Procedimientos informáticos para el análisis de datos geográficos.

Sin resume

Cutaneous lesions associated to multiple endocrine neoplasia syndrome type 1

Original article[Abstract] Background  Multiple endocrine neoplasia type 1 (MEN1) is a genetic disease that predisposes to endocrine tumour development. Some cutaneous lesions (angiofibromas, collagenomas, melanosis guttaca, lipomas, melanomas, ‘cafe au lait macules’) have been associated to this syndrome. We compare the prevalence of cutaneous lesion in affected patients with their non‐carrier relatives. Patients and method  We studied 9 patients with MEN1 and 20 non‐carrier, first‐degree relatives. Genetic screening was realized in all of them. Patients were examined by dermatologist, and biopsy was performed when necessary. Results  Patients with MEN1 presented hyperparathyroidism (100%), neuroendocrine tumours of pancreas (66%) and pituitary adenomas (44%); their relatives were free of endocrine features of MEN1. The studied cutaneous lesions were more prevalent in affected patients than in non‐carriers (55.5% vs. 25%; P = 0.029). Odds ratio of developing cutaneous lesions in MEN1 patients was 6.6 (95% confidence interval, 1.09–40.43). The frequency of angiofibromas was lower (22.2%) than the reported in other studies (43–88%), and we did not find any collagenoma. Conclusions  MEN1 is associated to some cutaneous lesions and could be useful for detecting MEN1 carriers in an affected family. Cutaneous lesions should be assessed in MEN1 patients.Instituto de Salud Carlos III; FIS PI051024Xunta de Galicia; PGIDT05PXIC91605P

Objective Quantification of Posterior Capsule Opacification after Cataract Surgery, with Optical Coherence Tomography

PURPOSE: To evaluate posterior capsule opacification (PCO) in humans after cataract surgery with intraocular lens (IOL) implantation, by using optical coherence tomography (OCT-1). METHODS: Sixty-six eyes with PCO and 20 eyes with a normal posterior capsule were analyzed. A 3-mm-long horizontal scan of the posterior capsule was obtained. Measurements at three points and their average were recorded. Intraoperator and interoperator reliabilities were assessed. Investigated was peak intensity (PI) and posterior capsule thickening (PCT), with PCT indicating the distance between two reflectivity spikes, with an approximate axial resolution of 10 microm. Results were compared with visual acuity (VA) and PCO type. RESULTS: Intraoperator reliability was 0.59 and 0.97 for average PI and PCT, respectively. The interoperator concordance correlation coefficient was 0.70 and 0.82 for average PI and PCT, respectively. Median (interquartile range) intensities of the reflectivity spike were 16.88 (dB) (range, 12.88-20.41) and 11.9 (8.58-14.28), respectively, in the PCO and control eyes (P = 0.001). PCT was found in PCO eyes (median: 86.13 microm; range, 46.33-115.33), whereas no second spike appeared in control eyes (P = 0.001). The area under the receiver operating characteristic curve of the average PCT for differentiating pearl-type from fibrosis-type PCO was 0.87 (P = 0.001). For a cutoff point of 55.3 microm, the sensitivity was 97.5%, and the specificity was 69%. Worse VA correlated significantly only with larger PCT (r(o) = 0.66; P = 0.01). CONCLUSIONS: OCT-1 appears useful to quantitate PCO. In addition, this system seems to discriminate between different types of PCO. PCT may be a previously unrecognized factor in VA degradation

Características de la cabaña de bovino de cría en las comarcas catalanas de montaña

Peer Reviewe

Development of laser cladding MCrAlY coatings: high temperature friction and wear behaviour

Temperature can have a significant effect on the extent of wear damage of metallic components. Thermal barrier coatings with MCrAlY (where M=Ni, Co, Fe or combinations) alloys can improve the high temperature tribological and friction wear behaviour. In this work the dry friction and wear behaviour at room temperature and high temperature of new developed NiCoCrAlY and CoNiCrAlY laser cladding coatings were evaluated. Dense coatings, with good metallurgical bonding to the AISI 304 substrate was obtained by coaxial laser cladding tracks (40% overlapping), with previously optimized laser parameters. Tribological tests were performed by sliding wear at room temperature and 500 ºC, with an Al2O3 counterpart in ball on disk configuration tribometer. The wear scar surface was evaluated by scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) microanalysis. The 3D wear track topography was measured by inductive contact profilometer which enabled the wear rate calculation. The microstructure of the coatings consists of - Ni/-NiAl or -Co/-(Co,Ni)Al phases depending on the chemical composition of the alloy, as confirmed by X-ray diffraction (XRD) analysis. The wear test results show a reduction in wear rate at high temperature for all materials tested. For the NiCoCrAlY coating, the high temperature also reduces the friction coefficient, while it significantly increases the friction coefficient of CoNiCrAlY coating. The main damage mode is abrasion and adhesion, caused by oxides and partially-oxidized particles in the contact surface. The coatings and substrate results were compared, resulting in improved wear behaviour.The authors acknowledge the financial support of the Ministry of Science and Innovation of the Government of Spain through research project MAT2011-28492- C03 and the Generalitat Valenciana through ACOMP/2013/114 support. Professor Juan Carlos Pereira Falcón thanks the University of Carabobo for the financial support to pursue his doctoral studies at the UPV

Unitary Gate Synthesis for Continuous Variable Systems

We investigate the synthesis of continuous-variable two-mode unitary gates in the setting where two modes A and B are coupled by a fixed quadratic Hamiltonian H. The gate synthesis consists of a sequence of evolutions governed by Hamiltonian H interspaced by local phase shifts applied to A and B. We concentrate on protocols that require the minimum necessary number of steps and we show how to implement the beam splitter and the two-mode squeezer in just three steps. Particular attention is paid to the Hamiltonian x_A p_B that describes the effective off-resonant interaction of light with the collective atomic spin.Comment: 7 pages, minor text modifications, references adde

Structural identifiability of surface binding reactions involving heterogeneous analyte : application to surface plasmon resonance experiments

Binding affinities are useful measures of target interaction and have an important role in understanding biochemical reactions that involve binding mechanisms. Surface plasmon resonance (SPR) provides convenient real-time measurement of the reaction that enables subsequent estimation of the reaction constants necessary to determine binding affinity. Three models are considered for application to SPR experiments—the well mixed Langmuir model and two models that represent the binding reaction in the presence of transport effects. One of these models, the effective rate constant approximation, can be derived from the other by applying a quasi-steady state assumption. Uniqueness of the reaction constants with respect to SPR measurements is considered via a structural identifiability analysis. It is shown that the models are structurally unidentifiable unless the sample concentration is known. The models are also considered for analytes with heterogeneity in the binding kinetics. This heterogeneity further confounds the identifiability of key parameters necessary for reliable estimation of the binding affinit

On the practicality of time-optimal two-qubit Hamiltonian simulation

What is the time-optimal way of using a set of control Hamiltonians to obtain a desired interaction? Vidal, Hammerer and Cirac [Phys. Rev. Lett. 88 (2002) 237902] have obtained a set of powerful results characterizing the time-optimal simulation of a two-qubit quantum gate using a fixed interaction Hamiltonian and fast local control over the individual qubits. How practically useful are these results? We prove that there are two-qubit Hamiltonians such that time-optimal simulation requires infinitely many steps of evolution, each infinitesimally small, and thus is physically impractical. A procedure is given to determine which two-qubit Hamiltonians have this property, and we show that almost all Hamiltonians do. Finally, we determine some bounds on the penalty that must be paid in the simulation time if the number of steps is fixed at a finite number, and show that the cost in simulation time is not too great.Comment: 9 pages, 2 figure