Shifts in the distribution of mass densities is a signature of caloric restriction in Caenorhabditis elegans.

Although the starvation response of the model multicellular organism Caenorhabditis elegans is a subject of much research, there is no convenient phenotypic readout of caloric restriction that can be applicable to large numbers of worms. This paper describes the distribution of mass densities of populations of C. elegans, from larval stages up to day one of adulthood, using isopycnic centrifugation, and finds that density is a convenient, if complex, phenotypic readout in C.

Electrical characterization of graphene synthesized by chemical vapor deposition using Ni substrate.

In this work, the electrical characterization of graphene films grown by chemical vapor deposition (CVD) on a Ni thin film is carried out and a simple relation between the gate-dependent electrical transport and the thickness of the films is presented. Arrays of two-terminal devices with an average graphene film thickness of 6.9 nm were obtained using standard fabrication techniques.

Photocatalytic patterning and modification of graphene.

TiO(2)-based photocatalysis has been widely used to decompose various organic pollutants for the purpose of environmental protection. Such a "green" photochemical process can ultimately degrade organic compounds into CO(2) and H(2)O under ambient conditions. We demonstrate here its extended application on the engineering of single- or few-layer graphene.

Synthesis of few-layer hexagonal boron nitride thin film by chemical vapor deposition.

In this contribution we demonstrate a method of synthesizing a hexagonal boron nitride (h-BN) thin film by ambient pressure chemical vapor deposition on polycrystalline Ni films. Depending on the growth conditions, the thickness of the obtained h-BN film is between ∼5 and 50 nm. The h-BN grows continuously on the entire Ni surface and the region with uniform thickness can be up to 20 μm in lateral size which is only limited by the size of the Ni single crystal grains.

Enhancing the conductivity of transparent graphene films via doping.

We report chemical doping (p-type) to reduce the sheet resistance of graphene films for the application of high-performance transparent conducting films. The graphene film synthesized by chemical vapor deposition was transferred to silicon oxide and quartz substrates using poly(methyl methacrylate). AuCl(3) in nitromethane was used to dope the graphene films and the sheet resistance was reduced by up to 77% depending on the doping concentration.

Work function engineering of graphene electrode via chemical doping.

In this work, we demonstrate that graphene films synthesized by chemical vapor deposition (CVD) method can be used as thin transparent electrodes with tunable work function. By immersing the CVD-grown graphene films into AuCl(3) solution, Au particles were formed on the surface of graphene films by spontaneous reduction of metal ions. The surface potential of graphene films can be adjusted (by up to approximately 0.

Engineering polycrystalline Ni films to improve thickness uniformity of the chemical-vapor-deposition-grown graphene films.

It has been shown that few-layer graphene films can be grown by atmospheric chemical vapor deposition using deposited Ni thin films on SiO(2)/Si substrates. In this paper we report the correlation between the thickness variations of the graphene film with the grain size of the Ni film. Further investigations were carried out to increase the grain size of a polycrystalline nickel film.

In-situ sample rotation as a tool to understand chemical vapor deposition growth of long aligned carbon nanotubes.

A new tool for studying the process of carbon nanotube chemical vapor deposition (CVD) synthesis is described. By rotating the substrate in situ during the CVD process, the orientation of floating nanotubes with respect to the substrate is changed by interaction with the gas stream. Nanotubes lying on the surface of the substrate, however, will maintain their relative orientation.

Controlled formation of sharp zigzag and armchair edges in graphitic nanoribbons.

Graphene nanoribbons can exhibit either quasi-metallic or semiconducting behavior, depending on the atomic structure of their edges. Thus, it is important to control the morphology and crystallinity of these edges for practical purposes. We demonstrated an efficient edge-reconstruction process, at the atomic scale, for graphitic nanoribbons by Joule heating.

Large area, few-layer graphene films on arbitrary substrates by chemical vapor deposition.

In this work we present a low cost and scalable technique, via ambient pressure chemical vapor deposition (CVD) on polycrystalline Ni films, to fabricate large area ( approximately cm2) films of single- to few-layer graphene and to transfer the films to nonspecific substrates. These films consist of regions of 1 to approximately 12 graphene layers. Single- or bilayer regions can be up to 20 mum in lateral size.