Two-dimensional (2D) carbon nanosheets with micro- and/or mesopores have attracted great attention due to unique physical and chemical properties, but well-defined nanoporous carbon nanosheets with tunable thickness and pore size have been rarely realized. Here, we develop a polymer–polymer interfacial self-assembly strategy to achieve hierarchically porous carbon nanosheets (HNCNSs) by integrating the migration behaviors of immiscible ternary polymers with block copolymer (BCP)-directed self-assembly. The balanced interfacial compatibility of BCP allows the migration of a BCP-rich phase to the interface between two immiscible homopolymer major phases (i.e., homopoly­(methyl methacrylate) and homopolystyrene), where the BCP-rich phase spreads thinly to a thickness of a few nanometers to decrease the interfacial tension. BCP-directed coassembly with organic–inorganic precursors constructs an ordered mesostructure. Carbonization and chemical etching yield ultrathin HNCNSs with hierarchical micropores and mesopores. This approach enables facile control over the thickness (5.6–75 nm) and mesopore size (25–46 nm). As an anode material in a potassium ion battery, HNCNSs show high specific capacity (178 mA h g–1 at a current density of 1 A g–1) with excellent long-term stability (2000 cycles), by exploiting the advantages of the hierarchical pores and 2D nanosheet morphology (efficient ion/electron diffusion) and of the large interlayer spacing (stable ion insertion).

Background and Purpose-Elevated blood pressure (BP) is commonly observed in acute ischemic stroke and is known to be associated with hemorrhagic transformation (HT). However, the effect of BP variability on the development of HT is not known well. Methods-A consecutive series of patients with acute ischemic stroke, who were hospitalized within 24 hours of onset and showed no HT on initial gradient echo MRI, were enrolled in this study. BP measurements during the first 72 hours were obtained, and BP variability of each patient was described using various summary parameters: SD, maximum (max), minimum (min), difference between max and min (maxϪmin), average squared difference between successive measurements (sv), and maximum sv (svmax). Results-Of 792 patients meeting the eligibility criteria, 70 (8.8%) developed HT. Among BP variability parameters categorized into quartiles, SBP max , SBP min , SBP maxϪmin , SBP svmax , DBP SD , DBP max , DBP min , DBP maxϪmin , and DBP svmax were significantly associated with HT independent of mean SBP, age, interval from onset to arrival, initial stroke severity, diabetes mellitus, stroke subtype, thrombolysis, initial glucose, and total cholesterol (PϽ0.05 on likelihood ratio test of trend). The analyses about the interaction between thrombolysis and variability parameters showed that the effects of BP variability on the development of HT did not differ by whether patients received thrombolysis or not. Conclusions-Our study suggests that we may consider not only the absolute level of BP but also its variability to prevent hemorrhagic transformation. (Stroke. 2010;41:2512-2518.)