Contents: (Adv. Mater. 21/2019)

Perovskite Memory DevicesNonvolatile memory devices based on unipolar resistive switching in a solution-processed organo-metal halide perovskite are reported by Keehoon Kang, Takhee Lee, and co-workers in article number 1804841.A facile synthesis of the perovskite layer with a nonhalide precursor allows the reliable fabrication of high-yield cross-bar array memory devices with a desirable ON/OFF ratio and electrical stability, which can potentially open a solution-processing route for realizing high-density resistive random-access memory devices. Stable AngiogenesisIn article number 1808050, V. Prasad Shastri and coworkers describe the formation of a new perfused blood vessel.The stabilization of this neovessel by a mechanically defined hydrogel microenvironment through the recruitment (extravasation) of mechanosensing CD11b + /piezo-1 + cells by this microenvironment is depicted against the backdrop of a hematoxylin-eosinstained image of a skeletal muscle. Ferroelectric NanocompositesA modified Kelvin probe force microscopy method with nanoscale spatial resolution is reported by Qi Li, Jinliang He, and co-workers in article number 1807722 for direct detection of the local polarization at the matrixparticle interface in ferroelectric nanocomposites.The electric susceptibility of the interface is quantitatively probed, which is higher than that of polymer matrix.It is anticipated that the method may help with judicious design and engineering of high-performance ferroelectric polymer nanocomposites. Cancer TheranosticsIn article number 1806444, Zhong-Xing Jiang, Peng Huang, and co-workers synthesize an amphiphile to emulsify perfluorohexane into a nanoemulsion for multimodalimaging-guided photodynamic therapy.The rupture of the nanoemulsion in tumor tissues can render opposite changes of the photoacoustic and fluorescence/ magnetic resonance signals of the amphiphile.Furthermore, the inner perfluorohexane can responsively release oxygen as a fuel supply for highly efficient cancer photodynamic theranostics.