18 research outputs found

    Luminescent acetylthiol derivative tripodal osmium(II) and iridium(III) complexes: Spectroscopy in solution and on surfaces

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    Luminescent Os(II) and Ir(III) complexes containing a tripodal-type structure terminalized with three thiol derivatives are described. The tripod is introduced through derivatization, with a rigid spacer, of a phenanthroline ligand coordinated to the metal ion, and the entire structure possesses axial geometry. The geometry of the complexes combined with the three anchoring sites, the thiol groups, allows the complexes to adopt an almost perpendicular arrangement to the surfaces and the formation of a well-packed monolayer on Au substrates. The photophysical and electrochemical behavior of the complexes is studied in solution and on surfaces. Furthermore, a self-assembled monolayer (SAM) of Os(II) complexes on an ultraflat Au surface is used to fabricate a metal-molecule-metal junction with Au and In Ga eutectic as electrodes. The Os(II) SAM in the tunneling junction exhibits rectification behavior which is opposite in direction to that which we have previously shown for Ru(II) SAM

    The German National Registry of Primary Immunodeficiencies (2012-2017)

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    Introduction: The German PID-NET registry was founded in 2009, serving as the first national registry of patients with primary immunodeficiencies (PID) in Germany. It is part of the European Society for Immunodeficiencies (ESID) registry. The primary purpose of the registry is to gather data on the epidemiology, diagnostic delay, diagnosis, and treatment of PIDs. Methods: Clinical and laboratory data was collected from 2,453 patients from 36 German PID centres in an online registry. Data was analysed with the software Stata® and Excel. Results: The minimum prevalence of PID in Germany is 2.72 per 100,000 inhabitants. Among patients aged 1–25, there was a clear predominance of males. The median age of living patients ranged between 7 and 40 years, depending on the respective PID. Predominantly antibody disorders were the most prevalent group with 57% of all 2,453 PID patients (including 728 CVID patients). A gene defect was identified in 36% of patients. Familial cases were observed in 21% of patients. The age of onset for presenting symptoms ranged from birth to late adulthood (range 0–88 years). Presenting symptoms comprised infections (74%) and immune dysregulation (22%). Ninety-three patients were diagnosed without prior clinical symptoms. Regarding the general and clinical diagnostic delay, no PID had undergone a slight decrease within the last decade. However, both, SCID and hyper IgE- syndrome showed a substantial improvement in shortening the time between onset of symptoms and genetic diagnosis. Regarding treatment, 49% of all patients received immunoglobulin G (IgG) substitution (70%—subcutaneous; 29%—intravenous; 1%—unknown). Three-hundred patients underwent at least one hematopoietic stem cell transplantation (HSCT). Five patients had gene therapy. Conclusion: The German PID-NET registry is a precious tool for physicians, researchers, the pharmaceutical industry, politicians, and ultimately the patients, for whom the outcomes will eventually lead to a more timely diagnosis and better treatment

    Identification of regulatory variants associated with genetic susceptibility to meningococcal disease.

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    Non-coding genetic variants play an important role in driving susceptibility to complex diseases but their characterization remains challenging. Here, we employed a novel approach to interrogate the genetic risk of such polymorphisms in a more systematic way by targeting specific regulatory regions relevant for the phenotype studied. We applied this method to meningococcal disease susceptibility, using the DNA binding pattern of RELA - a NF-kB subunit, master regulator of the response to infection - under bacterial stimuli in nasopharyngeal epithelial cells. We designed a custom panel to cover these RELA binding sites and used it for targeted sequencing in cases and controls. Variant calling and association analysis were performed followed by validation of candidate polymorphisms by genotyping in three independent cohorts. We identified two new polymorphisms, rs4823231 and rs11913168, showing signs of association with meningococcal disease susceptibility. In addition, using our genomic data as well as publicly available resources, we found evidences for these SNPs to have potential regulatory effects on ATXN10 and LIF genes respectively. The variants and related candidate genes are relevant for infectious diseases and may have important contribution for meningococcal disease pathology. Finally, we described a novel genetic association approach that could be applied to other phenotypes

    Photofunctional surfaces for quantitative fluorescence microscopy: monitoring the effects of photogenerated reactive oxygen species at single cell level with spatiotemporal resolution

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    Herein, we report on the implementation of photofunctional surfaces for the investigation of cellular responses by means of quantitative fluorescence microscopy. The developed substrates are able to produce reactive oxygen species under the fluorescence microscope upon irradiation with visible light, and the behavior of cells grown on these surfaces can be consequently investigated in situ and in real time. Moreover, a suitable methodology is presented to simultaneously monitor phototriggered morphological changes and the associated molecular pathways with spatiotemporal resolution employing time-resolved fluorescence anisotropy at the single cell level. The results showed that morphological changes can be complemented with a quantitative evaluation of the associated molecular signaling cascades for the unambiguous assignment of reactive oxygen species-related photoinduced apoptosis. Indeed, similar phenotypes are associated with different cellular processes. Our methodology facilitates the in vitro design and evaluation of photosensitizers for the treatment of cancer and infectious diseases with the aid of functional fluorescence microscopy.Fil: Stegemann, Linda. Westfalische Wilhelms Universitat; AlemaniaFil: Schuermann, Klaus C.. Institut Max Planck Fur Molekulare Physiologie; AlemaniaFil: Strassert, Cristian A.. Westfalische Wilhelms Universitat; AlemaniaFil: Grecco, Hernan Edgardo. Institut Max Planck Fur Molekulare Physiologie; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentin

    Controllable Growth and Field-Effect Property of Monolayer to Multilayer Microstripes of an Organic Semiconductor

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    The controllable growth of partially aligned monolayer to multilayer micrometer stripes was demonstrated by adjusting the pulling speed in a dip-coating process. The number of molecular layers decreases with the increasing pulling speed. A lower pulling speed yields mixed multilayers (3−9 monolayers). It is noteworthy that pure monolayer and bilayer microstripes over large areas can be obtained at high pulling speeds. The stripe morphology strongly depends on the pulling speed or the number of molecular layers. XRD and confocal fluorescence measurements manifest that monolayer stripes are amorphous, while multilayer stripes (≥2) consist of crystalline states. FET devices were fabricated on these stripes. Monolayer stripes failed to reveal a field effect due to their amorphous state. In contrast, multilayer stripes exhibit good field-effect behavior. This study provides useful information for future molecular design in controlling molecular architectures. The controllable growth from monolayer to multilayer offers a powerful experimental system for fundamental research into the real charge accumulation and transporting layers for OFETs

    Co-imaging extrinsic, intrinsic and effector caspase activity by fluorescence anisotropy microscopy

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    In order to overcome intercellular variability and thereby effectively assess signal propagation in biological networks it is imperative to simultaneously quantify multiple biological observables in single living cells. While fluorescent biosensors have been the tool of choice to monitor the dynamics of protein interaction and enzymatic activity, co-measuring more than two of them has proven challenging. In this work, we designed three spectrally separated anisotropy-based Förster Resonant Energy Transfer (FRET) biosensors to overcome this difficulty. We demonstrate this principle by monitoring the activation of extrinsic, intrinsic and effector caspases upon apoptotic stimulus. Together with modelling and simulations we show that time of maximum activity for each caspase can be derived from the anisotropy of the corresponding biosensor. Such measurements correlate relative activation times and refine existing models of biological signalling networks, providing valuable insight into signal propagation. Keywords: Caspase activity, Apoptotic network, Anisotropy FRET biosensor, Co-monitoring, Imaging, Polarization microscop

    Semiconductive, one-dimensional, self-assembled nanostructures based on oligopeptides with π-conjugated segments

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    π Stacking between the β sheets: A newly designed π-conjugated peptide can be assembled into a one-dimensional nanostructure with strong π–π intermolecular electronic communication. A nanoelectronic device based on the achieved individual nanostructure was used to measure conductivity
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