdpcp-deficient cells, Sept2, Nphp1, and Mks1 were lost from the transition zone, indicating Wdpcp is required for recruitment of proteins essential for ciliogenesis. Wdpcp is also found in the cytoplasm, where it is localized in the actin cytoskeleton and in focal adhesions. Wdpcp interacts with Sept2 and is colocalized with Sept2 in actin filaments, but in Wdpcp-deficient cells, Sept2 was lost from the actin cytoskeleton, suggesting Wdpcp is required for Sept2 recruitment to actin filaments. Significantly, organization of the actin filaments and focal contacts were markedly changed in Wdpcp-deficient cells. This was associated with decreased membrane ruffling, failure to establish cell polarity, and loss of directional cell migration. These results suggest the PCP defects in Wdpcp mutants are not caused by loss of cilia, but by direct disruption of the actin cytoskeleton. Consistent with this, Wdpcp mutant cochlea has normal kinocilia and yet exhibits PCP defects. Together, these findings provide the first evidence, to our knowledge, that a PCP component required for ciliogenesis can directly modulate the actin cytoskeleton to regulate cell polarity and directional cell migration

Optimal-Quality Choice and Committed Delivery Time in Build-To-Order Supply Chain

This paper studies a build-to-order supply chain (BTO-SC), which consists of one contract manufacturer (CM) and one original equipment manufacturer (OEM). The CM commits to the delivery time and the OEM determines the quality level and the selling price of the supply chain product. We present a three-stage Stackelberg game model and identify a Nash equilibrium solution for the decisions of the CM and the OEM. We conduct a sensitivity analysis to provide insights into the roles of the CM and the OEM. Our main research findings are as follows: The CM’s profit increases while the OEM’s profit first decreases and then increases (non-monotonic) as the committed delivery time sensitivity of demand increases. Interestingly, this study finds that the OEM’s profit decreases, whereas the CM’s profit first increases and then decreases (non-monotonic) in the unit production subsidy paid by the OEM to the CM. Our work shows that the high-quality and fast-delivery product policy is worthwhile in a quality-sensitive or delivery time-sensitive market, which leads to a triple-win outcome. Counterintuitively, a high production capacity is not always advantageous for the supply chain product, even for the CM