We report the results of several nonequilibrium experiments performed on superconducting/normal/superconducting (S/N/S) Josephson junctions containing either one or two extra terminals that connect to normal reservoirs. Currents injected into the junctions from the normal reservoirs induce changes in the electron energy distribution function, which can change the properties of the junction. A simple experiment performed on a 3-terminal sample demonstrates that quasiparticle current and supercurrent can coexist in the normal region of the S/N/S junction. When larger voltages are applied to the normal reservoir, the sign of the current-phase relation of the junction can be reversed, creating a "π-junction." We compare quantitatively the maximum critical currents obtained in 4-terminal π-junctions when the voltages on the normal reservoirs have the same or opposite sign with respect to the superconductors. We discuss the challenges involved in creating a "Zeeman" π-junction with a parallel applied magnetic field and show in detail how the orbital effect suppresses the critical current. Finally, when normal current and supercurrent are simultaneously present in the junction, the distribution function develops a spatially inhomogeneous component that can be interpreted as an effective temperature gradient across the junction, with a sign that is controllable by the supercurrent. Taken as a whole, these experiments illustrate the richness and complexity of S/N/S Josephson junctions in nonequilibrium situations. PACS numbers: 74.50.+r, 85.25.Am, 85.25.Cp

Graphene is a promising material for applications in aqueous electrolyte environments. To explore the impact of such environments on graphene's electrical properties, we performed Hall bar measurements on electrolyte-gated graphene. Assuming a Drude model, we find that the room temperature carrier mobility reaches 7,000 cm 2 /Vs, the highest mobility recorded for graphene in an aqueous electrolyte environment. Our results show that the electrical performance of SiO 2-supported graphene is robust, even in the presence of dissolved ions that introduce additional mechanisms for Coulomb scattering.

The mitotic inhibitor, chloral hydrate, induces ciliary loss in the early embryo phase of Lytechinus pictus. It causes a breakdown of cilia at the junction of the cilium and the basal body known as the basal plate. This leaves the plasma membrane temporarily unsealed. The basal apparatus accessory structures, consisting of the basal body, basal foot, basal foot cap, striated side arm, and striated rootlet, are either misaligned or disintegrated by treatment with chloral hydrate. Furthermore, microtubules which are associated with the basal apparatus are disassembled. Mitochondria accumulate at the base of cilia - underneath the plasma membrane - and show alterations in their structural organization. The accumulation of mitochondria is observed in 40% of all electron micrograph sections while 60% show the areas mostly devoid of mitochondria. The microvilli surrounding a cilium and striated rootlet remain intact in the presence of chloral hydrate. These results suggest that deciliation in early sea urchin embryos by chloral hydrate is caused by combined effects on the ciliary membrane and on microtubules in the cilia. Furthermore, it is suggested that chloral hydrate can serve as a tool to explore the cytoskeletal mechanisms that are involved in cilia motility in the developing sea urchin embryo.

We develop a series expansion for the calculation of the magnetic field near the center of Helmholtz coils and apply the result to a magnet of our design. Our analysis considers geometric details of the coils, the magnetic properties of the form and windings, conductor insulation effects, and several winding imperfections. We also consider the relaxation of coil symmetry which happens when the mean radius of each coil and the coil midplane separation distance are unequal. We compute the field uniformity near the coil's center for three cases, including one where axial symmetry remains but geometric imperfections of the order of 10(-3) of the coil "radius" exist.

To determine the thermal noise limit of graphene biotransistors, we have measured the complex impedance between the basal plane of single-layer graphene and an aqueous electrolyte. The impedance is dominated by an imaginary component but has a finite real component. Invoking the fluctuation-dissipation theorem, we determine the power spectral density of thermally driven voltage fluctuations at the graphene/electrolyte interface. The fluctuations have 1/f(p) dependence, with p = 0.75-0.85, and the magnitude of fluctuations scales inversely with area. Our results explain noise spectra previously measured in liquid-gated suspended graphene devices and provide realistic targets for future device performance.

Using tunneling spectroscopy, we have measured the local electron energy distribution function in the normal part of a superconductor-normal metal-superconductor (SNS) Josephson junction containing an extra lead to a normal reservoir. In the presence of simultaneous supercurrent and injected quasiparticle current, the distribution function exhibits a sharp feature at very low energy. The feature is odd in energy, and odd under reversal of either the supercurrent or the quasiparticle current direction. The feature represents an effective temperature gradient across the SNS Josephson junction that is controllable by the supercurrent.PACS numbers: 74.50.+r, 85.25.Am, 85.25.Cp

There is an ongoing effort to improve the energy storage capacity of graphene-based supercapacitors. These supercapacitors store energy in the electric field between the charge carriers in the graphene and the counter ions in a liquid electrolyte. To characterize this double layer, we use the Hall effect to determine the charge carrier density in graphene as a function of voltage. We disentangle the separate roles of double-layer capacitance (the electrostatic contribution) and quantum capacitance and compare the performance of different electrolytes. Our results highlight the advantages of Hall effect measurements for probing the electrostatics of graphene–electrolyte interfaces.

Cancer is a disease characterized by uncontrolled cell divisions in which the molecular controls for cytoskeletal regulation are bypassed. Cell division is governed by centrosomes, microtubule-organizing cell organelles which are crucial for the organization of the mitotic apparatus during mitosis and cell division. Because centrosome abnormalities are observed in the most common human cancers, we used immunofluorescence and transmission electron microscopy to determine centrosome organization in the human androgenresponsive prostate cancer cell line LNCaP and the androgen-independent prostate cancer cell line DU145. During interphase, centrosomes are located in close vicinity to the outer nuclear membrane, duplicate during S-phase, and become separated to the mitotic poles during the transition from interphase to mitosis. Centrosome regulation is based on a number of different factors which are only partly understood. Hormones play a role during developmental regulation of prostates which might trigger the activation of centrosome proteins and consequent cell divisions in order to ensure tissue growth.