Great progress has been made in the preparation and application of multi-shelled hollow micro-/nanostructures during the past decade. However, the synthetic methodologies and potential applications of these novel and interesting materials have not been reviewed comprehensively in the literature. In the current review we first describe different synthetic methodologies for multi-shelled hollow micro-/nanostructures as well as their compositional and geometric manipulation and then review their applications in energy conversion and storage, sensors, photocatalysis, and drug delivery. The correlation between the geometric properties of multi-shelled hollow micro-/nanostructures and their specific performance in relevant applications are highlighted. These results demonstrate that the geometry has a direct impact on the properties and potential applications of such materials. Finally, the emerging challenges and future development of multi-shelled hollow micro-/nanostructures are further discussed.

Trimodally sponge-like macro-/mesoporous titania was prepared by hydrothermal treatment of precipitates of tetrabutyl titanate (Ti(OC4H9)4) in pure water. Effects of hydrothermal time on the phase composition, porosity, and photocatalytic activity of hierarchically porous titania were investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM) and N2 adsorption−desorption measurements. All TiO2 powders prepared at 180 °C showed trimodal pore-size distributions in the macro-/mesoporous region:  fine intraparticle mesopores with peak pore diameters of ca. 3.7−6.9 nm, larger interparticle mesopores with peak pore diameters of ca. 23−39 nm, and macropore with pore diameter of ca. 0.5−3 μm. With increasing hydrothermal time, crystallinity, and average anatase crystallite size, pore size and pore volume increased, while specific surface area decreased. The hierarchically porous titania prepared at 180 °C for 24 h displayed an especially high photocatalytic activity probably due to its special pore−wall structure, and its photocatalytic activity was about three times higher than that of Degussa P-25. This trimodally sponge-like macro-mesostructured titania could find its varieties of potential applications in photocatalysis, catalysis, solar cell, and separation and purification processes. A new concept “biomemitic photocatalysis” has been proposed, which may provide new insight into preparation of advanced photocatalytic materials by mimicking surface structures of plant leaves.

Background: Thrombocytopenia has been implicated in patients infected with severe acute respiratory syndrome coronavirus 2, while the association of platelet count and changes with subsequent mortality remains unclear. Methods: The clinical and laboratory data of 383 patients with the definite outcome by March 1, 2020 in the Central Hospital of Wuhan were reviewed. The association between platelet parameters and mortality risk was estimated by utilizing Cox proportional hazard regression models. Results: Among the 383 patients, 334 (87.2%) were discharged and survived, and 49 (12.8%) died. Thrombocytopenia at admission was associated with mortality of almost three times as high as that for those without thrombocytopenia (P < 0.05). Cox regression analyses revealed that platelet count was an independent risk factor associated with in-hospital mortality in a dose-dependent manner. An increment of per 50 × 10 9 /L in platelets was associated with a 40% decrease in mortality (hazard ratio: 0.60, 95%CI: 0.43, 0.84). Dynamic changes of platelets were also closely related to death during hospitalization. Conclusions: Baseline platelet levels and changes were associated with subsequent mortality.