Perfect one‐dimensional orientation of zeolite microcrystals on glass can be obtained with very high surface coverage (see Figure), as demonstrated here. The approach, which involves covalently linking the zeolite to the glass, is highly efficient and can be extended to the assembly of zeolite crystals on other supports, such as silica, alumina, and other zeolites.

No abstract

Tear glucose measurements have been suggested as a potential alternative to blood glucose monitoring for diabetic patients. While previous work has reported that there is a correlation between blood and tear glucose levels in humans, this link has not been thoroughly established and additional clinical studies are needed. Herein, we evaluate the potential of using commercial blood glucose test strips to measure glucose in tears. Of several blood glucose strips evaluated, only one brand exhibits the low detection limit required for quantitating glucose in tears. Calibration of these strips in the range of 0-100 μM glucose with an applied potential of 150 mV to the working electrode yields a sensitivity of 0.127 nA/μM and a limit of quantitation (LOQ) of 9 μM. The strips also exhibit ≤13% error (n = 3) for 25, 50, and 75 μM glucose in the presence of 10 μM acetaminophen, 100 μM ascorbic acid, and 100 μM uric acid. Measurements of glucose in tears from nine normal (nondiabetic) fasting human subjects using strips yielded glucose values within the range of 5-148 μM (mean = 47 μM, median = 43 μM), similar to those for human tears reported by others with more complex LC-MS methods. The glucometer strip method could facilitate more clinical studies to determine whether tear glucose and blood glucose levels sufficiently correlate for application to routine measurements in tears to supplement blood glucose testing. This would be especially helpful for children, adolescents, other Type 1 diabetics, and also for Type 2 diabetics who require treatment with insulin and cannot tolerate multiple finger sticks per day.

A hexagonally ordered mesoporous carbon, CMK-3, was utilized as a support for a Fischer-Tropsch catalyst. Each array of elongated pore structures with Co nanoparticles can be regarded as a nanochannel reactor. Due to the pore confinement and the hydrophobic nature of the support, this catalyst demonstrated excellent catalytic performance.

No abstract

We compared four types of ZIF-8 with varying sizes and shapes to determine their thermal-structural stability and derive appropriate thermal activation conditions and correlation between structural characteristics and adsorption properties. Under air, the ZIF-8 phase for all the samples was converted completely into the zinc oxide phase above ∼300°C, though thermalgravimetric analysis (TGA) indicated that the original structure was stable to ∼300−350°C. Longer exposures (∼30 d) suggested that thermal activation at ∼200°C was appropriate for the removal of guest and/or solvent molecules under air without structural damage. Despite no noticeable change in X-ray diffraction (XRD) patterns after activation at 250°C under air, the resulting BET surface areas and CO 2 adsorption amounts (at 1 bar and 30°C) of ZIF-8s were reduced to ∼44−54 and ∼72−87%, respectively, as compared to those of appropriately activated ZIF-8s. It appears that after the activation at 250°C under air, some Zn and N atoms were dissociated and converted to ZnOH and NOH, respectively, causing the partial structural damage of ZIF-8s.

No abstract

Co3O4 nanoparticles (NPs) with a narrow particle size distribution were fabricated via a facile and novel method using mesoporous carbon materials (CMK-3, MSU-F-C) as sacrificial templates. The particle size distribution of the Co3O4 NPs varied depending on the pore size of the templates. Synthesis of the NPs with concurrent complete removal of the templates was achieved at 593 K, which is lower than the temperatures utilized in previous reports. It was verified that the carbon template was decomposed by catalytic oxidation with cobalt and NO x species generated by thermal decomposition of the cobalt nitrate precursor in air. The prepared NPs, and particularly the Co3O4 NPs synthesized from CMK-3, acted as excellent catalysts for the Fischer–Tropsch synthesis (FTS). The high catalytic performance was associated with the optimum particle size (6–10 nm) of the nanoparticles for FTS and enhanced reducibility.