Scanning probe oxidation of SiC, fabrication possibilities and kinetics considerations

The following article appeared in Applied Physics Letters 103.16 (2013): 163109 and may be found at http://scitation.aip.org/content/aip/journal/apl/103/16/10.1063/1.4825265We report the outcome of atomic force microscopy local anodic oxidation experiments on 6H-SiC in air. Oxide thickness can be easily tuned by varying applied voltage and pulse duration. The height and the aspect ratio of single dots produced by single DC pulses are remarkably higher than what was reported previously, with self limiting heights exceeding 100 nm. We propose that the diminished density and the change in chemical composition of the oxide grown on SiC with respect to oxide grown under similar condition on Si cause a drop in the activation energy of oxanions diffusion within the newly formed oxide layer.This work was entirely supported by the Italian Institute of Technology (IIT

Desarrollo de un microscopio de fuerzas atómicas de no contacto en ultra-alto vacío y baja temperatura: Aplicación a superficies de grafeno/Pt(111)

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Física de la Materia Condensada. Fecha de lectura: 03-12-201

China: el gigante ha despertado

“China es un gigante dormido. Dejadlo dormir porque, cuando despierte, el mundo se sacudirá” dijo Napoleón Bonaparte en 1816. Dos siglos después, el gigante ya ha despertado. Actualmente, la República Popular China es la segunda economía del mundo y ha logrado, sin dejar de lado su lugar como potencia regional en Asia, extender su poderío por los cinco continentes. De manera pacífica, y con el softpower como su mayor estrategia, ha sabido ganarse un lugar en la agenda política y económica de cada país con el cual ha iniciado vínculos diplomáticos. En el presente trabajo se analizará el camino recorrido por el gigante asiático en el siglo XX y su transición hacia el siglo XXI. Su sistema político, su relación con los países vecinos, Estados Unidos y Europa; y su política exterior para África, la región latinoamericana y la República Argentina serán los ejes centrales.‘China is a sleeping giant. Let her sleep, for when she wakes she will shake the world’ said Napoleon in 1816. Two centuries later, the giant has awakened. Currently the People's Republic of China is the second largest economy in the world and, without neglecting its place as a regional power in Asia, has extended its power to the five continents. Peacefully, and using the soft power as its main strategy, it has succeeded in gaining a place in the political and economic agenda of each country with which it has initiated diplomatic ties. In the present work the path traveled by the Asian giant in the 20th century and its transition towards the 21st century will be analyzed. The focus will be in its political system, its relationship with the neighboring countries, United States and Europe; and its foreign policy towards Africa, Latin American region and Argentina.Universidad Católica de Santa F

Association between work related stress and health related quality of life: the impact of socio-demographic variables. A cross sectional study in a region of central Italy

The aim of this work is investigate relationship between health-related quality of life and work-related stress and the impact of gender, education level, and age on this relationship. A cross-sectional study was conducted among workers of various setting in Rome and Frosinone. Work-related stress was measured with a demand-control questionnaire and health-related functioning by SF (short form)-12 health survey. There were 611 participants. Men reported high mental composite summary (MCS) and physical composite summary (PCS). In multivariate analysis age, gender (p < 0.001) and job demand (0.045) predicted low PCS. Low MCS predicted poor PCS. Job demand and educational level resulted negatively associated with MCS. In an analysis stratified for age, gender, and educational level, gender and age resulted effect modifier for MCS, gender and education level for PCS. In women increase of decision latitude predict (p = 0.001) an increase in MCS; a low job demand predict high MCS in male (p ≤ 0.001). In younger workers, a lower level of job demand predicted high MCS (<0.001). For PCS, gender and education level resulted effect modifier. In women, high decision latitude predicted higher PCS (p = 0.001) and lower level of job demand results in higher PCS (p ≤ 0.001). Higher educational level resulted predictor of low PCS. Management of risk about work-related stress should consider socio-demographic factors

Control of a two-dimensional electron gas on SrTiO3(111) by atomic oxygen

We report on the formation of a two-dimensional electron gas (2DEG) at the bare surface of (111) oriented SrTiO3. Angle resolved photoemission experiments reveal highly itinerant carriers with a 6-fold symmetric Fermi surface and strongly anisotropic effective masses. The electronic structure of the 2DEG is in good agreement with self-consistent tight-binding supercell calculations that incorporate a confinement potential due to surface band bending. We further demonstrate that alternate exposure of the surface to ultraviolet light and atomic oxygen allows tuning of the carrier density and the complete suppression of the 2DEG.Comment: 5 pages, 4 figure

The cyanobacterial ribosomal-associated protein LrtA from Synechocystis sp. PCC 6803 is an oligomeric protein in solution with chameleonic sequence properties

The LrtA protein of Synechocystis sp. PCC 6803 intervenes in cyanobacterial post-stress survival and in stabilizing 70S ribosomal particles. It belongs to the hibernating promoting factor (HPF) family of proteins, involved in protein synthesis. In this work, we studied the conformational preferences and stability of isolated LrtA in solution. At physiological conditions, as shown by hydrodynamic techniques, LrtA was involved in a self-association equilibrium. As indicated by Nuclear Magnetic Resonance (NMR), circular dichroism (CD) and fluorescence, the protein acquired a folded, native-like conformation between pH 6.0 and 9.0. However, that conformation was not very stable, as suggested by thermal and chemical denaturations followed by CD and fluorescence. Theoretical studies of its highly-charged sequence suggest that LrtA had a Janus sequence, with a context-dependent fold. Our modelling and molecular dynamics (MD) simulations indicate that the protein adopted the same fold observed in other members of the HPF family ( - - - - - ) at its N-terminal region (residues 1–100), whereas the C terminus (residues 100–197) appeared disordered and collapsed, supporting the overall percentage of overall secondary structure obtained by CD deconvolution. Then, LrtA has a chameleonic sequence and it is the first member of the HPF family involved in a self-association equilibrium, when isolated in solution.Ministerio de Economía y Competitividad CTQ2015-64445-RMinisterio de Economía y Competitividad BIO2016-78020-RMinisterio de Economía y Competitividad FIS2014-52212-RMinisterio de Economía y Competitividad BIO2016-75634-PFundación Séneca 19353/PI/1

Epidemiology and direct medical costs of human Leishmaniasis in Italy

INTRODUCTION: Osteoarthrosis is the most prevalent joints disorder and it is also the most frequent cause of physical disability in the elderly. When surgery is not indicated, symptomatic drugs are generally used. These treatments are frequently associated to balneotherapy. In fact, balneotherapy or spa therapy has been widely used in classical medicine as a cure for such diseases. The aim and significance of this study is to evaluate the impact of thermalism in subjects suffering from osteoarthrosis. METHODS: We randomly selected 220 osteoarthrosic subjects (STs = spa treatment subjects), aged from 40 to 90, that usually undergone mud pack therapy and balneotherapy at least once a year. They were enrolled in thermal establishments in the Euganean Basin. We also recruited, as control group, 172 osteoarthrosic subjects (NCs = normal care subjects) that never underwent any spa therapy. A questionnaire, comprehensive of a disability score, was administered by physicians to each subject. RESULTS: STs reported to suffer from osteoarthrosis for more years than NCs. Furthermore STs significantly suffered more than NCs from pain in several joints, and they also showed a more elevated average number of painful joints. In spite of that, STs used less drugs than NCs, and showed a higher degree of disability due to osteoarthrosis (p inf.0.001). CONCLUSION: The regular use of mudpack and balneotherapy seem to improve the wellness, and the spa treatment seems to help the achievement of this goal. In this regard it might be important to encourage new investigations in order to assess in which measure thermal therapy contribute to the wellness improvemen

Collapse of the Mott gap and emergence of a nodal liquid in lightly doped Sr2_2IrO4_4

Superconductivity in underdoped cuprates emerges from an unusual electronic state characterised by nodal quasiparticles and an antinodal pseudogap. The relation between this state and superconductivity is intensely studied but remains controversial. The discrimination between competing theoretical models is hindered by a lack of electronic structure data from related doped Mott insulators. Here we report the doping evolution of the Heisenberg antiferromagnet Sr$_2$IrO$_4$, a close analogue to underdoped cuprates. We demonstrate that metallicity emerges from a rapid collapse of the Mott gap with doping, resulting in lens-like Fermi contours rather than disconnected Fermi arcs as observed in cuprates. Intriguingly though, the emerging electron liquid shows nodal quasiparticles with an antinodal pseudogap and thus bares strong similarities with underdoped cuprates. We conclude that anisotropic pseudogaps are a generic property of two-dimensional doped Mott insulators rather than a unique hallmark of cuprate high-temperature superconductivity

Polyurethane Scaffold vs Fascia Lata Autograft for Hip Labral Reconstruction : Comparison of Femoroacetabular Biomechanics

The integrity of the acetabular labrum is critical in providing normal function and minimizing hip degeneration and is considered key for success in today's hip preservation algorithm. Many advances have been made in labral repair and reconstruction to restore the suction seal. To compare the biomechanical effects of segmental labral reconstruction between the synthetic polyurethane scaffold (PS) and fascia lata autograft (FLA). Our hypothesis was that reconstruction with a macroporous polyurethane implant and autograft reconstruction of fascia lata would normalize hip joint kinetics and restore the suction seal. Controlled laboratory study. Ten cadaveric hips from 5 fresh-frozen pelvises underwent biomechanical testing with a dynamic intra-articular pressure measurement system under 3 conditions: (1) intact labrum, (2) reconstruction with PS after a 3-cm segmental labrectomy, then (3) reconstruction with FLA. Contact area, contact pressure, and peak force were evaluated in 4 positions: 90º of flexion in neutral, 90º of flexion plus internal rotation, 90º of flexion plus external rotation, and 20º of extension. A labral seal test was performed for both reconstruction techniques. The relative change from the intact condition (value = 1) was determined for all conditions and positions. PS restored contact area to at least 96% of intact (≥0.96; range, 0.96-0.98) in all 4 positions, and FLA restored contact area to at least 97% (≥0.97; range, 0.97-1.19). Contact pressure was restored to ≥1.08 (range, 1.08-1.11) with the PS and ≥1.08 (range, 1.08-1.10) with the FLA technique. Peak force returned to ≥1.02 (range, 1.02-1.05) with PS and ≥1.02 (range, 1.02-1.07) with FLA. No significant differences were found between the reconstruction techniques in contact area in any position (P >.06), with the exception that FLA presented greater contact area in flexion plus internal rotation as compared with PS (P =.003). Suction seal was confirmed in 80% of PSs and 70% of FLAs (P = .62). Segmental hip labral reconstruction using PS and FLA reapproximated femoroacetabular contact biomechanics close to the intact state. These findings provide preclinical evidence supporting the use of a synthetic scaffold as an alternative to FLA and therefore avoiding donor site morbidity