In a physically confined environment, interfacial interactions, symmetry breaking, structural frustration and confinement-induced entropy loss can play dominant roles in determining molecular organization. Here we present a systematic study of the confined assembly of silica-surfactant composite mesostructures within cylindrical nanochannels of varying diameters. Using exactly the same precursors and reaction conditions that form the two-dimensional hexagonal SBA-15 mesostructured thin film, unprecedented silica mesostructures with chiral mesopores such as single- and double-helical geometries spontaneously form inside individual alumina nanochannels. On tightening the degree of confinement, a transition is observed in the mesopore morphology from a coiled cylindrical to a spherical cage-like geometry. Self-consistent field calculations carried out to account for the observed mesostructures accord well with experiment. The mesostructures produced by confined syntheses are useful as templates for fabricating highly ordered mesostructured nanowires and nanowire arrays.

na powder (P172SB, PØchiney) with a specific area of 10.2 m 2 g ±1 , a refractive index of 1.70, and a mean diameter of 0.5 lm. A dispersant (phosphoric ester) is also used to decrease the viscosity and to increase the stability of the suspension. The final mixture is prepared with 80 wt.-% (50 vol.-%) of alumina, dispersant (1.5 wt.-% with respect to alumina) and photoinitiator (5.56 wt.-% with respect to the monomer) mixed in a ball mill for 20 min at 350 rpm.The scraper is based on a 10 mm long scalpel. It is moved at a speed of 1.2 mm s ±1, which corresponds to a shear rate varying from 60 to 24 s ±1 , depending on the layer thickness (from 20 to 50 lm, respectively).The debinding step consists of several heating steps. First, the sample is heated to 120 C (degradation temperature of the polymer) at 60 C h ±1. A slower second temperature gradient of 6 C h ±1 is applied up to 500 C and the temperature is maintained for 30 min. The quick heating of the sintering step is applied by increasing the temperature at 900 C h ±1 to 1550 C. The object to be sintered is kept at this temperature for 5 h, and is then cooled to ambient temperature. Detection of CO and O 2 Using Tin Oxide Nanowire Sensors** By Andrei Kolmakov, Youxiang Zhang, Guosheng Cheng, and Martin Moskovits* Solid-state gas sensors play a major role in semiconductor processing, medical diagnosis, environmental sensing, personal safety, and national security, with economic impact in agriculture, medicine, and in the automotive and aerospace industries.[1±3] Most sensors operate on the basis of the modification of the electrical properties of an active element, normally a metal oxide film, brought about by the adsorption of an analyte on the surface of the sensor. A current major goal in gas sensing is massive parallelism, wherein many sensors, each with its unique chemical properties, are operated together and their outputs processed simultaneously, perhaps using learning strategies like neural networks, so that the overall device operates ªintelligentlyº, mimicking, for example, the complex operation of a mammalian nose and its corresponding brain function. [4] This task implies the need for further miniaturization of the active elements with the simultaneous sensitivity increase to compensate for surface area loss. Here, conventional thin film technology faces its fundamental limits. Promising strategies for achieving the above goal of using many sensing elements restricted to a small volume will likely come out of nanoscience and technology and, specifically, out of a subset of technologies amenable to parallelism and array fabrication that do not sacrifice sensitivity and selectivity. This challenge necessitates several design features to be achieved simultaneously, including the development of new materials, innovation in structure and architecture, and the development of highly sensitive, responsive, and selective, yet ultra-small active elements arranged so as to minimize inter-element cross-talk. [5,6] The high surface-to-volume ratio of nano...

Neural stem cell (NSC) based therapy provides a promising approach for neural regeneration. For the success of NSC clinical application, a scaffold is required to provide three-dimensional (3D) cell growth microenvironments and appropriate synergistic cell guidance cues. Here, we report the first utilization of graphene foam, a 3D porous structure, as a novel scaffold for NSCs in vitro. It was found that three-dimensional graphene foams (3D-GFs) can not only support NSC growth, but also keep cell at an active proliferation state with upregulation of Ki67 expression than that of two-dimensional graphene films. Meanwhile, phenotypic analysis indicated that 3D-GFs can enhance the NSC differentiation towards astrocytes and especially neurons. Furthermore, a good electrical coupling of 3D-GFs with differentiated NSCs for efficient electrical stimulation was observed. Our findings implicate 3D-GFs could offer a powerful platform for NSC research, neural tissue engineering and neural prostheses.