Collective electromagnetic emission from molecular layers on metal nanostructures mediated by surface plasmons

6 págs.; 3 figs.; PACS number s : 73.20.Mf, 78.30. j, 78.67.Bf, 42.25.FxCollective electromagnetic processes stemming from molecular emission close to complex nanostructured metal surfaces pumped at and/or near surface-plasmon resonances are theoretically investigated. A classical electrodynamics model is used to describe macroscopically the surface molecular layer emission. Generalized Fresnel coefficients are analytically obtained for planar surfaces, indeed predicting collective quenching for redshifted emission at given angles. The model is introduced into a scattering formulation based on surface integral equations in order to explore collective spontaneous emission near metallic nanoantennas and surface-enhanced Raman scattering. Frequency-shifted near-field patterns and properly defined enhancement factors are obtained that manifest collective processes and cannot be simply inferred from calculations of near fields at the pump frequency. © 2007 The American Physical Society.This work was supported in part by the Spanish “Ministerio de Educación y Ciencia” Grant Nos. FIS2006-07894 and FIS2004-0108 and “Comunidad de Madrid” Grant No. S-0505/TIC-0191 and V.G.’s Ph.D. scholarshipPeer Reviewe

Surface enhanced fluorescence of anti-tumoral drug emodin adsorbed on silver nanoparticles and loaded on porous silicon

Fluorescence spectra of anti-tumoral drug emodin loaded on nanostructured porous silicon have been recorded. The use of colloidal nanoparticles allowed embedding of the drug without previous porous silicon functionalization and leads to the observation of an enhancement of fluorescence of the drug. Mean pore size of porous silicon matrices was 60 nm, while silver nanoparticles mean diameter was 50 nm. Atmospheric and vacuum conditions at room temperature were used to infiltrate emodin-silver nanoparticles complexes into porous silicon matrices. The drug was loaded after adsorption on metal surface, alone, and bound to bovine serum albumin. Methanol and water were used as solvents. Spectra with 1 μm spatial resolution of cross-section of porous silicon layers were recorded to observe the penetration of the drug. A maximum fluorescence enhancement factor of 24 was obtained when protein was loaded bound to albumin, and atmospheric conditions of inclusion were used. A better penetration was obtained using methanol as solvent when comparing with water. Complexes of emodin remain loaded for 30 days after preparation without an apparent degradation of the drug, although a decrease in the enhancement factor is observed. The study reported here constitutes the basis for designing a new drug delivery system with future applications in medicine and pharmacyThe Secretaria de Estado de Investigacion, Desarrollo e Innovacion (MINECO) (Project FIS2010-15405: Plasmonics: Enhanced Molecular Sensing on Metal Nanostructures (POEMS), Comunidad de Madrid (MICROSERES Project, S2009TIC-1476) and grupo investigación 950247 of the UCM are gratefully acknowledged for their financial support. David Gomez (characterization service from the ICTP-CSIC) is also acknowledged for the FE-SEM image

Valorization of CO2 through the Synthesis of Cyclic Carbonates Catalyzed by ZIFs

One way to exploit CO2 is to use it as a feedstock for the production of cyclic carbonates via its reaction with organic epoxides. As far as we know, there is still no heterogeneous catalyst that accelerates the reaction in a selective, efficient and industrially usable way. Cobalt and zinc-based zeolitic imidazole frameworks (ZIFs) have been explored as heterogeneous catalysts for this reaction. In particular, we have prepared ZIF-8 and ZIF-67 catalysts, which have been modified by partial replacement of 2-methylimidazole by 1,2,4-triazole, in order to introduce uncoordinated nitrogen groups with the metal. The catalysts have shown very good catalytic performance, within the best of the heterogeneous catalysts tested in the cycloaddition of CO2 with epichlorohydrin. The catalytic activity is due ultimately to defects on the outer surface of the crystal, and varies in the order of ZIF-67-m > ZIF-67 > ZiF-8-m = ZIF-8. Notably, reactions take place under mild reaction conditions and without the use of co-catalysts.The authors acknowledge financial support by MINECO (Spain) through the projects MAT2017-86992-R and CTQ2017-88171-P, “Ministerio de Ciencia e innovación” (PID2020-116998RB-I00), Ministerio de Educación y Formación Profesional (PRX21/00407), and Conselleria de Innovacion, Universidades, Ciencia y Sociedad Digital (CIPROM/2021/022, MFA/2022/048)

Characterization of scintillator screens under irradiation of low energy 133Cs ions

An imaging heavy ion beam probe (i-HIBP) diagnostic, for the simultaneous measurement of plasma density, magnetic field and electrostatic potential in the plasma edge, has been installed at ASDEX Upgrade. Unlike standard heavy ion beam probes, in the i-HIBP the probing (heavy) ions are collected by a scintillator detector, creating a light pattern or strike-line, which is then imaged by a camera. Therefore, a good characterization of the scintillator response is needed. Previous works focused on the scintillator behaviour against irradiation with light ions such as hydrogen and alpha particles. In this work we present the characterization of several scintillator screens - TG-Green (SrGa2S4:Eu2+), YAG-Ce (Y3Al5O12:Ce3+) and P11 (ZnS:Ag) - against irradiation with 133Cs+ ions, in an energy range between 5 and 70 keV and ion currents between 105 and 107 ions/(s·cm2). Three main properties of the scintillators have been studied: the ionolumenescence efficiency or yield, the linearity and the degradation as a function of the fluence. The highest yield was delivered by the TG-Green scintillator screen with > 8·103 photons/ion at 50 keV. All the samples showed a linear response with increasing incident ion flux. The degradation was quantified in terms of the fluence F1/2, which leads to a reduction of the emissivity by a factor of 2. TG-Green showed the lowest degradation with F1/2= 5.4·1014 ions/cm2. After the irradiation the samples were analyzed by Scanning Electron Microscopy (SEM), Rutherford Backscattering Spectrometry (RBS) and Particle Induced X-ray Emission (PIXE). No trace of Cs was found in the irradiated regions. These results indicate that, among the tested materials, TG-Green is the best candidate for the i-HIBP detector.This work received funding from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No. 805162). G. Birkenmeier acknowledges funding from the Helmholtz Association under grant no. VHNG-1350. J. Galdon-Quiroga acknowledges funding from the Spanish Ministry of Science and Innovation under grant no. FJC2019-041092-I

Deletion or inhibition of NOD1 favors plaque stability and attenuates atherothrombosis in advanced atherogenesis

Atherothrombosis, the main cause of acute coronary syndromes (ACS), is characterized by the rupture of the atherosclerotic plaque followed by the formation of thrombi. Fatal plaque rupture sites show large necrotic cores combined with high levels of inflammation and thin layers of collagen. Plaque necrosis due to the death of macrophages and smooth muscle cells (SMCs) remains critical in the process. To determine the contribution of the innate immunity receptor NOD1 to the stability of atherosclerotic plaque, Apoe-/- and Apoe-/- Nod1-/- atherosclerosis prone mice were placed on a high-fat diet for 16 weeks to assess post-mortem advanced atherosclerosis in the aortic sinus. The proliferation and apoptosis activity were analyzed, as well as the foam cell formation capacity in these lesions and in primary cultures of macrophages and vascular SMCs obtained from both groups of mice. Our results reinforce the preeminent role for NOD1 in human atherosclerosis. Advanced plaque analysis in the Apoe-/- atherosclerosis model suggests that NOD1 deficiency may decrease the risk of atherothrombosis by decreasing leukocyte infiltration and reducing macrophage apoptosis. Furthermore, Nod1-/- SMCs exhibit higher proliferation rates and decreased apoptotic activity, contributing to thicker fibrous caps with reduced content of pro-thrombotic collagen. These findings demonstrate a direct link between NOD1 and plaque vulnerability through effects on both macrophages and SMCs, suggesting promising insights for early detection of biomarkers for treating patients before ACS occurs.This work was supported by the Ministerio Economía, Industria y Competitividad/Agencia Estatal de Investigación (SAF2016-79490-R, RTI2018-094727-B-100, SAF2015-64767-R, SAF2016-75004-R, SAF2017-82436-R/RTC2017-6283-1, PID2019-108977RB-100), Centro de Investigación Biomédica en Red en Enfermedades Cardiovasculares (CB16/11/00405, CB16/11/00257, CB16/11/00222), Fundación Ramón Areces (CIUP18A3864), Consorcio de Investigación en Red de la Comunidad de Madrid, S2017/BMD-3686 and Fondo Europeo de Desarrollo Regional

Integrated management of yellow aphid (Melanaphis sacchari Zehntner) in sorghum (Sorghum bicolor L.) Moench in Guerrero, Mexico

Sorghum is cultivated in tropical and subtropical regions of the world and is an important cereal for Mexico. However, it is affected by different pests, especially the yellow aphid. The objective of the research was to evaluate the effectiveness of biological, botanical and chemical insecticides in reducing Melanaphis sacchari populations in sorghum plants under greenhouse conditions. Planting was conducted in a greenhouse, using the sorghum hybrid 945-M. Pests, diseases and weeds management were implemented. The incidence of the yellow aphid was induced artificially. A total of 13 treatments were applied. The following variables were assessed: the number of aphids per leaf, the biological effectiveness of the treatments, plant height, diameter of the plant stem, number of leaves, and the weight of fresh and dry plants. An analysis of variance was conducted for each variable under study, as along with a comparison of means using the Tukey method (α=0.05) and correlation analysis using the SAS® 9.4 software. The chemical, biological and organic insecticide that exhibited the greatest control of the yellow aphid (more than 95%) were: Toretto® (sulfoxaflor), PHC® Meta Tron® (M. anisopliae), Bio-Die® (Argemonin, Berberine, Ricinin and a-Terthienyl). Adequate management strategies are needed to avoid health problems in people, environmental contamination and resistance or multiple resistance

Web-GIS approach to preventive conservation of heritage buildings

The effective implementation of preventive conservation approaches demands the employment of standardized and robust tools able to integrate the data coming from multiple sources, inspection and diagnosis techniques, as well as to ensure the proper information transfer between expert and non-expert users. Aiming to make a step forward in the state of the art of current conservation approaches, a cutting edge Web-GIS technology resorting to the intuitiveness of 360° panoramas and 3D point clouds in combination with the Internet of Things is presented in this work, demonstrating how physical and digital worlds can be linked for proper documentation and management of cultural heritage. To validate such a pioneering approach, one of the most representative and complex heritage buildings of Spain is used as a case study: the General Historical Library of Salamanca.This work was financed by ERDF funds through the V Sudoe Interreg program within the framework of the HeritageCare project (Ref. SOE1/P5/P0258), by project Patrimonio 5.0 (SA075P17), by FEDER funds through the Competitive Factors Operational Program (COMPETE) and by the Foundation for Science and Technology (FCT) within the scope of projects POCI-01-0145-FEDER-007633. The authors would like to express their gratitude to the personnel from the General Historical Library of the University of Salamanca as well as to the Centre for Computer Graphics of the University of Minho for the web implementation of the platform

Cortical Reshaping and Functional Recovery Induced by Silk Fibroin Hydrogels-Encapsulated Stem Cells Implanted in Stroke Animals

The restitution of damaged circuitry and functional remodeling of peri-injured areas constitute two main mechanisms for sustaining recovery of the brain after stroke. In this study, a silk fibroin-based biomaterial efficiently supports the survival of intracerebrally implanted mesenchymal stem cells (mSCs) and increases functional outcomes over time in a model of cortical stroke that affects the forepaw sensory and motor representations. We show that the functional mechanisms underlying recovery are related to a substantial preservation of cortical tissue in the first days after mSCs-polymer implantation, followed by delayed cortical plasticity that involved a progressive functional disconnection between the forepaw sensory (FLs1) and caudal motor (cFLm1) representations and an emergent sensory activity in peri-lesional areas belonging to cFLm1. Our results provide evidence that mSCs integrated into silk fibroin hydrogels attenuate the cerebral damage after brain infarction inducing a delayed cortical plasticity in the peri-lesional tissue, this later a functional change described during spontaneous or training rehabilitation-induced recovery. This study shows that brain remapping and sustained recovery were experimentally favored using a stem cell-biomaterial-based approach

Conscientious Objection in Spanish Podiatrists Students: A Questionnaire Survey

[Abstract] Objective: To explore attitudes towards conscientious objections among podiatrists students in Spain. Methods: Podiatrists students at University of A Coruña, King Rey Juan Carlos University, University of Sevilla and Complutense University of Madrid were emailed a link to complete an anonymous online questionnaire, hosted by an online survey company. A total of 432 podiatrists students responded. Results: Nearly half of the students in this survey stated that they believed in the right of podiatrist to conscientiously object to any procedure. Demand for the right to conscientiously object is greater in Roman Catholic podiatrists students when compared with other groups of religious podiatrists students. Discussion: Examining patients and podiatric treatments continues to be controversy issues among podiatrists students and this may contribute to the looming crisis in podiatry services over next years. This project sheds some light on how future podiatrist view some of their ethical rights and obligations. Using empirical evidence, it reveals that conscientious objection is an issue in the Spain podiatrists student body today. These data could help anticipate problems that may arise when these podiatrists students qualify and practice podiatry in the community. Conclusion: Clearer guidance is needed for podiatrists students about the issue of conscientious objection at podiatry school.[Resumen] Objetivo: Explorar actitudes hacia la objeción de conciencia entre estudiantes de podología en España. Métodos: Se realizó un cuestionario anónimo online vía email a estudiantes de podología de la Universidad del Rey Juan Carlos de la Coruña, la Universidad de Sevilla y la Universidad Complutense de Madrid, organizado por una empresa de encuestas online. Respondieron un total de 432 estudiantes de podología. Resultados: Casi la mitad de los estudiantes afirmaron en la encuesta que creían en el derecho del podólogo a la objeción de conciencia en cualquier procedimiento. La exigencia del derecho a objeción de conciencia fue mayor en estudiantes de podología católicos que en otros grupos de otras religiones. Discusión: Examinar a pacientes y los tratamientos de podología continúan siendo temas controversiales entre los estudiantes de podología y esto puede que contribuya a la inminente crisis en servicios de pedicura en los próximos años. Este proyecto derrama algo de luz sobre como futuros podólogos ven algunos de sus derechos y obligaciones éticas. Usando evidencia científica, revela que la objeción de conciencia es un tema para los estudiantes de podología en España hoy día. Estos datos pueden ayudar a anticipar problemas que puedan surgir cuando estos estudiantes de podología califiquen y practiquen podología en la comunidad. Conclusión: Se necesitan pautas más claras para estudiantes de podología sobre el tema de objeción de conciencia en la Escuela de Podología.[Resumo] Objetivo: Explorar atitudes com relação à objeção de consciência entre os estudantes de podologia na Espanha. Método: Aos estudantes de podologia da Universidade Universidade Rei Juan Carlos, de Corunha, da Universidade de Sevilla e da Universidade Complutense de Madri foram enviados por email um link para completar um questionário online anônimo, hospedado por uma empresa de pesquisa on-line. Um total de 432 alunos de podologia responderam. Resultados: Quase metade dos alunos nesta pesquisa afirmaram que acreditavam no direito de podólogo se opor conscientemente a qualquer procedimento. A demanda para o direito de se opor conscientemente é maior em estudantes católicos romanos, quando comparado com outros grupos religiosos de estudantes. Discussão: O exame de pacientes e tratamentos podiátricos continuam a ser problema de controvérsia entre os alunos de podologia e isso pode contribuir para a crise iminente nos serviços de podologia para os próximos anos. Este projeto lança alguma luz sobre a forma de o futuro podólogo conhecer alguns dos seus direitos e obrigações éticas. Usando a evidência empírica, revela que a objeção de consciência é um problema no corpo discente de podologia da Espanha, hoje. Estes dados poderiam ajudar a antecipar problemas que podem surgir quando esses estudantes de podología se qualificarem e praticarem a podologia na comunidade. Conclusão: Orientação mais esclarecida é necessária para alunos de podologia sobre a questão da objeção de consciência no curso de graduação

Optomechanical devides for mechanobiological fingerprinting

Resumen del trabajo presentado en el Frontiers of Nanomechanical Systems (FSN2021), celebraod de forma virtual del 19 al 21 de enero de 2021Twenty years have passed since the first detection of biomolecular recognition using micromechanical systems[1]. In the last two decades, micro- nanomechanical systems have been refined to achieve amazing detection limits in force and mass that have enabled different schemes for ultrasensitive measurements of biological interactions as well as new ways of biological spectrometry. More recently, these figures of merit have been improved by coupling optical cavities to mechanical systems. In this talk, I will review the use of micro- nanomechanical systems for mechanobiological fingerprinting of biological entities, particularizing in the contributions of our group [2]. An essential core of this topic is the discussion about the mechanical coupling between a biological particle and a mechanical resonator, an issue that it is has been often oversimplified. We show that the biomechanical coupling that emerges between a bioparticle and a mechanical resonator is more complex than previously expect and it can give rise to different interaction regimes, in which the resonator response is dominated by different physical parameters of the analyte [3-4]. In particular, we will show experiments done with a variety of micro- nano- optomechanical systems using different measurement schemes where the mass, the stiffness and even the vibration modes of single biological entities can be measured with high sensitivity. It is now widely appreciated the essential role of mechanics in relevant biological processes and how disease can be revealed as changes in the mechanical properties of biological matter. I am pretty sure that future developments in optomechanical devices will contribute for major understanding of diseases as well as for new avenues in diagnosis and therapy