Background and Purpose To provide the first correlative study of the hyperdense MCA sign (HMCAS) and gradient-echo (GRE) MRI blooming artifact (BA) with pathology of retrieved thrombi in acute ischemic stroke. Methods Noncontrast CT and GRE MRI studies prior to mechanical thrombectomy in 50 consecutive cases of acute MCA ischemic stroke were reviewed, blinded to clinical and pathology data. Occlusions retrieved by thrombectomy underwent histopathologic analysis, including automated quantitative and qualitative rating of proportion composed of red blood cells (RBC), white blood cells (WBC), and fibrin on microscopy of sectioned thrombi. Results Among 50 patients, mean age was 66 years and 48% were female. Mean (SD) proportion was 61% (±21) fibrin, 34% (±21) RBC, and 4% (±2) WBC. Of retrieved clots, 22 (44%) were fibrin-dominant, 13 (26%) RBC-dominant and 15 (30%) mixed. HMCAS was identified in 10/20 MCA stroke cases with CT, with mean Hounsfield Unit (HU) density of 61 (SD±8). BA occurred in 17/32 with GRE MRI. HMCAS was more commonly seen with RBC-dominant and mixed than fibrin-dominant clots (100% vs. 67% vs. 20%, p=0.016). Mean percent RBC composition was higher in clots associated with HMCAS (47% vs. 22%, p=0.016). BA was more common in RBC-dominant and mixed clots compared to fibrin-dominant clots (100% vs. 63% vs. 25%, p=0.002). Mean percent RBC was greater with BA (42% vs. 23%, p=0.011). Conclusions CT HMCAS and GRE MRI BA reflect pathology of occlusive thrombus. RBC content determines appearance of HMCAS and BA, whereas absence of HMCAS or BA may indicate fibrin-predominant occlusive thrombi.

The III–V compound semiconductors exhibit superb electronic and optoelectronic properties. Traditionally, closely lattice-matched epitaxial substrates have been required for the growth of high-quality single-crystal III–V thin films and patterned microstructures. To remove this materials constraint, here we introduce a growth mode that enables direct writing of single-crystalline III–V's on amorphous substrates, thus further expanding their utility for various applications. The process utilizes templated liquid-phase crystal growth that results in user-tunable, patterned micro and nanostructures of single-crystalline III–V's of up to tens of micrometres in lateral dimensions. InP is chosen as a model material system owing to its technological importance. The patterned InP single crystals are configured as high-performance transistors and photodetectors directly on amorphous SiO2 growth substrates, with performance matching state-of-the-art epitaxially grown devices. The work presents an important advance towards universal integration of III–V's on application-specific substrates by direct growth.

Supercritical fluid synthesis offers an attractive and unique method to produce metal oxide nanoparticles such as barium strontium titanate (Ba 1−x Sr x TiO 3 with 0 ≤ x ≤ 1). This synthesis pathway has the advantage of producing high quality, highly crystalline nanoparticles in a narrow size range, with accurate control of the elemental composition not easily afforded by other methods of production. Coupled with moderate reaction temperatures and short reaction times, this method could be an environmentally preferred synthesis route compared to conventional synthesis pathways. This paper examines the potential environmental impacts leading from the lab-scale supercritical synthesis of 1 kg of Ba 0.6 Sr 0.4 TiO 3 nanoparticles of an average size 16 nm using the approach of an anticipatory life-cycle assessment. A cradle-to-gate assessment was completed, estimating the impacts across resource extraction, material processing, and production of the nanoparticles, while excluding any associated use-phase or end-of-life considerations.The life-cycle assessment highlights a number of ways by which the environmental profile of the supercritical synthesis of barium strontium titanate nanoparticles could be improved. Lab-scale synthesis was bound by physical constraints of the reactor, whereby the precursor concentration was kept artificially low. Being able to synthesize nanoparticles with precursor concentrations of 0.1 and 1.0 molar would reduce the average life-cycle impacts by nearly 81% and 95%, respectively. Additionally, the recovery and reuse of solvents at high recycling rates (e.g. 90%) could reduce average life-cycle impacts by 56%. At high precursor concentrations and solvent recycling rates, the environmental performance was further limited by the precursors, namely barium and titanium alkoxides, which have high upstream life-cycle demands (i.e. isopropanol production and metal processing). General impact reductions were seen as the ratio of strontium : barium increased. Further reductions could be achieved by replacing the barium, strontium and titanium alkoxides with precursors having better life-cycle profiles such as barium and strontium acetates or barium and strontium hydroxides.