Scattering cancellation of the magnetic dipole field from macroscopic spheres

Based on the scattering cancellation technique we suggest a cloak that allows to conceal macroscopic objects, i.e. objects with an optical size comparable to wavelengths in the visible and whose scattering response is dominated by a magnetic dipole contribution. The key idea in our approach is to use a shell of polaritonic spheres around the object to be cloaked. These spheres exhibit an artificial magnetism. In a systematic investigation, where we progressively increase the complexity of the considered structure, we devise the requirements imposed on the shell and outline how it can be implemented with natural available materials

Gouy phase anomaly in photonic nanojets

We investigate in real space amplitude and phase distributions of light in photonic nanojets emerging from micrometer-sized dielectric spheres with a high-resolution interference microscope. Strong localization of light and a Gouy phase anomaly are witnessed. We show that the phase advance of photonic nanojets significantly deviates from a plane wave due to the sudden transition from a converging to a diverging wave front. Understanding such phase anomalies and verifying the presence of photonic nanojets promises to pave the way to prospective applications that may exploit the ability to localize light in spatial domains smaller than the usual resolution limit

Degeneracija aksona i esteraza povezana s neuropatskim djelovanjem organofosfornih spojeva - pregled

This brief review summarises recent observations which suggest a possible mechanism for organophosphateinduced delayed neuropathy (OPIDN). Neuropathy target esterase (NTE) has been shown to deacylate endoplasmic reticulum (ER) membrane phosphatidylcholine (PtdCho). Raised levels of PtdCho are present in the brains of swiss cheese/NTE mutant Drosophila together with abnormal membrane structures, axonal and dendritic degeneration and neural cell loss. Similar vacuolated pathology is found in the brains of mice with brain-specific deletion of the NTE gene and, in old age, these mice show clinical and histopathological features of neuropathy resembling those in wild-type mice chronically dosed with tri-ortho-cresylphosphate. It is suggested that OPIDN results from the loss of NTE’s phospholipase activity which in turn causes ER malfunction and perturbation of axonal transport and glial-axonal interactions.Ovim se kratkim pregledom razmatraju nedavna opažanja koja upućuju na mogući mehanizam odgođene neuropatije uzrokovane organofosfatima (engl. organophosphate-induced delayed neuropathy, krat. OPIDN). Za esterazu povezanu s neuropatskim djelovanjem organofosfornih spojeva (engl. neuropathy target esterase, krat. NTE) dokazano je da deacilira fosfatidilkolin (PtdCho) membrane endoplazmatskog retikuluma (ER). Povišene razine PtdCho prisutne su u mozgu swiss cheese/NTE mutanta mušice Drosophila uz abnormalne membranske strukture, degeneraciju aksona i dendrita te gubitak neurona. Slična je vakuolarna patologija zamijećena u mozgu miševa u kojih je obrisan NTE gen u mozgu te koji u starijoj dobi pokazuju kliničke i histopatološke znakove neuropatije koja je slična onoj u običnih miševa kronično tretiranih tri-ortho-krezilfosfatom. Odgođena neuropatija uzrokovana organofosfatima mogla bi biti posljedicom prestanka djelovanja fosfolipaze NTE, što potom uzrokuje zatajenje endoplazmatskog retikuluma i smetnje u prijenosu signala putem aksona te interakcije između glija i aksona

Large-scale analysis of Drosophila core promoter function using synthetic promoters

The core promoter plays a central role in setting metazoan gene expression levels, but how exactly it “computes” expression remains poorly understood. To dissect its function, we carried out a comprehensive structure–function analysis in Drosophila. First, we performed a genome-wide bioinformatic analysis, providing an improved picture of the sequence motifs architecture. We then measured synthetic promoters’ activities of ~3,000 mutational variants with and without an external stimulus (hormonal activation), at large scale and with high accuracy using robotics and a dual luciferase reporter assay. We observed a strong impact on activity of the different types of mutations, including knockout of individual sequence motifs and motif combinations, variations of motif strength, nucleosome positioning, and flanking sequences. A linear combination of the individual motif features largely accounts for the combinatorial effects on core promoter activity. These findings shed new light on the quantitative assessment of gene expression in metazoans

Refraction limit of miniaturized optical systems: A ball-lens example

We study experimentally and theoretically the electromagnetic field in amplitude and phase behind ball-lenses across a wide range of diameters, ranging from a millimeter scale down to a micrometer. Based on the observation, we study the transition between the refraction and diffraction regime. The former regime is dominated by observables for which it is sufficient to use a ray-optical picture for an explanation, e.g., a cusp catastrophe and caustics. A wave-optical picture, i.e. Mie theory, is required to explain the features, e.g., photonic nanojets, in the latter regime. The vanishing of the cusp catastrophe and the emergence of the photonic nanojet is here understood as the refraction limit. Three different criteria are used to identify the limit: focal length, spot size, and amount of cross-polarization generated in the scattering process. We identify at a wavelength of 642 nm and while considering ordinary glass as the ball-lens material, a diameter of approximately 10 µm as the refraction limit. With our study, we shed new light on the means necessary to describe micro-optical system. This is useful when designing optical devices for imaging or illumination

A Structured, Manual-Based Low-Level Intervention vs. Treatment as Usual Evaluated in a Randomized Controlled Trial for Adolescents with Extreme Obesity - the STEREO Trial

Background: To compare efficacy and safety of a manual-based low-level psychological intervention with treatment as usual (weight loss treatment). Methods: A two-armed randomized controlled trial without blinding and computer-based stratified block randomization included adolescents and young adults (14.0-24.9 years) with a BMI ≥ 30 kg/m2 at five German university hospitals. Primary outcomes were adherence (participation rate ≥ 5/6 sessions) and quality of life (DISABKIDS-37) 6 months after randomization. Secondary outcomes included depression, self-esteem, and perceived stress scores. Results: Of 397 screened adolescents, 119 (mean BMI 40.4 ± 7.0 kg/m2, 49.6% female) were randomized to the manual-based low-level intervention (n = 59) or treatment as usual (n = 60). We observed no group difference for adherence (absolute risk reduction 0.4%, 95% CI -14.7% to 15.5%; p = 1.0) or health- related quality of life (score difference 8.1, 95% CI -2.1 to 18.3; p = 0.11). Among all secondary outcomes, we detected explorative evidence for an effect on the DISABKIDS-37 ‘social exclusion' subscale (score difference 15.5; 95% CI 1.6-29.4; p = 0.03). 18/19 adverse events occurred in 26 participants, none were classified as serious. Conclusion: Adherence to a coping-oriented intervention was comparable to weight loss treatment, although it was weak in both interventions. Psychological interventions may help to overcome social isolation; further confirmation is required

A data set from flash X-ray imaging of carboxysomes

Citation: Hantke, M. F., Hasse, D., Ekeberg, T., John, K., Svenda, M., Loh, D., . . . Maia, F. R. N. C. (2016). A data set from flash X-ray imaging of carboxysomes. Scientific Data, 3. doi:10.1038/sdata.2016.61Ultra-intense femtosecond X-ray pulses from X-ray lasers permit structural studies on single particles and biomolecules without crystals. We present a large data set on inherently heterogeneous, polyhedral carboxysome particles. Carboxysomes are cell organelles that vary in size and facilitate up to 40% of Earth's carbon fixation by cyanobacteria and certain proteobacteria. Variation in size hinders crystallization. Carboxysomes appear icosahedral in the electron microscope. A protein shell encapsulates a large number of Rubisco molecules in paracrystalline arrays inside the organelle. We used carboxysomes with a mean diameter of 115±26 nm from Halothiobacillus neapolitanus. A new aerosol sample-injector allowed us to record 70,000 low-noise diffraction patterns in 12 min. Every diffraction pattern is a unique structure measurement and high-throughput imaging allows sampling the space of structural variability. The different structures can be separated and phased directly from the diffraction data and open a way for accurate, high-throughput studies on structures and structural heterogeneity in biology and elsewhere

Accumulation of α-synuclein mediates podocyte injury in Fabry nephropathy

Current therapies for Fabry disease are based on reversing intracellular accumulation of globotriaosylceramide (Gb3) by enzyme replacement therapy (ERT) or chaperone-mediated stabilization of the defective enzyme, thereby alleviating lysosomal dysfunction. However, their effect in the reversal of end-organ damage, like kidney injury and chronic kidney disease, remains unclear. In this study, ultrastructural analysis of serial human kidney biopsies showed that long-term use of ERT reduced Gb3 accumulation in podocytes but did not reverse podocyte injury. Then, a CRISPR/Cas9–mediated α-galactosidase knockout podocyte cell line confirmed ERT-mediated reversal of Gb3 accumulation without resolution of lysosomal dysfunction. Transcriptome-based connectivity mapping and SILAC-based quantitative proteomics identified α-synuclein (SNCA) accumulation as a key event mediating podocyte injury. Genetic and pharmacological inhibition of SNCA improved lysosomal structure and function in Fabry podocytes, exceeding the benefits of ERT. Together, this work reconceptualizes Fabry-associated cell injury beyond Gb3 accumulation, and introduces SNCA modulation as a potential intervention, especially for patients with Fabry nephropathy.publishedVersio

Outcome measures in chronic obstructive pulmonary disease (COPD): strengths and limitations

Current methods for assessing clinical outcomes in COPD mainly rely on physiological tests combined with the use of questionnaires. The present review considers commonly used outcome measures such as lung function, health status, exercise capacity and physical activity, dyspnoea, exacerbations, the multi-dimensional BODE score, and mortality. Based on current published data, we provide a concise overview of the principles, strengths and weaknesses, and discuss open questions related to each methodology. Reviewed is the current set of markers for measuring clinically relevant outcomes with particular emphasis on their limitations and opportunities that should be recognized when assessing and interpreting their use in clinical trials of COPD