Graphene-based heterostructures display a variety of phenomena that are strongly tunable by electrostatic local gates. Monolayer graphene (MLG) exhibits tunable surface plasmon polaritons, as revealed by scanning nano-infrared experiments. In bilayer graphene (BLG), an electronic gap is induced by a perpendicular displacement field. Gapped BLG is predicted to display unusual effects such as plasmon amplification and domain wall plasmons with significantly larger lifetime than MLG. Furthermore, a variety of correlated electronic phases highly sensitive to displacement fields have been observed in twisted graphene structures. However, applying perpendicular displacement fields in nano-infrared experiments has only recently become possible [Li, H.; Nano Lett. 2020, 20, 3106-3112]. In this work, we fully characterize two approaches to realizing nano-optics compatible top gates bilayer MoS2 and MLG. We perform nano-infrared imaging on both types of structures and evaluate their strengths and weaknesses. Our work paves the way for comprehensive near-field experiments of correlated phenomena and plasmonic effects in graphene-based heterostructures.To enhance the water solubility, oral bioavailability, and tumor targeting of gambogenic acid (GNA), polydopamine nanoparticles (PDA NPs) were prepared to encapsulate and stabilize GNA surface modified by folic acid (FA) and then coated with sodium alginate (GNA@PDA-FA SA NPs) to achieve an antitumor effect by oral administration. GNA@PDA-FA SA NPs exhibited in vitro pH-sensitive release behavior. In vitro cell studies manifested that GNA@PDA-FA NPs had higher cytotoxicity to 4T1 cells compared with raw GNA (IC50 = 2.58 μM vs 7.57 μM). After being modified with FA, GNA@PDA-FA NPs were taken up easily by 4T1 cells. In vivo studies demonstrated that the area under the curve (AUC0→∞) of the plasma drug concentration-time of GNA@PDA-FA SA NPs was 2.97-fold higher than that of raw GNA, along with improving drug distribution in the liver, lung, and kidney tissues. In vivo anti-tumor experiments, GNA@PDA-FA SA NPs significantly inhibited the growth of breast tumors in the 4T1 xenograft breast cancer model via oral administration without obvious toxicity on major organs. Our studies indicated that the GNA@PDA-FA SA NPs modified with FA and coated with SA were a promising drug delivery system for targeting tumor therapy via oral administration.The valley depolarization dynamics of free holes in monolayer transition-metal dichalcogenides are studied by solving the Boltzmann transport equation in real time fully ab inito. While monolayer MoSe2, WS2, WSe2, and MoTe2 possess long hole valley lifetimes due to the spin-valley locking effect, monolayer MoS2 unexpectedly shows ultrafast valley dynamics, with a hole valley lifetime two orders of magnitude shorter than those of the above four materials at room temperature. It is further revealed that the existence of the satellite Γ valley in MoS2 provides an additional hole relaxation path where the Γ valley acts as an intermediate in the hole relaxation between primary K' and K valleys, and moreover, the strong scattering between primary and satellite valleys ensures the ultrafast valley depolarization. By uncovering the pivotal role of the satellite valley, our results may have significant implications for finely controlling valley depolarization in the multivalley materials.Nanosubstrate engineering is an established approach for modulating cellular responses, but it remains infrequently exploited to facilitate the intracellular delivery of nanoparticles (NPs). We report nanoscale roughness of the extracellular environment as a critical parameter for regulating the cellular uptake of NPs. After seeding cells atop a substrate that contains randomly immobilized gold NPs (termed AuNP-S) with sub-10 nm surface roughness, we demonstrate that such cells internalize up to ∼100-fold more poly(ethylene glycol)-coated AuNPs (Au@PEG NPs) than those cells seeded on a conventional flat culture plate. Our result is generalizable to 4 different cell types and Au@PEG NPs modified with 13 different hydrocarbyl functional groups. Conditioning cells to AuNP-S not only leads to upregulation of clathrin- and integrin-related genes, but also supports elevated uptake of Au@PEG NPs via clathrin-mediated endocytosis. Our data suggest a simple and robust method for boosting the intracellular delivery of nanomedicines by nanosubstrate engineering.The preparation of nanoemulsions of triglyceride oils in water usually requires high mechanical energy and sophisticated equipment. Recently, we showed that α-to-β (viz., gel-to-crystal) phase transition, observed with most lipid substances (triglycerides, diglycerides, phospholipids, alkanes, etc.), may cause spontaneous disintegration of microparticles of these lipids, dispersed in aqueous solutions of appropriate surfactants, into nanometer particles/drops using a simple cooling/heating cycle of the lipid dispersion (Cholakova et al. ACS Nano2020, 14, 8594). In the current study, we show that this "cold-burst process" is observed also with natural oils of high practical interest, including coconut oil, palm kernel oil, and cocoa butter. Mean drop diameters of ca. 50-100 nm were achieved with some of the studied oils. From the results of dedicated model experiments, we conclude that intensive nanofragmentation is observed when the following requirements are met (1) The three-phase contact angle at the solid lipid-water-air interface is below ca. 30 degrees. (2) The equilibrium surface tension of the surfactant solution is below ca. 30 mN/m, and the dynamic surface tension decreases rapidly. (3) The surfactant solution contains nonspherical surfactant micelles, e.g., ellipsoidal micelles or bigger supramolecular aggregates. https://www.selleckchem.com/products/sbi-0640756.html (4) The three-phase contact angle measured at the contact line (frozen oil-surfactant solution-melted oil) is also relatively low. The mechanism(s) of the particle bursting process is revealed, and on this basis, the role of all of these factors is clarified and discussed. We explain all main effects observed experimentally and define guiding principles for optimization of the cold-burst process in various, practically relevant lipid-surfactant systems.