We find that the tetrapeptide GluGluLeuGlu binds to one of the three polybasic cleavage sites of the SARS-CoV-2 spike protein lessening by 34% the RBD-ACE2 binding strength. This significant binding energy reduction demonstrates the feasibility to neutralize RBD-ACE2 binding by targeting this specific polybasic cleavage site. Our work enhances understanding of the binding mechanism of SARS-CoV-2 to ACE2, which may aid the design of therapeutics for COVID-19 infection.Integrated photonics aims at on-chip controlling light in the micro- and nanoscale ranges utilizing the waveguide circuits, which include such basic elements as splitters, multiplexers, and phase shifters. Several photonic platforms, including the well-developed silicon-on-insulator and surface-plasmon polaritons ones, operate well mostly in the IR region. However, operating in the visible region is challenging because of the drawbacks originating from absorption or sophisticated fabrication technology. Recently, a new promising all-dielectric platform based on Bloch surface electromagnetic waves (BSWs) in multilayer structures and functioning in the visible range has emerged finding a lot of applications primarily in sensing. Here, we show the effect of multimode interference (MMI) of BSWs and propose a method for implementing the advanced integrated photonic devices on the BSW platform. We determine the main parameters of MMI effect and demonstrate the operation of Mach-Zehnder interferometers with a predefined phase shift proving the principle of MMI BSW-based photonics in the visible spectrum. Our research will be useful for further developing a versatile toolbox of the BSW platform devices which can be essential in integrated photonics, lab-on-chip, and sensing applications.Manipulation of particles in a controllable manner is highly desirable in many applications. Inspired by biological cilia, this article experimentally and numerically demonstrates a versatile particle transportation platform consisting of arrays of magnetic artificial cilia (MAC) actuated by a rotating magnet. By performing a tilted conical motion, the MAC are capable of transporting particles on their tips, along designated directions that can be fully controlled by the externally applied magnetic field, in both liquid and air, at high resolution (particle precision), with varying speeds and for a range of particle sizes. Moreover, the underlying mechanism of the controlled particle transportation is studied in depth by combining experiments with numerical simulations. The results show that the adhesion and friction between the particle and the cilia are essential ingredients of the mechanism underlying the multidirectional transportation. This work offers an advanced solution to controllably transport particles along designated paths in any direction over a surface, which has potential applications in diverse fields including lab-on-a-chip devices, in vitro biomedical sciences, and self-cleaning and antifouling.Organic electronic materials play important roles in modern electronic devices such as light-emitting diodes, solar cells, and transistors. Upon interaction with light, these optically active materials can undergo different photophysical and photochemical pathways, providing unique opportunities for optimization of light emission via radiative decay, heat generation via nonradiative decay, and singlet oxygen production or phosphorescence emission via intersystem crossing, all of which open alternative opportunities for their applications in sensing, imaging, and therapy. In this Perspective, we discuss all of the pathways that determine the optical properties of high-performance organic electronic materials, focusing on the optimization of each pathway for photogeneration and relaxation of electronic excited states. We also examine nanoparticle (NP) fabrication techniques tailored to macromolecules and small molecules to render them into NPs with optimized size and distribution for biomedical applications and endow organic electronic materials with water dispersibility and biocompatibility. Lastly, we illustrate the in vitro and in vivo applications of some representative organic electronic materials after optimization of each relaxation pathway.Electronic applications of porous metal-organic frameworks (MOFs) have recently emerged as an important research area. However, there is still no report on using MOF solid electrolytes in iontronics, which could take advantage of the porous feature of MOFs in the ionic transport. In this article, MXene-derived two-dimensional porphyrinic MOF (MX-MOF) films are demonstrated as an electronic-grade proton-conducting electrolyte. Meanwhile, the MX-MOF film shows high quality, chemical stability, and capability of standard device patterning processes (e.g., dry etching and optical and electron beam lithography). Using the commercialized nanofabrication processes, an electric double-layer (EDL) transistor is demonstrated using the MX-MOF film (derived from V2CT x MXene) as an ionic gate and MoS2 film as a semiconducting channel layer. The EDL transistor, operated by applying an electric field to control the interaction between ions and electrons, is the core device platform in the emerging iontronics field. Therefore, The MX-MOF, confirmed as a solid electrolyte for EDL transistor devices, could have a significant impact on iontronics research and development.The tumor microenvironment maintains a sufficient immunosuppressive state owing to the existence of the immunosuppressive factors. The most prominent such factor is transforming growth factor β (TGF-β), which is mainly provided by platelets. Moreover, platelets have been shown to be the main accomplice in assisting tumor metastasis. ABT263 Therefore, blocking tumor-associated platelets is endowed with functions of enhancing immunity and reducing metastasis. Herein, we designed a tumor microenvironment-responsive nitric oxide (NO) release nanoparticle, Ptx@AlbSNO, which was able to specifically and safely co-deliver the antiplatelet agent NO and the chemotherapeutic agent paclitaxel (Ptx) into tumor tissues and inhibit platelet-tumor cell interactions. We discovered that Ptx@AlbSNO could successfully block tumor-specific platelet functions, thereby suppressing the process of tumor epithelial-mesenchymal transition (EMT), preventing platelet adhesion around circulating tumor cells (CTCs) and reducing distant metastasis.