Effects of annealing and strain on La_{1-x}Ca_{x}MnO_{3} thin films: a new phase diagram in the ferromagnetic region

Oriented, single phase thin films of La_{1-x}Ca_{x}MnO_{3} have been deposited onto (100)-oriented LaAlO_{3} (0.1<x<0.5) substrates using the Pulsed Laser Deposition technique. While for some compositions the physical properties (transport and magnetization) of the as-grown films are higher than the bulk values, for other calcium contents the optimized properties are obtained only after annealing under oxygen. These data can be partly explained by changes in oxygen content, resulting in cationic vacancies and thus self-doping effects - accompanying structural changes, may be the cause of properties beyond the phase diagram. We propose a new phase diagram for (La_{1-x}Ca_{x})_{1-y}\square_{y}MnO_{3} (0.1<x<0.5) thin films.Comment: 8 pages, 5 figures submitted to Applied Physics Letter

The effect of substrate induced strain on the charge-ordering transition in Nd_{0.5}Sr_{0.5}MnO_{3} thin films

We report the synthesis and characterization of Nd_{0.5}Sr_{0.5}MnO_{3} thin films grown by the Pulsed Laser Deposition technique on 100 -oriented LaAlO_{3} substrates. X-ray diffraction (XRD) studies show that the films are 101 -oriented, with a strained and quasi-relaxed component, the latter increasing with film thickness. We observe that transport properties are strongly dependent on the thickness of the films. Variable temperature XRD down to 100 K suggests that this is caused by substrate induced strain on the films.Comment: 3 pages REVTeX, 4 figures included, submitted to AP

Coexistence of Antiferromagnetism and Superconductivity in Electron-doped High-Tc Superconductors

We present magnetotransport evidence for antiferromagnetism in films of the electron-doped cuprates Pr$_{2-x}$Ce$_x$CuO$_4$. Our results show clear signature of static antiferromagnetism up to optimal doping x=0.15, with a quantum phase transition close to x=0.16, and a coexistence of static antiferromagnetism and superconductivity for 0.12$\le$x$\le$0.15

Local tunneling spectroscopy of the electron-doped cuprate Sm1.85Ce0.15CuO4

We present local tunneling spectroscopy in the optimally electron-doped cuprate Sm2-xCexCuO4 x=0.15. A clear signature of the superconducting gap is observed with an amplitude ranging from place to place and from sample to sample (Delta~3.5-6meV). Another spectroscopic feature is simultaneously observed at high energy above \pm 50meV. Its energy scale and temperature evolution is found to be compatible with previous photoemission and optical experiments. If interpreted as the signature of antiferromagnetic order in the samples, these results could suggest the coexistence on the local scale of antiferromagnetism and superconductivity on the electron-doped side of cuprate superconductors

The Penguin: a Low Reynolds Number Powered Glider for Station Keeping Missions

The Penguin is a low Reynolds number (approx. 100,000) remotely piloted vehicle (RPV). It was designed to fly three laps indoors around two pylons in a figure-eight course while maximizing loiter time. The Penguin's low Reynolds number mission is an important one currently being studied for possible future flights in the atmospheres of other planets and for specialized military missions. Although the Penguin's mission seemed quite simple at first, the challenges of such low Reynolds number flight have proven to be quite unique. In addition to the constraint of low Reynolds number flight, the aircraft had to be robust in its control, highly durable, and it had to carry a small instrument package. The Penguin's flight plan, concept, performance, aerodynamic design, weight estimation, structural design, propulsion, stability and control, and cost estimate is detailed

Preferential mobilization and egress of Type 1 and Type 3 innate lymphocytes in response to exercise and hypoxia

The study examined the effect of exercise and hypoxia on the mobilization and egress of innate lymphocytes (ILCs) and adaptive T cell populations in the blood. The ILCs have emerged as a critical population of cells in immune regulation at mucosal surfaces in animals and humans. Eleven healthy male subjects performed (i) 45 min of exercise at 50% VO2 peak on a cycle ergometer under normoxia and (ii) hypoxia, or (iii) while resting in hypoxia. Blood samples were obtained pre-exercise, immediately post-exercise and 60 min post-exercise and were analyzed by flow cytometry to examine the type 1 and type 3 ILCs and CD4+ and CD8+ naive and memory cell populations. There was a significant increase in the number of type 1 (NK cells) and type 3 ILC22 cells in the blood in response to exercise under normal oxygen conditions followed by a significant egress of these cells following the cessation of exercise. Exercise performed under hypoxic conditions abrogated the mobilization response of NK cells and ILC22 cells. Type 3 LTi cells were mobilized into the blood only under hypoxic rest conditions. No significant changes were observed when we analysed total CD4+ and CD8+T cell populations or the naive and memory subsets. This study highlights that distinct innate populations are mobilised under different environmental conditions and types of stress

Resistance to intercompartmental mass transfer limits β2-microglobulin removal by post-dilution hemodiafiltration

Although clearance of β2-microglobulin is greater with hemodiafiltration than with high-flux hemodialysis, β2-microglobulin concentrations after long-term hemodiafiltration are only slightly less than those obtained with high-flux hemodialysis. Resistance to β2-microglobulin transfer between body compartments could explain this observation. β2-Microglobulin kinetics were determined in patients receiving on-line post-dilution hemodiafiltration for 4 h with 18 l of filtration. Plasma β2-microglobulin concentrations were measured during and for 2 h following hemodiafiltration and immediately before the next treatment. The filter clearance of β2-microglobulin was determined from arterial and venous concentrations. The β2-microglobulin generation rate was calculated from the change in the plasma concentration between treatments. The intercompartmental clearance was obtained by fitting the observed concentrations to a two-compartment, variable volume model. The plasma clearance of β2-microglobulin by the filter was 73±2 ml/min. Plasma β2-microglobulin concentrations decreased by 68±2% from pre- to post-treatment (27.1±2.2–8.5±0.7 mg/l), but rebounded by 32±3% over the next 90 min. The generation rate of β2-microglobulin was 0.136±0.008 mg/min. The model fit yielded an intercompartmental clearance of 82±7 ml/min and a volume of distribution of 10.2±0.6 l, corresponding to 14.3±0.7% of body weight. Hemodiafiltration provides a β2-microglobulin clearance of similar magnitude to the intercompartmental clearance within the body. As a result, intercompartmental mass transfer limits β2-microglobulin removal by hemodiafiltration. This finding suggests that alternative strategies, such as increased treatment times or frequency of treatment, are needed to further reduce plasma β2-microglobulin concentrations