When Bio Meets Technology: Biohybrid Neural Interfaces.

The development of electronics capable of interfacing with the nervous system is a rapidly advancing field with applications in basic science and clinical translation. Devices containing arrays of electrodes can be used in the study of cells grown in culture or can be implanted into damaged or dysfunctional tissue to restore normal function. While devices are typically designed and used exclusively for one of these two purposes, there have been increasing efforts in developing implantable electrode arrays capable of housing cultured cells, referred to as biohybrid implants. Once implanted, the cells within these implants integrate into the tissue, serving as a mediator of the electrode-tissue interface. This biological component offers unique advantages to these implant designs, providing better tissue integration and potentially long-term stability. Herein, an overview of current research into biohybrid devices, as well as the historical background that led to their development are provided, based on the host anatomical location for which they are designed (CNS, PNS, or special senses). Finally, a summary of the key challenges of this technology and potential future research directions are presented.The authors acknowledge funding from EPSRC (EP/S009000/1 and DTP program), European Union’s Horizon 2020 Research and Innovation Programme under grant agreement No. 732032 (BrainCom) (G.G.M.) and from the King Abdullah University of Science and Technology (KAUST) Office of sponsored Research (OSR) under award No. OSR‑2016‑CRG5‑3003

Promethin is a Conserved Seipin Partner Protein

The M.B. lab is supported by the Deutsche Forschungsgemeinschaft (DFG), Cells-in-Motion Cluster of Excellence (EXC 1003—CiM), University of Münster, Germany. The M.S. lab is funded by an SFB1190 by the DFG and a Volkswagen Stiftung “Life” Grant (93092). M.S. is an Incumbent of the Dr. Gilbert Omenn and Martha Darling Professorial Chair in Molecular Genetics. The J.J.R. lab is supported the Medical Research Council [Research Grant MR/L002620/1] and the Biotechnology and Biological Sciences Research Council [BB/K017772/1]. I.G.C. is supported by an EMBO Long-term Fellowship (ALTF-580-2017). M.E.B. is grateful to the Azrieli Foundation for the award of an Azrieli Fellowship.Peer reviewedPublisher PD

Matching structure and bargaining outcomes in buyer–seller networks

We examine the relationship between the matching structure of a bipartite (buyer-seller) network and the (expected) shares of the unit surplus that each connected pair in this network can create. We show that in different bargaining environments, these shares are closely related to the Gallai-Edmonds Structure Theorem. This theorem characterizes the structure of maximum matchings in an undirected graph. We show that the relationship between the (expected) shares and the tructure Theorem is not an artefact of a particular bargaining mechanism or trade centralization. However, this relationship does not necessarily generalize to non-bipartite networks or to networks with heterogeneous link values

Alkali Doping Leads to Charge-Transfer Salt Formation in a Two-Dimensional Metal–Organic Framework

Efficient charge transfer across metal–organic interfaces is a key physical process in modern organic electronics devices, and characterization of the energy level alignment at the interface is crucial to enable a rational device design. We show that the insertion of alkali atoms can significantly change the structure and electronic properties of a metal–organic interface. Coadsorption of tetracyanoquinodimethane (TCNQ) and potassium on a Ag(111) surface leads to the formation of a two-dimensional charge transfer salt, with properties quite different from those of the two-dimensional Ag adatom TCNQ metal–organic framework formed in the absence of K doping. We establish a highly accurate structural model by combination of quantitative X-ray standing wave measurements, scanning tunnelling microscopy, and density-functional theory (DFT) calculations. Full agreement between the experimental data and the computational prediction of the structure is only achieved by inclusion of a charge-transfer-scaled dispersion correction in the DFT, which correctly accounts for the effects of strong charge transfer on the atomic polarizability of potassium. The commensurate surface layer formed by TCNQ and K is dominated by strong charge transfer and ionic bonding and is accompanied by a structural and electronic decoupling from the underlying metal substrate. The consequence is a significant change in energy level alignment and work function compared to TCNQ on Ag(111). Possible implications of charge-transfer salt formation at metal–organic interfaces for organic thin-film devices are discussed

Donor–acceptor co-adsorption ratio controls the structure and electronic properties of two-dimensional alkali–organic networks on Ag(100)

P.T.P.R. and P.J.B. acknowledge financial support from Diamond Light Source and EPSRC. G.C. acknowledges financial support from the EU through the ERC Grant “VISUAL-MS” (Project ID: 308115). B.S. and R.J.M. acknowledge doctoral studentship funding from the EPSRC and the National Productivity Investment Fund (NPIF). R.J.M. acknowledges financial support via a UKRI Future Leaders Fellowship (MR/S016023/1).The results are presented of a detailed combined experimental and theoretical investigation of the influence of coadsorbed electron-donating alkali atoms and the prototypical electron acceptor molecule 7,7,8,8-tetracyanoquinodimethane (TCNQ) on the Ag(100) surface. Several coadsorption phases were characterized by scanning tunneling microscopy, low-energy electron diffraction, and soft X-ray photoelectron spectroscopy. Quantitative structural data were obtained using normal-incidence X-ray standing wave (NIXSW) measurements and compared with the results of density functional theory (DFT) calculations using several different methods of dispersion correction. Generally, good agreement between theory and experiment was achieved for the quantitative structures, albeit with the prediction of the alkali atom heights being challenging for some methods. The adsorption structures depend sensitively on the interplay of molecule–metal charge transfer and long-range dispersion forces, which are controlled by the composition ratio between alkali atoms and TCNQ. The large difference in atomic size between K and Cs has negligible effects on stability, whereas increasing the ratio of K/TCNQ from 1:4 to 1:1 leads to a weakening of molecule–metal interaction strength in favor of stronger ionic bonds within the two-dimensional alkali–organic network. A strong dependence of the work function on the alkali donor–TCNQ acceptor coadsorption ratio is predicted.Publisher PDFPeer reviewe

Probing the interplay between geometric and electronic structure in a two-dimensional K–TCNQ charge transfer network

Scanning tunnelling microscopy (STM), low energy electron diffraction (LEED), ultraviolet and soft X-ray photoelectron spectroscopy (UPS and SXPS) have been used to characterise the formation of a coadsorption phase of TCNQ and K on Ag(111), while the normal incident X-ray standing waves (NIXSW) technique has been used to obtain quantitative structural information. STM and LEED show that an ordered incommensurate phase is formed in which the K atoms are surrounded by four TCNQ molecules in a ‘windmill’ motif, characteristic of other metal/TCNQ phases, in which the nominal TCNQ : K stoichiometry is 1 : 1. UPS and SXPS data indicate the TCNQ is in a negatively-charged state. NIXSW results show that the carbon core of the TCNQ is essentially planar at a height above the Ag(111) surface closely similar to that found without coadsorbed K. In the presence of TCNQ the height of the K ions above the surface is significantly larger than on clean Ag(111), and the ions occupy sites above ‘holes’ in the TCNQ network. NIXSW data also show that the N atoms in the molecules must occupy sites with at least two different heights above the surface, which can be reconciled by a tilt or twist of the TCNQ molecules, broadly similar to the geometry that occurs in bulk TCNQ/K crystals