2,442 research outputs found

    Bismuth selenide nanostructured clusters as optical coherence tomography contrast agents: beyond gold-based particles

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    Optical coherence tomography (OCT) is an imaging technique currently used in clinical practice to obtain optical biopsies of different biological tissues in a minimally invasive way. Among the contrast agents proposed to increase the efficacy of this imaging method, gold nanoshells (GNSs) are the best performing ones. However, their preparation is generally time-consuming, and they are intrinsically costly to produce. Herein, we propose a more affordable alternative to these contrast agents: Bi2Se3 nanostructured clusters with a desert rose-like morphology prepared via a microwave-assisted method. The structures are prepared in a matter of minutes, feature strong near-infrared extinction properties, and are biocompatible. They also boast a photon-to-heat conversion efficiency of close to 50%, making them good candidates as photothermal therapy agents. In vitro studies evidence the prowess of Bi2Se3 clusters as OCT contrast agents and prove that their performance is comparable to that of GNSsJ.Y. acknowledges the support from the China Scholarship Council (CSC file no. 201704910867). R.M. acknowledges the support of the European Commission through the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie Grant agreement no. 797945 (LANTERNS). This work was supported by the Spanish Ministry of Economy and Competitiveness under projects MAT2017-83111R, MAT2017-85617-R, and PID2019- 106211RB-I00, by the Instituto de Salud Carlos III (PI16/ 00812), by the Comunidad Autonoma de Madrid (B2017/ ́ BMD-3867 RENIM-CM), and cofinanced by the European Structural and Investment Fun

    Eosin Y-functionalized upconverting nanoparticles: nanophotosensitizers and deep tissue bioimaging agents for simultaneous therapeutic and diagnostic applications

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    Functionalized upconverting nanoparticles (UCNPs) are promising theragnostic nanomaterials for simultaneous therapeutic and diagnostic purposes. We present two types of non-toxic eosin Y (EY) nanoconjugates derived from UCNPs as novel nanophotosensitizers (nano-PS) and deep-tissue bioimaging agents employing light at 800 nm. This excitation wavelength ensures minimum cell damage, since the absorption of water is negligible, and increases tissue penetration, enhancing the specificity of the photodynamic treatment (PDT). These UCNPs are uniquely qualified to fulfil three important roles: as nanocarriers, as energy-transfer materials, and as contrast agents. First, the UCNPs enable the transport of EY across the cell membrane of living HeLa cells that would not be possible otherwise. This cellular internalization facilitates the use of such EY-functionalized UCNPs as nano-PS and allows the generation of reactive oxygen species (ROS) under 800 nm light inside the cell. This becomes possible due to the upconversion and energy transfer processes within the UCNPs, circumventing the excitation of EY by green light, which is incompatible with deep tissue applications. Moreover, the functionalized UCNPs present deep tissue NIR-II fluorescence under 808 nm excitation, thus demonstrating their potential as bioimaging agents in the NIR-II biological windo

    Anaplasmosis outbreak in lambs: First report causing carcass condemnation

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    In spring and summer 2020, six outbreaks of condemnation of jaundiced lamb carcasses were diagnosed in different farms in Aragón region, Spain. Anaplasma ovis was identified in all affected farms. Four hundred and ninety-two lambs from two affected farms were more closely examined. Clinical examination, haematologies, biochemistries, histopathology and microbiological and molecular analyses were performed. After slaughter, 34.84% of the lambs showed jaundiced carcasses and 79.64% presented splenomegaly at the abattoir. All tested lambs with icteric carcasses showed positive A. ovis PCR, although 72.72% of the unaffected lambs also tested positive. However, the bacterial load was significantly higher in the animals that showed jaundiced carcasses (Cq: 25.00 vs 26.16; p = 0.004). Moreover, all the tested lambs that showed severe anaemia were PCR positive. On the contrary, the PCR negative lambs did not show anaemia. Lambs that presented icteric carcasses displayed severe regenerative anaemia with significantly lower erythrocyte count (7.18 vs. 11.97), haematocrit (26.89 vs. 34.82) and haemoglobin (8.50 vs. 11.10) than unaffected lambs. Reticulocyte count (18.80 vs. 5.65) was also significantly increased in affected animals. This article describes a new disorder caused by Anaplasma ovis that is producing significant economic losses associated with the carcass condemnation of apparently healthy lamb

    Quantum Zeno and anti-Zeno effects in surface diffusion of interacting adsorbates

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    Surface diffusion of interacting adsorbates is here analyzed within the context of two fundamental phenomena of quantum dynamics, namely the quantum Zeno effect and the anti-Zeno effect. The physical implications of these effects are introduced here in a rather simple and general manner within the framework of non-selective measurements and for two (surface) temperature regimes: high and very low (including zero temperature). The quantum intermediate scattering function describing the adsorbate diffusion process is then evaluated for flat surfaces, since it is fully analytical in this case. Finally, a generalization to corrugated surfaces is also discussed. In this regard, it is found that, considering a Markovian framework and high surface temperatures, the anti-Zeno effect has already been observed, though not recognized as such.Comment: 17 pages, 1 figur

    In vivo near-infrared imaging using ternary selenide semiconductor nanoparticles with an uncommon crystal structure

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    The implementation of in vivo fluorescence imaging as a reliable diagnostic imaging modality at the clinical level is still far from reality. Plenty of work remains ahead to provide medical practitioners with solid proof of the potential advantages of this imaging technique. To do so, one of the key objectives is to better the optical performance of dedicated contrast agents, thus improving the resolution and penetration depth achievable. This direction is followed here and the use of a novel AgInSe2 nanoparticle-based contrast agent (nanocapsule) is reported for fluorescence imaging. The use of an Ag2Se seeds-mediated synthesis method allows stabilizing an uncommon orthorhombic crystal structure, which endows the material with emission in the second biological window (1000–1400 nm), where deeper penetration in tissues is achieved. The nanocapsules, obtained via phospholipid-assisted encapsulation of the AgInSe2 nanoparticles, comply with the mandatory requisites for an imaging contrast agent—colloidal stability and negligible toxicity—and show superior brightness compared with widely used Ag2S nanoparticles. Imaging experiments point to the great potential of the novel AgInSe2-based nanocapsules for high-resolution, whole-body in vivo imaging. Their extended permanence time within blood vessels make them especially suitable for prolonged imaging of the cardiovascular systemJ.Y. acknowledges the support from the China Scholarship Council (CSC File No. 201704910867). R.M. acknowledges the support of the European Commission through the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie Grant Agreement No. 797945 (LANTERNS). P.R. is grateful for a Juan de la Cierva – Incorporación scholarship (IJC2019-041915-I). This work was supported by the Ministerio de Ciencia e Innovación de España under projects MAT2016-75362-C3-1-R, MAT2017-83111R, and MAT2017-85617-R, by the Instituto de Salud Carlos III (PI16/00812), by the Comunidad Autónoma de Madrid (B2017/BMD3867/RENIM-CM, PID2019-106211RB-I00), and cofinanced by the European Structural and investment fund. Additional funding was provided by the European Union Horizon 2020 FETOpen project NanoTBTech (801305), the Fundación para la Investigación Biomédica del Hospital Universitario Ramón y Cajal project IMP18_38 (2018/0265), and also by COST action CA17140. E.X. is grateful for a Juan de la Cierva Formación scholarship (FJC2018-036734-I

    A Practical, One-Pot Synthesis of Highly Substituted Thiophenes and Benzo[b]thiophenes from Bromoenynes and o-Alkynylbromobenzenes

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    An efficient synthesis of thiophenes and benzo[b]thiophenes has been developed from easily available bromoenynes and o-alkynylbromobenzene derivatives. This novel one-pot procedure involves a Pd-catalyzed C–S bond formation using a hydrogen sulfide surrogate followed by a heterocyclization reaction. Moreover, in situ functionalization with selected electrophiles further expands the potential of this methodology to the preparation of the corresponding highly substituted sulfur heterocycles.Junta de Castilla y Leon (BU021A09 and GR-172) and Ministerio de Ciencia e Innovacion (MICINN) and FEDER (CTQ2010-15358 and CTQ2009-09949/BQU) for financial support. P.G.-G. and M.A.F.-R. thank MICINN for "Juan de la Cierva" and "Ramon y Cajal" contractsJunta de Castilla y Leon (BU021A09 and GR-172) and Ministerio de Ciencia e Innovacion (MICINN) and FEDER (CTQ2010-15358 and CTQ2009-09949/BQU) for financial support. P.G.-G. and M.A.F.-R. thank MICINN for "Juan de la Cierva" and "Ramon y Cajal" contractsThis document is the Accepted Manuscript version of a Published Work that appeared in final form in Organic Letters, copyright © American Chemical Society after peer review and technical editing by the publisher

    Pressure-induced phase-transition sequence in CoF2: An experimental and first-principles study on the crystal, vibrational, and electronic properties

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    We report a complete structural study of CoF2 under pressure. Its crystal structure and vibrational and electronic properties have been studied both theoretically and experimentally using first-principles density functional theory (DFT) methods, x-ray diffraction, x-ray absorption at Co K-edge experiments, Raman spectroscopy, and optical absorption in the 0–80 GPa range. We have determined the structural phase-transition sequence in CoF2 and corresponding transition pressures. The results are similar to other transition-metal difluorides such as FeF2 but different to ZnF2 and MgF2, despite that the Co2+ size (ionic radius) is similar to Zn2+ and Mg2+. We found that the complete phase-transition sequence is tetragonal rutile (P42/mnm) → CaCl2 type (orthorhombic Pnnm) → distorted PdF2 (orthorhombic Pbca)+PdF2 (cubic Pa3¯) in coexistence → fluorite (cubic Fm3¯m) → cotunnite (orthorhombic Pnma). It was observed that the structural phase transition to the fluorite at 15 GPa involves a drastic change of coordination from sixfold octahedral to eightfold cubic with important modifications in the vibrational and electronic properties. We show that the stabilization of this high-pressure cubic phase is possible under nonhydrostatic conditions since ideal hydrostaticity would stabilize the distorted-fluorite structure (tetragonal I4/mmm) instead. Although the first rutile → CaCl2-type second-order phase transition is subtle by Raman spectroscopy, it was possible to define it through the broadening of the Eg Raman mode which is split in the CaCl2-type phase. First-principles DFT calculations are in fair agreement with the experimental Raman mode frequencies, thus providing an accurate description for all vibrational modes and elastic properties of CoF2 as a function of pressure

    Calidad de vida y sus factores determinantes en universitarios españoles de Ciencias de la Salud

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    La calidad de vida en la población universitaria adquiere una especial importancia ya que permite obtener información sobre las condiciones de vida de los universitarios y, sobre todo, de cómo éstos las perciben. Objetivo: Evaluar la calidad de vida de los universitarios que cursan estudios en ciencias de la salud y su relación con diferentes factores tales como: hábitos de vida, parámetros antropométricos y la influencia de las distintas variables sobre su percepción. Material y Método: Estudio transversal de una muestra de 1.753 estudiantes de ciencias de la salud de nueve universidades españolas con diseño muestral aleatorio y estatrificado según curso y facultad al que se le aplicó un cuestionaro ad hoc que recogía todas las variables a estudio. Resultados: La calidad de vida percibida por los participantes fue Me = 75. Los factores explorados de la calidad de vida se co-relacionaron significativamente con la percepción global de calidad de vida de los estudiantes (p<0,001). Se establecieron 3 dimensiones y el impacto de cada una de ellas sobre la percepción de calidad de vida global fue p<0,001. Los varones percibieron mejor calidad de vida que las mujeres y también los estudiantes con menor Índice de Masa Corporal (IMC). Conclusión: Los universitarios son una población clave para realizar actividades de promoción y prevención de la salud por lo que resulta necesario crear mejores infraestucturas y recursos educativos para mejorar la CV y fomentar hábitos y estilos de vida saludable con especial atención en la alimentación y la realización de una adecuada actividad física.Abstract Introduction: The quality of life of university students acquires special importance because it provides information about their life conditions and especially how they perceive it. Objetive: Evaluate the quality of life of students who are enrolled in health science studies and its relation with the following diverse factors: life and dietetic habits, anthropometric parameters and the influence of distinct variables on their perception. Methods: Transversal study of a sample of 1753 health science degree students of nine Spanish universities with a randomized design and stratified by course and faculty for which we applied an ad hoc questionnaire that considered all study variables. Results: The quality of life (QoL) perceived by the participants had a Median of 75. The factors that were explored about the quality of life correlated significantly with their global perception of it (p<0.001). Three dimensions were established and the impact of each one of them on their global perception of QoL was p<0.001. Men perceived better QoL then women and the students with lower Body Mass Index (BMI). Conclusions: University students are a key population for realizing health promotion and prevention activities therefore it is necessary to develop and provide better infrastructures and educative resources in order to enhance their QoL and to promote healthier habits and life styles with special attention on dietetics habits and the performance of an adequate physical activity

    Coupled C, H, N, S and Fe biogeochemical cycles operating in the continental deep subsurface of the Iberian Pyrite Belt

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    Microbial activity is a major contributor to the biogeochemical cycles that make up the life support system of planet Earth. A 613 m deep geomicrobiological perforation and a systematic multi-analytical characterization revealed an unexpected diversity associated with the rock matrix microbiome that operates in the subsurface of the Iberian Pyrite Belt (IPB). Members of 1 class and 16 genera were deemed the most representative microorganisms of the IPB deep subsurface and selected for a deeper analysis. The use of fluorescence in situ hybridization allowed not only the identification of microorganisms but also the detection of novel activities in the subsurface such as anaerobic ammonium oxidation (ANAMMOX) and anaerobic methane oxidation, the co-occurrence of microorganisms able to maintain complementary metabolic activities and the existence of biofilms. The use of enrichment cultures sensed the presence of five different complementary metabolic activities along the length of the borehole and isolated 29 bacterial species. Genomic analysis of nine isolates identified the genes involved in the complete operation of the light-independent coupled C, H, N, S and Fe biogeochemical cycles. This study revealed the importance of nitrate reduction microorganisms in the oxidation of iron in the anoxic conditions existing in the subsurface of the IPBFP7 Ideas: European Research Council, Grant/Award Number: ERC Advanced Grant #250-35
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