Surveying colloid sedimentation by coplanar waveguides.

By using coplanar waveguides, direct access to the dielectric properties of aqueous solutions of polystyrene beads with different diameters from 330 nm to 10 µm is provided. The relative variation of the transmission parameter with respect to water is monitored, ranging from [Formula: see text] obtained for a 9.5% solution with 330 nm diameter beads to ∼22% for 10 µm diameter particles at the same concentration. To highlight its applicability in biosensing, the technique was further employed to survey the clustering between biotin and streptavidin-coated beads. The transmission parameter displays a ∼50% increase for mixtures containing nine volumes of biotin and one volume of streptavidin-modified beads (4.5 ng µl(-1) of streptavidin) and reaches ∼400% higher values when equal volumes of biotin and streptavidin-coated beads (22.5 ng µl(-1) of streptavidin) were mixed.

Vertical single nanowire devices based on conducting polymers.

A simple scheme for single conducting polymer nanowire fabrication and device integration is presented. We discuss a combined top-down and bottom-up approach for the sequential, precise manufacture of vertical polyaniline nanowires. The method is scalable and can be applied on rigid as well as on flexible substrates. The kinetics of the template-confined growth is presented and discussed. We further study the electrical behavior of single vertical polyaniline nanowires and address the fabrication of crossbar latches using a criss-cross arrangement of electrodes. The as-synthesized polyaniline nanowires display electric conductivities reaching values as high as 0.4 S cm⁻¹.

Imaging Coulomb islands in a quantum Hall interferometer.

In the quantum Hall regime, near integer filling factors, electrons should only be transmitted through spatially separated edge states. However, in mesoscopic systems, electronic transmission turns out to be more complex, giving rise to a large spectrum of magnetoresistance oscillations. To explain these observations, recent models put forward the theory that, as edge states come close to each other, electrons can hop between counterpropagating edge channels, or tunnel through Coulomb islands. Here, we use scanning gate microscopy to demonstrate the presence of QH Coulomb islands, and reveal the spatial structure of transport inside a QH interferometer. Locations of electron islands are found by modulating the tunnelling between edge states and confined electron orbits. Tuning the magnetic field, we unveil a continuous evolution of active electron islands. This allows to decrypt the complexity of high-magnetic-field magnetoresistance oscillations, and opens the way to further local-scale manipulations of QH localized states.

[Recto-vesical and recto-vesico-vaginal fistulae caused by radiotherapy for carcinoma of the uterine cervix. Surgical treatment]. / Fistulele recto-vezicale si recto-vezico-vaginale postradice dupa neoplasm al colului uterin. Tratament chirurgical.

The authors present a study based on 4 cases of fistulous communication between the terminal digestive tube and the genitourinary tract, which appeared after surgery and radiation therapy for carcinoma of the uterine cervix. The diagnosis criteria (symptoms, clinical and imagistic findings), the objectives of the surgical treatment (external digestive derivation, treatment of the fistula and reconstruction of the digestive tube), the steps of the operation and the early and late postoperative evolution are pointed out. The conclusions are shown at the end.

[Gastrojejunocolic fistula after transmesocolic gastrojejunostomy for stenotic duodenal ulcer]. / Fistula gastro-jejuno-colica dupa gastro-jejunostomie transmezocolica pentru ulcer bulbar stenozant.

The authors are presenting the case of a 53 year-old patient, suffering from type II diabetes mellitus and ankylosing spondylitis, admitted in our clinic in July 1997 for gastrojejunocolic fistula, 5 years after a transmesocolic gastrojejunostomy for obstructive chronic duodenal ulcer. The severe metabolic disorders and the radiologic aspects which led to the diagnosis, as well as the morphopathologic lesions found and the ways to approach the fistula, the stenotic duodenal ulcer and the reconstruction of the digestive continuity in a single surgical procedure are further discussed. The conclusions are shown at the end.

[The potentials for immunization against influenza using liposome-incorporated viral surface antigens]. / Possibilités d'immunisation contre la grippe à l'aide d'antigènes viraux de surface incorporés aux liposomes.

Studies were conducted using uni- and multilamellar liposomes to establish optimum conditions for influenza antigen incorporation in view of their transport to the target cells for experimental influenza prophylaxis in hybrid white mice. Radiometric determinations showed a good level of preparation purification, a good efficiency of incorporation in liposomes of the active biological material, the liposome linked radioactivity distribution among different organs. Charged liposomes induced solid and long lasting resistance against influenza control infection.