No abstract

On‐demand drug release: Magnetothermally responsive drug‐encapsulated supramolecular nanoparticles for on‐demand drug release in vivo have been developed. The remote application of an alternative magnetic field heats the magnetic particles that effectively trigger the release of the drug. An acute drug concentration can be delivered to the tumor in vivo, resulting in an improved therapeutic outcome.

Overcoming resistance: Heat-treated cancer cells possess a protective mechanism for resistance and survival. Resistance-free apoptosis-inducing magnetic nanoparticles (RAINs) successfully promote hyperthermic apoptosis, obstructing cell survival by triggering two functional units of heat generation and the release of geldanamycin (GM) for heat shock protein (Hsp) inhibition under an alternating magnetic field (AMF).

Minimizing the use of precious metal catalysts is important in many applications. Single-atom catalysts (SACs) have received much attention because all of the metal atoms can be used for surface reactions. However, SACs cannot catalyze some important reactions that require ensemble sites. Here, Rh catalysts were prepared by treating 2 wt % Rh/CeO hydrothermally at 750 °C for 25 h. Nearly 100% dispersion was obtained, but the surface Rh atoms were not isolated (denoted as ENS). They catalyzed the oxidation of CH or CH at low temperatures, but these oxidations did not occur on the Rh SAC. When the simultaneous oxidation of CO, CH, and CH was performed, the T (temperature at conversion 20%) for CO oxidation increased significantly from 40 °C for sole CO oxidation to 180 °C on SAC due to the competitive adsorption of hydrocarbons. However, T increased much less on ENS, from 60 to 100 °C. ENS exhibited superior activity for low-temperature oxidation. During hydrothermal treatment for 25 h, the Rh size initially increased from 2.3 to 6.7 nm then decreased to 0.9 nm. The surface hydroxyl groups formed on the catalyst surface help detach Rh atoms from Rh clusters, while preventing the reaggregation of dispersed Rh atoms into Rh clusters. This fully dispersed catalyst would have maximum atom-efficiency while catalyzing various surface reactions.

Ceria-supported Pd nanoparticles are known to be efficient catalysts for vehicle exhaust purification, especially diesel oxidation. The exhaust often undergoes harsh conditions, suffering from high temperature up to ∼750 °C. These conditions cause Pd nanoparticles to sinter, losing the catalytic active sites. In addition, carbonate and sulfate species might be formed on the catalyst surface, blocking the active sites with degraded activity. Hydrothermal treatment on Pd/CeO 2 affects the catalyst structure, resulting in enhanced catalytic activity and durability for CO oxidation. CO conversion approached 100% at temperatures lower than 150 °C even in the presence of propylene or SO 2 . The high activity for CO conversion changed little for longer reaction times and even for temperature fluctuations up to 850 °C. A promoting effect was obtained due to Pd redispersion and surface hydroxyl groups formed after the hydrothermal treatment. The redispersion was confirmed by TEM, EXAFS, XRD, in situ DRIFT, and CO chemisorption, and the suppression of surface-poisoning species was investigated using in situ DRIFT and TPD techniques.