Publications by authors named "Varela M"

We measured the chemical and magnetic depth profiles of a single crystalline (La(1-x)Pr(x))(1-y)Ca(y)MnO(3-δ) (x=0.52±0.05, y=0.

View Article and Find Full Text PDF

We report a method to improve the thermal stability, up to 900 °C, of bare-metal (naked) gold nanoparticles supported on top of SiO(2) and SrTiO(3) substrates via ligand-assisted pinning. This approach leads to monodisperse naked gold nanoparticles without significant sintering after thermal annealing in air at 900 °C. The ligand-assisted pinning mechanism is described.

View Article and Find Full Text PDF

Boosting large-scale superconductor applications require nanostructured conductors with artificial pinning centres immobilizing quantized vortices at high temperature and magnetic fields. Here we demonstrate a highly effective mechanism of artificial pinning centres in solution-derived high-temperature superconductor nanocomposites through generation of nanostrained regions where Cooper pair formation is suppressed. The nanostrained regions identified from transmission electron microscopy devise a very high concentration of partial dislocations associated with intergrowths generated between the randomly oriented nanodots and the epitaxial YBa(2)Cu(3)O(7) matrix.

View Article and Find Full Text PDF

Alterations in cerebral blood flow (CBF) are believed to be linked to many of the neurological pathologies that affect neonates and small infants. CBF measurements are nonetheless often difficult to perform in this population, as many techniques rely on radioactive tracers or other invasive methods. In this study, mean global CBF was measured in 21 infants under the age of one, using non-invasive MRI techniques adapted to the neonatal population.

View Article and Find Full Text PDF

We describe a novel chromosome microdeletion at 15q26.1 detected by oligo-array-CGH in a 6-year-old girl presenting with global development delay, epilepsy, autistic behavior and facial dysmorphisms. Although these features are often present in Angelman syndrome, no alterations were present in the methylation pattern of the Prader-Willi-Angelman critical region.

View Article and Find Full Text PDF

Object: Brain tumors are associated with behavioral and neuropsychological effects. Most available data are focused on the posttreatment neurological and cognitive deficits of these patients. The aim of the present study was to investigate the pretreatment neuropsychological and behavioral impairment in children with posterior fossa tumors.

View Article and Find Full Text PDF

Background: While it is generally accepted that monozygotic (MZ) twins are identical with respect to inherited traits, because they share 100% of their genetic material, clinical findings and scientific evidence does not support this belief. In addition to environmental factors and stochastic developmental events, a number of genetic mechanisms, detectable by new techniques in molecular genetics, explain the differences frequently observed in MZ twins.

Case Report: Nine-year-old twin girls requested treatment for a dental malocclusion.

View Article and Find Full Text PDF

Interleukin-6 (IL-6) is one of the most pleiotropic cytokines due to its importance in both innate and adaptive immune responses and other physiological processes. In this study, we identified the zebrafish (Danio rerio) IL-6 homologue by investigating the synteny between the human (Homo sapiens), the fugu (Takifugu rubripes) and the zebrafish genome. Although zebrafish IL-6 showed a low sequence homology with other IL-6 sequences in other species, it presented a high structural similarity to human IL-6.

View Article and Find Full Text PDF

Objective: To study if a 24-h continuous monitoring of temperature reveals information not accessible through conventional care. This included omitted fever peaks and circadian and complexity characteristics that may correlate with specific aetiologies.

Design: Ours was a prospective, observational study.

View Article and Find Full Text PDF

Introduction: The updated guidelines for lupus anticoagulant (LA) diagnosis indicate locally calculate the cut-off values of the index of circulating anticoagulant (ICA) and the clotting time in seconds (s) for mixing studies and % of correction (%C) for confirmatory tests. We assess sensitivity (SEN) and specificity (SPC) of the cut-off values obtained as the 99th percentile from 60 plasmas of healthy individuals.

Methods: We analysed 647 plasmas from patients studied in the last 3 years, and results were revaluated according to the new criteria and cut-off values.

View Article and Find Full Text PDF

Using resonant x-ray spectroscopies combined with density functional calculations, we find an asymmetric biaxial strain-induced d-orbital response in ultrathin films of the correlated metal LaNiO3 which are not accessible in the bulk. The sign of the misfit strain governs the stability of an octahedral "breathing" distortion, which, in turn, produces an emergent charge-ordered ground state with an altered ligand-hole density and bond covalency. Control of this new mechanism opens a pathway to rational orbital engineering, providing a platform for artificially designed Mott materials.

View Article and Find Full Text PDF

Objective: We study the extent to which procalcitonin (Pro-CT) and/or C-reactive protein (CRP) may be helpful in the early triage of febrile patients admitted to a general internal medicine ward.

Methods: This is a prospective, observational study on 62 admitted patients in whom a temperature >38°C had been observed the day before inclusion.

Results: Neither Pro-CT nor CRP was able to discriminate infectious (or bacterial) diseases from the other etiologies as a group, with an area under the ROC curve of 0.

View Article and Find Full Text PDF

Vibrio cholerae utilizes mannitol through an operon of the phosphoenolpyruvate-dependent phosphotransferase (PTS) type. A gene, mtlD, encoding mannitol-1-phosphate dehydrogenase was identified within the 3.9 kb mannitol operon of V.

View Article and Find Full Text PDF

Although the prevalence of rheumatic fever has greatly decreased in developed countries, rheumatic mitral stenosis still causes significant morbidity and mortality. Symptomatic patients have a poor prognosis, with a 0 to 15% 10-year survival rate, particularly if percutaneous or surgical intervention are contraindicated or considered high risk. We present a case of severe rheumatic mitral stenosis with an evolution over 4 decades, in which exceptional venous distention has established.

View Article and Find Full Text PDF

The successful correction of third-order and, more recently, fifth-order aberrations has enormously enhanced the capabilities of the scanning transmission electron microscope (STEM), by not only achieving record resolution, but also allowing near 100% efficiency for electron energy loss spectroscopy, and higher currents for two-dimensional spectrum imaging. These advances have meant that the intrinsic advantages of the STEM, incoherent imaging and simultaneous collection of multiple complementary images can now give new insights into many areas of materials physics. Here, we review a number of examples, mostly from the field of complex oxides, and look towards new directions for the future.

View Article and Find Full Text PDF

BiFeO3 (BFO) multiferroic oxide has a complex phase diagram that can be mapped by using appropriately substrate-induced strain in epitaxial films. By using Raman spectroscopy, we conclusively show that films of the so-called supertetragonal T-BFO phase, stabilized under compressive strain, display a reversible temperature-induced phase transition at about 100 °C, and thus close to room temperature.

View Article and Find Full Text PDF

We cloned a gene, ECL_03329, from the chromosome of Enterobacter cloacae ATCC13047, using a drug-hypersensitive Escherichia coli KAM32 cell as the host. We show here that this gene, designated as emmdR, is responsible for multidrug resistance in E. cloacae.

View Article and Find Full Text PDF

Since the demonstration that almost 80% of human immunodeficiency virus type 1 (HIV-1) infections result from the transmission of a single variant from the donor, biological features similar to those of HIV mucosal transmission have been reported for macaques inoculated with simian immunodeficiency virus (SIV). Here we describe the early diversification events and the impact of challenge doses on viral kinetics and on the number of variants transmitted in macaques infected with the chimeric simian/human immunodeficiency virus SHIV(sf162p4). We show that there is a correlation between the dose administered and the number of variants transmitted and that certain inoculum variants are preferentially transmitted.

View Article and Find Full Text PDF

Plasmonics is a rapidly growing field, yet imaging of the plasmonic modes in complex nanoscale architectures is extremely challenging. Here we obtain spatial maps of the localized surface plasmon modes of high-aspect-ratio silver nanorods using electron energy loss spectroscopy (EELS) and correlate to optical data and classical electrodynamics calculations from the exact same particles. EELS mapping is thus demonstrated to be an invaluable technique for elucidating complex and overlapping plasmon modes.

View Article and Find Full Text PDF

The behavioral and neurochemical adaptations related to chronic 3,4-methylenedioxymethamphetamine (MDMA) treatment are largely unknown. In this study, we assessed whether repeated administration of MDMA would induce (a) context-dependent locomotor sensitization in mice and (b) changes in serotonin 5-HT(2A) and dopamine D₂ receptor functionality as measured by [³⁵S]GTPγS binding. Mice were treated with MDMA (10 mg/kg, intraperitoneally) or saline every other day for 11 days either in their home cages or in the environment where locomotor activity was measured.

View Article and Find Full Text PDF

We show in this article that it is possible to obtain elemental compositional maps and profiles with atomic-column resolution across an InxGa1-xAs multilayer structure from 5th-order aberration-corrected high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) images. The compositional profiles obtained from the analysis of HAADF-STEM images describe accurately the distribution of In in the studied multilayer in good agreement with Muraki's segregation model [Muraki, K., Fukatsu, S.

View Article and Find Full Text PDF

We cloned a gene, sugE, from the chromosome of Enterobacter cloacae ATCC 13047. Analysis of the susceptibilities of the sugE-containing strain (Escherichia coli KAM32/pSUGE28) and sugE-deficient E. cloacae (EcΔsugE) showed that SugE confers resistance to cetyltrimethylammonium bromide, cetylpyridinium chloride, tetraphenylphosphonium, benzalkonium chloride, ethidium bromide, and sodium dodecyl sulfate.

View Article and Find Full Text PDF