This Account summarizes techniques for carrying out microfabrication of structures with dimensions down to 10 microm in microchannels that are 0.02-2 mm wide. These methods are largely based on the exploitation of laminar flow at low Reynolds number (Re) to control the spatial delivery of reagents. These methods are illustrated by fabrication of fibers, microelectrode arrays, arrays of crystals, and patterns of proteins and cells.

Graphene, the reincarnation of a surface, offers new opportunities in catalytic applications, not only because of its peculiar electronic structure, but also because of the ease of modulating it. A vast number of proposals have been made to support this point, but there has been a lack of a systematic understanding of the different roles of graphene, as many other reviews published have focused on the synthesis and characterization of the various graphene-based catalysts. In this review, we surveyed the vast literature related to various theoretical proposals and experimental realizations of graphene-based catalysts to first classify and then elucidate the different roles played by graphene in solid-state heterogeneous catalysis. Owing to its one-atom thickness and zero bandgap with low density of states around Fermi level, graphene has great potential in catalysis applications. In general, graphene can function as a support for catalysts, a cover to protect catalysts, or the catalytic center itself. Understanding these functions is important in the design of catalysts in terms of how to optimize the electronic structure of the active sites for particular applications, a few case studies of which will be presented for each role.

An SAC Pt/g-C3N4 enables significant deviation from the scaling between the energetics of *N2H and *NH2, promising for ambient electrochemical NH3 synthesis.

Distant failure is the main cause of human cancer-related mortalities. To develop a model for predicting distant failure in non-small cell lung cancer (NSCLC) and cervix cancer (CC) patients, a shell feature, consisting of outer voxels around the tumor boundary, was constructed using pre-treatment positron emission tomography (PET) images from 48 NSCLC patients received stereotactic body radiation therapy and 52 CC patients underwent external beam radiation therapy and concurrent chemotherapy followed with high-dose-rate intracavitary brachytherapy. The hypothesis behind this feature is that non-invasive and invasive tumors may have different morphologic patterns in the tumor periphery, in turn reflecting the differences in radiological presentations in the PET images. The utility of the shell was evaluated by the support vector machine classifier in comparison with intensity, geometry, gray level co-occurrence matrix-based texture, neighborhood gray tone difference matrix-based texture, and a combination of these four features. The results were assessed in terms of accuracy, sensitivity, specificity, and AUC. Collectively, the shell feature showed better predictive performance than all the other features for distant failure prediction in both NSCLC and CC cohorts.

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Recently, developing matchable cathode materials of Zn ion hybrid capacitor still remains difficult owing to insufficient understanding of the charge storage behavior. However, most previous efforts are devoted to explain the effect of oxygen-containing groups without paying attention to graphitic structure. Herein, the charge storage capability and electrochemical kinetics of reduce graphene oxide (rGO) nanosheets are optimized as a function of their surface properties. Beyond the contribution of oxygen-containing groups, an extra contribution from the reversible adsorption/desorption of H + on carbon atom of rGO sheets is confirmed. Electrochemical analysis and density functional theory calculations reveal that H + induces disruption of π cloud in aromatic domain, accompanied by C sp 2 -sp 3 re-hybridization and the distortion/restoration of graphitic structure. The optimal electrochemical performance with a specific capacitance of 245 F g -1 at 0.5 A g -1 with 53% retention at 20 A g -1 is achieved for rGO thermally treated at 200 °C. As a proof-of-concept application, the 3D printed rGO electrode delivers a high areal capacitance of 1011 mF cm -2 and an energy density of 266 μWh cm -2 . The study is believed to broaden the horizons of proton adsorption chemistry and shed light on the design of novel electrode materials.

We use first-principles calculations to systematically explore the potential of transition metal atoms (Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Ru, Rh, Pd, Ag, Ir, Pt, and Au) embedded in buckled monolayer g-CN as single-atom catalysts. We show that clustering of Sc and Ti on g-CN is thermodynamically impeded and that V, Cr, Mn, and Cu are much less susceptible to clustering than the other TM atoms under investigation. Strong bonding of the transition metal atoms in the cavities of g-CN and high diffusion barriers together are responsible for single-atom fixation. Analysis of the CO oxidation process indicates that embedding of Cr and Mn in g-CN gives rise to promising single-atom catalysts at low temperature.

An electrochemical method for growing macroscopic fibers of electrically conductive poly(3-methylthiophene) is described. Single fibers of uniform diameter (∼0.1 to 0.7 millimeter) and length greater than 10 centimeters are grown in a capillary flow cell by electrochemical oxidation of the monomer, 3-methylthiophene. The shapes and diameters of the resulting fibers are determined by the fluid flow pattern in the cell. Straight fibers, sawtooth-shaped fibers, and fibers with tapered necks can be grown by varying the capillary shape.