23 research outputs found

    Molecular prototypes for spin-based CNOT quantum gates

    Get PDF
    We show that a chemically engineered structural asymmetry in [Tb2] molecular clusters renders the two weakly coupled Tb3+ spin qubits magnetically inequivalent. The magnetic energy level spectrum of these molecules meets then all conditions needed to realize a universal CNOT quantum gate.Comment: 4 pages, 4 figure

    The configurational energy gap between amorphous and crystalline silicon

    Get PDF
    The crystallization enthalpy of pure amorphous silicon (a-Si) and hydrogenated a-Si was measured by differential scanning calorimetry (DSC) for a large set of materials deposited from the vapour phase by different techniques. Although the values cover a wide range (200-480 J/g), the minimum value is common to all the deposition techniques used and close to the predicted minimum strain energy of relaxed a-Si (240 ± 25 J/g). This result gives a reliable value for the configurational energy gap between a-Si and crystalline silicon. An excess of enthalpy above this minimum value can be ascribed to coordination defects

    Differential light-induced responses in sectorial inherited retinal degeneration.

    Get PDF
    Retinitis pigmentosa (RP) is a group of genetically and clinically heterogeneous inherited degenerative retinopathies caused by abnormalities of photoreceptors or retinal pigment epithelium in the retina leading to progressive sight loss. Rhodopsin is the prototypical G-protein-coupled receptor located in the vertebrate retina and is responsible for dim light vision. Here, novel M39R and N55K variants were identified as causing an intriguing sector phenotype of RP in affected patients, with selective degeneration in the inferior retina. To gain insights into the molecular aspects associated with this sector RP phenotype, whose molecular mechanism remains elusive, the mutations were constructed by site-directed mutagenesis, expressed in heterologous systems, and studied by biochemical, spectroscopic, and functional assays. M39R and N55K opsins had variable degrees of chromophore regeneration when compared with WT opsin but showed no gross structural misfolding or altered trafficking. M39R showed a faster rate for transducin activation than WT rhodopsin with a faster metarhodopsinII decay, whereas N55K presented a reduced activation rate and an altered photobleaching pattern. N55K also showed an altered retinal release from the opsin binding pocket upon light exposure, affecting its optimal functional response. Our data suggest that these sector RP mutations cause different protein phenotypes that may be related to their different clinical progression. Overall, these findings illuminate the molecular mechanisms of sector RP associated with rhodopsin mutations

    Ni Iguals ni Banals

    Full text link
    Projecte: 2018PID-UB/026Ni iguals ni banals és un projecte col·laboratiu entre estudiants de diferents facultats i presentat com un mètode resolutiu per transmetre informació mèdica a la societat. La idea del projecte sorgeix a partir de l’observació de l’ús incorrecte dels fàrmacs de venda lliure i els riscos derivats del seu consum inadequat. L’ibuprofè i el paracetamol són un claríssim exemple, pel que es decideix fer una intervenció, en forma de campanya educativa, orientada a fomentar un consum responsable d’aquests fàrmacs que es poden adquirir sense recepta mèdica. Una anàlisi de l’entorn mostra que la població jove és la que té menys contacte amb el sistema de salut i, per tant, menys oportunitats de rebre indicacions sobre l’ús correcte dels medicaments. A més, els joves formen part del rang d’edat més propens a realitzar auto-consultes en línia. La forma com Ni iguals ni banals pretén donar resposta al problema del mal ús dels fàrmacs és amb la creació d’un producte audiovisual dirigit a la població jove on es defineixin les indicacions específiques del paracetamol i de l’ibuprofè, així com les conseqüències del seu ús incorrecte a causa de les seves similituds farmacològiques. El material audiovisual elaborat té dos propòsits: 1) seduir a la població diana a través de l’elecció del gènere audiovisual més adient, la síntesi de la informació científica i l’ajust del registre verbal divulgatiu i 2) facilitar la seva difusió a través de les xarxes socials. Així mateix, és un format tancat i revisable per professionals abans de la seva difusió i, per tant, factible per a estudiants de Medicina que encara no són facultatius. Ni iguals ni banals és un exemple clar sobre com es pot combinar la identificació d’un problema real mèdic, la recerca d’informació tant poblacional com bibliogràfica i la col·laboració interdisciplinària, per englobar-ho tot en una dinàmica didàctica, de forma que els estudiants adquireixen habilitats pràctiques a la vegada que es desenvolupen en un ambient transversal

    Evaluación del estado nutricional de los pacientes mayores atendidos en una unidad de hospitalización a domicilio Assessment of the nutritional status of elderly patients treated at a home-hospital unit

    No full text
    Objetivos: Establecer el estado nutricional de nuestros pacientes mayores, valorar la utilidad de los distintos parámetros antropométricos y bioquímicos como marcadores de desnutrición y determinar qué variables estudiadas tienen mayor correlación con la malnutrición. Ámbito: Unidad de Hospitalización a Domicilio del Hospital Universitario Arnau de Vilanova de Lleida. Pacientes: 57 pacientes &#8805; 60 años. Media de estancia en nuestra unidad: 12,1 días. Variables: Edad, sexo, grupos según la complejidad de las curas, patología asociada, diagnóstico, motivo de ingreso, tiempo de estancia hospitalaria, intervención quirúrgica practicada, complicaciones durante la estancia en la UHD, peso, talla, PCT, CB, IMC, CMB, albúmina, hemoglobina y RTL. Resultados: Los pacientes de "más edad" presentan una tasa de seroalbúmina (p Goals. To establish the nutritional status of our elderly patients, assess the usefulness of the various anthropometric and biochemical parameters as markers of malnutrition and to determine which of the variables studied have the greatest correlation with malnutrition. Scope: Home Hospital Unit of the Arnau de Vilanova Teaching Hospital in Lerida. Patients: 57 patients &#8805; 60 years. Mean admission to our unit: 12.1 days. Variables: Age, sex, groups by treatment complexity, associated pathology, diagnosis, reason for admission, duration of stay in hospital, surgery performed, complications during the stay at the Home Hospital Unit, weight, height, PCT, AC, BMI, albumin, haemoglobin and RTL. Results: Patients of great age present lower levels of serum albumin (p < 0.005), total proteins (p < 0.001), transferrin (p < 0.03), haemoglobin (p < 0.02) and RTL (p < 0.04) than "younger" elderly patients. Serum albumin and haemoglobin are lower in patients in a complicated post-surgical condition (p < 0.04 and p < 0.02, respectively) and this group is the one with the longest stays (p < 0.001). Those patients with hypoalbuminaemia (74.1%) present lower PCT and RTL (p < 0.02) and a longer stay in hospital (p < 0.01) than those with normal levels of albumin in blood. Patients with anaemia (63.3%) present a lower RTL (p < 0.01) and a greater hospitalization time than those without anaemia. Total proteins (p < 0.0001), albumin (p < 0.004), transferrin (p < 0.003) and RTL (p < 0.005) correlate negatively with age. Albumin (p < 0.001), haemoglobin (p < 0.006) and RTL (p < 0.0001) present a negative correlation with length of hospital stay. Conclusion: The prevalence of global malnutrition is high (51% moderate-severe). The nutritional status worsens with age. The length of hospitalization increases gradually with age, with deterioration in the nutritional status and with complexity of the treatment provided

    The configurational energy gap between amorphous and crystalline silicon

    No full text
    The crystallization enthalpy of pure amorphous silicon (a-Si) and hydrogenated a-Si was measured by differential scanning calorimetry (DSC) for a large set of materials deposited from the vapour phase by different techniques. Although the values cover a wide range (200-480 J/g), the minimum value is common to all the deposition techniques used and close to the predicted minimum strain energy of relaxed a-Si (240 ± 25 J/g). This result gives a reliable value for the configurational energy gap between a-Si and crystalline silicon. An excess of enthalpy above this minimum value can be ascribed to coordination defects

    Psychology

    No full text
    A major challenge for realizing quantum computation is finding suitable systems to embody quantum bits (qubits) and quantum gates (qugates) in a robust and scalable architecture. An emerging bottom-up approach uses the electronic spins of lanthanides. Universal qugates may then be engineered by arranging in a molecule two interacting and <i>different</i> lanthanide ions. Preparing heterometallic lanthanide species is, however, extremely challenging. We have discovered a method to obtain [LnLn′] complexes with the appropriate requirements. Compound [CeEr] is deemed to represent an ideal situation. Both ions have a doubly degenerate magnetic ground state and can be addressed individually. Their isotopes have mainly zero nuclear spin, which enhances the electronic spin coherence. The analogues [Ce<sub>2</sub>], [Er<sub>2</sub>], [CeY], and [LaEr] have also been prepared to assist in showing that [CeEr] meets the qugate requirements, as revealed through magnetic susceptibility, specific heat, and EPR. Molecules could now be used for quantum information processing
    corecore