Sistema y procedimiento de inspección de superficies de estructuras micro y nanomecánicas

Sistema de inspección de superficies dispuesto para detectar características de desplazamiento relativo y/o de vibración de diversos puntos de una pluralidad de elementos (51) que forman parte de una estructura mecánica (5), comprendiendo dicho sistema: una fuente de luz (1) dispuesta para generar, al menos, un haz de luz (11); un detector sensible a la posición (2) dispuesto para recibir el haz de luz cuando es reflejado fuera de la estructura mecánica (5) y para generar, al menos, una señal de salida en respuesta a la recepción de dicho haz de luz; un sistema de control electrónico (3); un medio de exploración (4) para el desplazamiento relativo de dicho haz de luz con relación a la estructura mecánica (5) con el fin de explorar dicha estructura mecánica con el haz de luz, siguiendo las instrucciones del sistema de control electrónico (3); caracterizado porque dicho sistema de control electrónico (3) está dispuesto para controlar el medio de exploración (4) con el fin de desplazar el haz de luz por la estructura mecánica a lo largo de una primera trayectoria (A) con objeto de detectar una pluralidad de posiciones de referencia subsiguientes (C), cada una en un elemento, a lo largo de dicha primera trayectoria (A), en el que dicho sistema de control electrónico (3) está asociado operativamente con dicho detector sensible a la posición (2) para determinar dichas posiciones de referencia (C) como resultado de un análisis de, al menos, una señal de salida de dicho detector sensible a la posición (2); en el que dicho sistema de control electrónico (3) está dispuesto además para controlar el medio de exploración (4) para desplazar el haz de luz por la estructura mecánica a lo largo de una pluralidad de segundas trayectorias (B), estando asociada cada una de dichas segundas trayectorias (B) con una de dichas posiciones de referencia (C); dicho sistema de control electrónico está dispuesto además para obtener, durante el desplazamiento del haz de luz a lo largo de cada una de dichas segundas trayectorias (B), una pluralidad de salidas de señales de posición de dicho detector sensible a la posición (2).Peer reviewedConsejo Superior de Investigaciones Científicas (España)T3 Traducción de patente europe

Procedimiento de bioanálisis de moléculas de ácido nucleico en una muestra y biosensor para su implementación

Peer reviewedConsejo Superior de investigaciones CientíficasT3 Traducción de patente europe

Effect of the adsorbate stiffness on the resonance response of microcantilever sensors

The authors present a theoretical model to predict the resonance frequency shift due to molecule adsorption on micro- and nanocantilevers. They calculate the frequency shift experienced by cantilevers made of either silicon or the polymer SU-8, when two adsorbates, myosin protein and an alkanethiol, are attached to the cantilever surface. They demonstrate that the effect of the adsorbate stiffness can be comparable or even larger than the mass effect, producing positive frequency shifts. The results provide methods for decoupling both opposite effects and routes for the design of resonators with high sensitivity to molecule adsorption based on either stiffness or mass effects.Peer reviewe

Origin of the response of nanomechanical resonators to bacteria adsorption

Resonant microcantilevers are being actively investigated as sensitive mass sensors for biological detection. By performing experiments of adsorption of the bacteria Escherichia coli on singly clamped microcantilevers, we demonstrate that the effect of the added mass is not the only and may not be the main origin of the response of these sensors. The experiments show that the magnitude and sign of resonance frequency shift both depend critically on the distribution of the adsorbed bacterial cells on the cantilever. We relate this behavior to the added mass that shifts the resonance to lower frequencies and the higher effective flexural rigidity of the cantilever due to the bacteria stiffness that shifts the resonance to higher frequencies. Both effects can be uncoupled by positioning the cells where each effect dominates, near the free cantilever end for measuring the added mass or near the clamping for measuring the increase of flexural rigidity.One of the authors (D.R.) acknowledges the fellowship funded by the Autonomic Community of Madrid. This work was supported by the Spanish National Research Council (CSIC), Project No. 200550M056.Peer reviewe

A protein with simultaneous capsid scaffolding and dsRNA-binding activities enhances the birnavirus capsid mechanical stability

Viral capsids are metastable structures that perform many essential processes; they also act as robust cages during the extracellular phase. Viruses can use multifunctional proteins to optimize resources (e.g., VP3 in avian infectious bursal disease virus, IBDV). The IBDV genome is organized as ribonucleoproteins (RNP) of dsRNA with VP3, which also acts as a scaffold during capsid assembly. We characterized mechanical properties of IBDV populations with different RNP content (ranging from none to four RNP). The IBDV population with the greatest RNP number (and best fitness) showed greatest capsid rigidity. When bound to dsRNA, VP3 reinforces virus stiffness. These contacts involve interactions with capsid structural subunits that differ from the initial interactions during capsid assembly. Our results suggest that RNP dimers are the basic stabilization units of the virion, provide better understanding of multifunctional proteins, and highlight the duality of RNP as capsidstabilizing and genetic information platformsThis work was supported by grants from the Spanish Ministry of Economy and Competitivity (FIS2011-29493 to PJP, BFU2011-29038 to JLC and BFU2014-55475R to JRC) and Comunidad Autónoma de Madrid (S2013/MIT-2850 to JLC and S2013/MIT-2807 to JRC

Global millimeter VLBI array survey of ultracompact extragalactic radio sources at 86 GHz

Context. Very long baseline interferometry (VLBI) observations at 86 GHz (wavelength, λ = 3 mm) reach a resolution of about 50 μas, probing the collimation and acceleration regions of relativistic outflows in active galactic nuclei (AGN). The physical conditions in these regions can be studied by performing 86 GHz VLBI surveys of representative samples of compact extragalactic radio sources. Aims: To extend the statistical studies of compact extragalactic jets, a large global 86 GHz VLBI survey of 162 compact radio sources was conducted in 2010-2011 using the Global Millimeter VLBI Array (GMVA). Methods: The survey observations were made in a snapshot mode, with up to five scans per target spread over a range of hour angles in order to optimize the visibility coverage. The survey data attained a typical baseline sensitivity of 0.1 Jy and a typical image sensitivity of 5 mJy beam-1, providing successful detections and images for all of the survey targets. For 138 objects, the survey provides the first ever VLBI images made at 86 GHz. Gaussian model fitting of the visibility data was applied to represent the structure of the observed sources and to estimate the flux densities and sizes of distinct emitting regions (components) in their jets. These estimates were used for calculating the brightness temperature (Tb) at the jet base (core) and in one or more moving regions (jet components) downstream from the core. These model-fit-based estimates of Tb were compared to the estimates of brightness temperature limits made directly from the visibility data, demonstrating a good agreement between the two methods. Results: The apparent brightness temperature estimates for the jet cores in our sample range from 2.5 × 109 K to 1.3 × 1012 K, with the mean value of 1.8 × 1011 K. The apparent brightness temperature estimates for the inner jet components in our sample range from 7.0 × 107 K to 4.0 × 1011 K. A simple population model with a single intrinsic value of brightness temperature, T0, is applied to reproduce the observed distribution. It yields T0 = (3.77-0.14+0.10) × 1011 K for the jet cores, implying that the inverse Compton losses dominate the emission. In the nearest jet components, T0 = (1.42-0.19+0.16) × 1011 K is found, which is slightly higher than the equipartition limit of ̃5 × 1010 K expected for these jet regions. For objects with sufficient structural detail detected, the adiabatic energy losses are shown to dominate the observed changes of brightness temperature along the jet. The reduced images and visibility tables (FITS files) and the full Tables 5-7 are only available at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz- bin/qcat?J/A+A/622/A9

Safety of intravenous ferric carboxymaltose versus oral iron in patients with nondialysis-dependent CKD: an analysis of the 1-year FIND-CKD trial.

Background: The evidence base regarding the safety of intravenous (IV) iron therapy in patients with chronic kidney disease (CKD) is incomplete and largely based on small studies of relatively short duration. Methods: FIND-CKD (ClinicalTrials.gov number NCT00994318) was a 1-year, open-label, multicenter, prospective study of patients with nondialysis-dependent CKD, anemia and iron deficiency randomized (1:1:2) to IV ferric carboxymaltose (FCM), targeting higher (400-600 µg/L) or lower (100-200 µg/L) ferritin, or oral iron. A post hoc analysis of adverse event rates per 100 patient-years was performed to assess the safety of FCM versus oral iron over an extended period. Results: The safety population included 616 patients. The incidence of one or more adverse events was 91.0, 100.0 and 105.0 per 100 patient-years in the high ferritin FCM, low ferritin FCM and oral iron groups, respectively. The incidence of adverse events with a suspected relation to study drug was 15.9, 17.8 and 36.7 per 100 patient-years in the three groups; for serious adverse events, the incidence was 28.2, 27.9 and 24.3 per 100 patient-years. The incidence of cardiac disorders and infections was similar between groups. At least one ferritin level ≥800 µg/L occurred in 26.6% of high ferritin FCM patients, with no associated increase in adverse events. No patient with ferritin ≥800 µg/L discontinued the study drug due to adverse events. Estimated glomerular filtration rate remained the stable in all groups. Conclusions: These results further support the conclusion that correction of iron deficiency anemia with IV FCM is safe in patients with nondialysis-dependent CKD