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Barley stripe mosaic virus (BSMV) is a promising biotemplate for the mineralization of metal–organic nanorods. Biomineralization of palladium occurs without an external reducing agent; however, the reduction of gold on wild-type BSMV requires a reducing agent. Recently, histidine has been adopted as a capping and reducing agent for the mineralization of gold nanoparticles. BSMV virus-like particles (BSMV-VLPs) tagged with histidine were investigated for direct gold deposition. However, gold nanoparticles were not formed during the mineralization process. Therefore, the aim of this research was to decorate gold nanoparticles onto palladium-coated BSMV (Pd-BSMV). The gold decoration was achieved through the addition of free histidine. X-ray absorption spectroscopy and energy-dispersive X-ray spectroscopy were used to verify the formation of metallic gold, and a kinetic study of the gold decoration process and the pH effect on the morphologies of gold particles was performed. The development of gold-decorated Pd-BSMV will be crucial for therapeutic applications, such as drug delivery, gene therapy, and photothermal therapy. 

Abstract Since the Voyager mission flybys in 1979, we have known the moon Io to be both volcanically active and the main source of plasma in the vast magnetosphere of Jupiter. Material lost from Io forms neutral clouds, the Io plasma torus and ultimately the extended plasma sheet. This material is supplied from Io’s upper atmosphere and atmospheric loss is likely driven by plasma-interaction effects with possible contributions from thermal escape and photochemistry-driven escape. Direct volcanic escape is negligible. The supply of material to maintain the plasma torus has been estimated from various methods at roughly one ton per second. Most of the time the magnetospheric plasma environment of Io is stable on timescales from days to months. Similarly, Io’s atmosphere was found to have a stable average density on the dayside, although it exhibits lateral (longitudinal and latitudinal) and temporal (both diurnal and seasonal) variations. There is a potential positive feedback in the Io torus supply: collisions of torus plasma with atmospheric neutrals are probably a significant loss process, which increases with torus density. The stability of the torus environment may be maintained by limiting mechanisms of either torus supply from Io or the loss from the torus by centrifugal interchange in the middle magnetosphere. Various observations suggest that occasionally (roughly 1 to 2 detections per decade) the plasma torus undergoes major transient changes over a period of several weeks, apparently overcoming possible stabilizing mechanisms. Such events (as well as more frequent minor changes) are commonly explained by some kind of change in volcanic activity that triggers a chain of reactions which modify the plasma torus state via a net change in supply of new mass. However, it remains unknown what kind of volcanic event (if any) can trigger events in torus and magnetosphere, whether Io’s atmosphere undergoes a general change before or during such events, and what processes could enable such a change in the otherwise stable torus. Alternative explanations, which are not invoking volcanic activity, have not been put forward. We review the current knowledge on Io’s volcanic activity, atmosphere, and the magnetospheric neutral and plasma environment and their roles in mass transfer from Io to the plasma torus and magnetosphere. We provide an overview of the recorded events of transient changes in the torus, address several contradictions and inconsistencies, and point out gaps in our current understanding. Lastly, we provide a list of relevant terms and their definitions. 

Abstract Multi‐scale calcium (Ca²⁺) dynamics, exhibiting wide‐ranging temporal kinetics, constitutes a ubiquitous mode of signal transduction. We report a novel endoplasmic‐reticulum (ER)‐targeted Ca²⁺indicator, R‐CatchER, which showed superior kinetics in vitro (k_off≥2×10³ s⁻¹,k_on≥7×10⁶ M⁻¹ s⁻¹) and in multiple cell types. R‐CatchER captured spatiotemporal ER Ca²⁺dynamics in neurons and hotspots at dendritic branchpoints, enabled the first report of ER Ca²⁺oscillations mediated by calcium sensing receptors (CaSRs), and revealed ER Ca²⁺‐based functional cooperativity of CaSR. We elucidate the mechanism of R‐CatchER and propose a principle to rationally design genetically encoded Ca²⁺indicators with a single Ca²⁺‐binding site and fast kinetics by tuning rapid fluorescent‐protein dynamics and the electrostatic potential around the chromophore. The design principle is supported by the development of G‐CatchER2, an upgrade of our previous (G‐)CatchER with improved dynamic range. Our work may facilitate protein design, visualizing Ca²⁺dynamics, and drug discovery.