Imaging the Near Field of Dielectric and Metallic Nanoparticles

Trabajo presentado en el 7th International Conference on Photo-Excited Processes and Applications , celebrado en Copenhague (Dinamarca), del 15 al 20 de agosto de 201

Novel desmoplakin mutation: juvenile biventricular cardiomyopathy with left ventricular non-compaction and acantholytic palmoplantar keratoderma

Two sons of a consanguineous marriage developed biventricular cardiomyopathy. One boy died of severe heart failure at the age of 6 years, the other was transplanted because of severe heart failure at the age of 10 years. In addition, focal palmoplantar keratoderma and woolly hair were apparent in both boys. As similar phenotypes have been described in Naxos disease and Carvajal syndrome, respectively, the genes for plakoglobin (JUP) and desmoplakin (DSP) were screened for mutations using direct genomic sequencing. A novel homozygous 2 bp deletion was identified in an alternatively spliced region of DSP. The deletion 5208_5209delAG led to a frameshift downstream of amino acid 1,736 with a premature truncation of the predominant cardiac isoform DSP-1. This novel homozygous truncating mutation in the isoform-1 specific region of the DSP C-terminus caused Carvajal syndrome comprising severe early-onset heart failure with features of non-compaction cardiomyopathy, woolly hair and an acantholytic form of palmoplantar keratoderma in our patient. Congenital hair abnormality and manifestation of the cutaneous phenotype in toddler age can help to identify children at risk for cardiac death

Antenna-assisted picosecond control of nanoscale phase transition in vanadium dioxide

Nanoscale devices in which the interaction with light can be configured using external control signals hold great interest for next-generation optoelectronic circuits. Materials exhibiting a structural or electronic phase transition offer a large modulation contrast with multi-level optical switching and memory functionalities. In addition, plasmonic nanoantennas can provide an efficient enhancement mechanism for both the optically induced excitation and the readout of materials strategically positioned in their local environment. Here, we demonstrate picosecond all-optical switching of the local phase transition in plasmonic antenna-vanadium dioxide (VO2) hybrids, exploiting strong resonant field enhancement and selective optical pumping in plasmonic hotspots. Polarization- and wavelength-dependent pump-probe spectroscopy of multifrequency crossed antenna arrays shows that nanoscale optical switching in plasmonic hotspots does not affect neighboring antennas placed within 100 nm of the excited antennas. The antenna-assisted pumping mechanism is confirmed by numerical model calculations of the resonant, antenna-mediated local heating on a picosecond time scale. The hybrid, nanoscale excitation mechanism results in 20 times reduced switching energies and 5 times faster recovery times than a VO2 film without antennas, enabling fully reversible switching at over two million cycles per second and at local switching energies in the picojoule range. The hybrid solution of antennas and VO2 provides a conceptual framework to merge the field localization and phase-transition response, enabling precise, nanoscale optical memory functionalities

Quantitative imaging of the optical near field

When exposing small particles on a substrate to a light plane wave, the scattered optical near field is spatially modulated and highly complex. We show, for the particular case of dielectric microspheres, that it is possible to image these optical near-field distributions in a quantitative way. By placing a single microsphere on a thin film of the photosensitive phase change material Ge2Sb5Te5 and exposing it to a single short laser pulse, the spatial intensity modulation of the near field is imprinted into the film as a pattern of different material phases. The resulting patterns are investigated by using optical as well as high-resolution scanning electron microscopy. Quantitative information on the local optical near field at each location is obtained by calibrating the material response to pulsed laser irradiation. We discuss the influence of polarization and angle of incidence of the laser beam as well as particle size on the field distribution. The experimental results are in good quantitative agreement with a model based on a rigorous solution of Maxwell's equations. Our results have potential application to near-field optical lithography and experimental determination of near fields in complex nanostructures. © 2012 Optical Society of America.We also acknowledge partial funding from Spanish National Research Projects (Grants No. TEC2011-22422 and TEC2008-01183, MAT2010-14885, and Consolider NanoLight.es) and by Deutsche Forschungsgemeinschaft (SFB 767 and SPP1327).Peer Reviewe

Understanding 'Euthanasia' Across Various Medical Practices

End-of-life decisions and assisted suicide аге often equated with 'euthanasia.' In everyday parlance of social actors, the term euthanasia is understood rather broadly, even lumped together with other medical procedures. Still, the рареr argues that 'intended merciful death,' whether we like the definition or not, ought not to bе equated with other practices. Although all of these medical procedures result in the destruction of potential or actual life, the reasons behind such actions could bе quite different from empathy ог mercy, making the acceptance and advocacy of а problematic definition and understanding of euthanasia the subject of ethical and social debates and analyses. When considering the Universal Declaration on Bioethics and Human Rights, the debate stretches out to include also vulnerable groups in general, which in the contemporary context range from homeless persons and other marginalized groups to embryos created during IVF (in vitro fertilization). The paper presents two case studies, chosen from ten personal stories of former and cuпent IVF procedure patients . In all ten narratives, interlocutors equate abortion with embryo reduction, and both of those with euthanasia. The paper analyzes their perspective to embryos that were not implanted, as well as similarities and differences in their views regarding the activities in the cases of implanted embryos (twin and triplet pregnancies)

Altered cortical and subcortical connectivity due to infrasound administered near the hearing threshold: Evidence from fMRI

In the present study, the brain's response towards near- and supra-threshold infrasound (IS) stimulation (sound frequency near-threshold) as well as the right superior frontal gyrus (rSFG) during the near-threshold condition. In summary, this study is the first to demonstrate that infrasound near the hearing threshold may induce changes of neural activity across several brain regions, some of which are known to be involved in auditory processing, while others are regarded as keyplayers in emotional and autonomic control. These findings thus allow us to speculate on how continuous exposure to (sub-)liminal IS could exert a pathogenic influence on the organism, yet further (especially longitudinal) studies are required in order to substantialize these findings