59 research outputs found
Untersuchungen zur CO2-Methanisierung mittels Fe-Ni-Hydrotalcit-basierter Katalysatoren
Die langfristige Speicherung von ĂŒberschĂŒssiger Energie aus regenerativen Quellen ist ein ungelöstes Problem der Energiewende. Ein Ansatz zur Lösung dieses Problems bietet das Power-to-Gas-Konzept, bei dem Methan aus Wasserstoff und Kohlenstoffdioxid als Ersatz fĂŒr Erdgas erzeugt wird. Da diese Reaktion kinetisch limitiert ist, ist die Verwendung eines geeigneten heterogenen Katalysators erforderlich. Aufgrund ihrer hohen AktivitĂ€t und ihres niedrigen Preises werden hĂ€ufig nickelhaltige Katalysatoren eingesetzt. In der vorliegenden Arbeit wurde die Eignung von Fe-Ni-Hydrotalcit-basierten Katalysatoren fĂŒr dieses Konzept untersucht, wobei der Schwerpunkt auf der Bestimmung der AbhĂ€ngigkeit der katalytischen AktivitĂ€t vom Eisengehalt lag. Dabei zeigte sich, dass geringe Mengen an Eisen die Methanausbeute verbessern. Eine ErklĂ€rung fĂŒr diese AktivitĂ€tssteigerung liefern die Ergebnisse von in-situ-DRIFTS-Untersuchungen an eisenhaltigen und eisenfreien Ni-Hydrotalcit-Katalysatoren
First Case of Automatic His Potential Detection With a Novel Ultra High-density Electroanatomical Mapping System for AV Nodal Ablation
AbstractA 74-year old was considered for atrioventricular (AV) nodal ablation in view of atrial fibrillation (AF) with poorly controlled ventricular rate despite being on amiodarone. Targeted AV nodal ablation was successfully performed after identifying the target site for ablation by reviewing an ultra high-density map of the His region produced by automatic electrogram annotation
Optimal timing of contrast-enhanced three-dimensional magnetic resonance left atrial angiography before pulmonary vein ablation
Background: To achieve high image quality of cardiovascular magnetic resonance (CMR) pulmonary vein (PV) angiography prior catheter ablation in patients with atrial fibrillation, optimal timing of the angiographic sequence during contrast agent passage is important. The present study identified influential cardiovascular parameters for prediction of contrast agent travel time.Methods: One hundred six consecutive patients underwent a CMR examination including three-dimensional (3D) contrast-enhanced PV angiography with real-time bolus tracking prior to catheter ablation. Correct scan timing was characterized by relative signal enhancement measurements in the pulmonary artery, left atrium (LA), and ascending aorta. Furthermore, left- and right-ventricular function, left- and right-atrial dimensions, presence of mitral or tricuspid insufficiencies, and main pulmonary artery diameter were determined.Results: The highest relative signal enhancement in LA demonstrated optimal scan timing. Contrast agent travel time showed wide variability (range: 12â42 s; mean: 18 ± 4 s). On univariate analysis, most cardiovascular parameters correlated with contrast agent travel time while on multivariate analysis left- and right-ventricular function remained the only independent predictors, but overall a poor fit to the data (adjusted R2, 27.5%) was found.Conclusions: Contrast agent travel time was mainly influenced by left- and right-ventricular function but prediction models poorly fitted the data. Thus, 3D PV angiography prior to PV ablation procedures necessitates real-time assessment, with visual determination of individual contrast agent passage time to ensure consistently high CMR image quality
Toward Sharing Brain Images: Differentially Private TOF-MRA Images With Segmentation Labels Using Generative Adversarial Networks
Sharing labeled data is crucial to acquire large datasets for various Deep Learning applications. In medical imaging, this is often not feasible due to privacy regulations. Whereas anonymization would be a solution, standard techniques have been shown to be partially reversible. Here, synthetic data using a Generative Adversarial Network (GAN) with differential privacy guarantees could be a solution to ensure the patient's privacy while maintaining the predictive properties of the data. In this study, we implemented a Wasserstein GAN (WGAN) with and without differential privacy guarantees to generate privacy-preserving labeled Time-of-Flight Magnetic Resonance Angiography (TOF-MRA) image patches for brain vessel segmentation. The synthesized image-label pairs were used to train a U-net which was evaluated in terms of the segmentation performance on real patient images from two different datasets. Additionally, the FrĂ©chet Inception Distance (FID) was calculated between the generated images and the real images to assess their similarity. During the evaluation using the U-Net and the FID, we explored the effect of different levels of privacy which was represented by the parameter Ï”. With stricter privacy guarantees, the segmentation performance and the similarity to the real patient images in terms of FID decreased. Our best segmentation model, trained on synthetic and private data, achieved a Dice Similarity Coefficient (DSC) of 0.75 for Ï” = 7.4 compared to 0.84 for Ï” = â in a brain vessel segmentation paradigm (DSC of 0.69 and 0.88 on the second test set, respectively). We identified a threshold of Ï” <5 for which the performance (DSC <0.61) became unstable and not usable. Our synthesized labeled TOF-MRA images with strict privacy guarantees retained predictive properties necessary for segmenting the brain vessels. Although further research is warranted regarding generalizability to other imaging modalities and performance improvement, our results mark an encouraging first step for privacy-preserving data sharing in medical imaging
The Human Centriolar Protein CEP135 Contains a Two-Stranded Coiled-Coil Domain Critical for Microtubule Binding
Centrioles are microtubule-based structures that play important roles notably in cell division and cilium biogenesis. CEP135/Bld10p family members are evolutionarily conserved microtubule-binding proteins important for centriole formation. Here, we analyzed in detail the microtubule-binding activity of human CEP135 (HsCEP135). X-ray crystallography and small-angle X-ray scattering in combination with molecular modeling revealed that the 158 N-terminal residues of HsCEP135 (HsCEP135-N) form a parallel two-stranded coiled-coil structure. Biochemical, cryo-electron, and fluorescence microscopy analyses revealed that in vitro HsCEP135-N interacts with tubulin, protofilaments, and microtubules and induces the formation of microtubule bundles. We further identified a 13 amino acid segment spanning residues 96-108, which represents a major microtubule-binding site in HsCEP135-N. Within this segment, we identified a cluster of three lysine residues that contribute to the microtubule bundling activity of HsCEP135-N. Our results provide the first structural information on CEP135/Bld10p proteins and offer insights into their microtubule-binding mechanism
BioeconomĂa del Norte Argentino: situaciĂłn actual, potencialidades y futuros posibles. Documento de trabajo
El Proyecto: âBioeconomĂa argentina: Construyendo un futuro inteligente y sustentable para el Norte argentino 2030â, ha sido ejecutado a partir de junio 2018 por el Consorcio que integra el Instituto Nacional de TecnologĂa Agropecuaria (INTA), el Instituto Nacional de TecnologĂa Industrial (INTI), la Universidad Nacional del Nordeste (UNNE), la Universidad Nacional de Salta (unas) y la Universidad Nacional de Santiago del Estero (UNSE). El proyecto surge de la convocatoria emitida en mayo de 2017 por el Ministerio de Ciencia, TecnologĂa e InnovaciĂłn Productiva - MINCyT, contando con el financiamiento del Banco Mundial (PrĂ©stamo BIRF N° 8634/AR).El estudio se planteĂł como principal objetivo el desarrollo de un diagnĂłstico y ejercicio de prospectiva sobre la BioeconomĂa del Norte argentino, identificando tendencias, futuros posibles y ĂĄreas de intervenciĂłn del gobierno nacional y territorial en el ĂĄmbito de la ciencia, tecnologĂa e innovaciĂłn (CTI). La esencia de este emprendimiento parte de pensar la bioeconomĂa dentro de una estrategia de bioindustrializaciĂłn, como un instrumento central para el desarrollo regional de la Argentina, enmarcado en un proyecto nacional comprometido con la cohesiĂłn social y territorial.
En esta publicaciĂłn se documenta el trabajo realizado por el proyecto con el propĂłsito de plantear la situaciĂłn actual, potencialidades y futuros posibles de la bioeconomĂa del Norte argentino. Se espera que sirva para difundir y vigorizar la importancia institucional de la bioeconomĂa como instrumento estratĂ©gico del desarrollo regional y territorial. Se pretende, a su vez, movilizar el ĂĄmbito polĂtico-institucional con el propĂłsito de acordar la imagen del futuro deseable y la estrategia para alcanzarlo, estableciendo una agenda de I+D+i y plan de acciĂłn. Estos instrumentos deberĂan contribuir a impulsar el desarrollo de la industrializaciĂłn biolĂłgica en el Norte argentino como parte central de la polĂtica industrial. Al mismo tiempo, darĂa lugar a impulsar el fortalecimiento de una plataforma interinstitucional e interdisciplinaria que sustente las polĂticas pĂșblicas, el sistema de gobernanza y los marcos regulatorios que promuevan el desarrollo de la bioeconomĂa regional.CIEPFil: Bocchetto, Roberto Mario. Instituto Nacional de TecnologĂa Agropecuaria (INTA); ArgentinaFil: Gauna, Diego HernĂĄn. Instituto Nacional de TecnologĂa Agropecuaria (INTA). Centro de InvestigaciĂłn en EconomĂa y Prospectiva (CIEP); ArgentinaFil: Gonzalez, Claudia Beatriz. Instituto Nacional de TecnologĂa Agropecuaria (INTA). Instituto de TecnologĂa de Alimentos; ArgentinaFil: Bravo, Gonzalo Carlos. Instituto Nacional de TecnologĂa Agropecuaria (INTA). EstaciĂłn Experimental Agropecuaria Salta; ArgentinaFil: Rearte, MartĂn. Instituto Nacional de TecnologĂa Industrial (INTI); ArgentinaFil: Molina Tirado, Liliana. Instituto Nacional de TecnologĂa Industrial (INTI); ArgentinaFil: Hilbert, Jorge Antonio. Instituto Nacional de TecnologĂa Agropecuaria (INTA). Instituto de IngenierĂa Rural; ArgentinaFil: Eisenberg, Patricia. Instituto Nacional de TecnologĂa Industrial (INTI); ArgentinaFil: Lecuona, Roberto Eduardo. Instituto Nacional de TecnologĂa Agropecuaria (INTA). Instituto de MicrobiologĂa y ZoologĂa AgrĂcola; ArgentinaFil: Taraborrelli, Diego Sebastian. . Instituto Nacional de TecnologĂa Agropecuaria (INTA). Centro de InvestigaciĂłn en EconomĂa y Prospectiva (CIEP); ArgentinaFil: Papagno, Silvina Graciela. Instituto Nacional de TecnologĂa Agropecuaria (INTA); ArgentinaFil: Vaudagna, Sergio Ramon. Instituto Nacional de TecnologĂa Agropecuaria (INTA). Instituto TecnologĂa de Alimentos; Argentina
Recovery index, attentiveness and state of memory after xenon or isoflurane anaesthesia: a randomized controlled trial
<p>Abstract</p> <p>Background</p> <p>Performance of patients immediately after anaesthesia is an area of special interest and so a clinical trial was conducted to compare Xenon with Isoflurane anaesthesia. In order to assess the early cognitive recovery the syndrome short test (SST) according to Erzigkeit (Geromed GmbH) was applied.</p> <p>Methods</p> <p>ASA I and II patients undergoing long and short surgical interventions were randomised to receive either general anaesthesia with Xenon or Isoflurane. The primary endpoint was the validated SST which covering memory disturbances and attentiveness. The test was used on the day prior to intervention, one and three hours post extubation. The secondary endpoint was the recovery index (RI) measured after the end of the inhalation of Xenon or Isoflurane. In addition the Aldrete score was evaluated up to 180 min. On the first post-operative day the patients rated the quality of the anaesthetic using a scoring system from 1-6.</p> <p>Results</p> <p>The demographics of the groups were similar. The sum score of the SST delivered a clear trend one hour post extubation and a statistically significant superiority for Xenon three hours post extubation (p < 0.01). The RI likewise revealed a statistically significant superiority of Xenon 5 minutes post extubation (p < 0.01). The Aldrete score was significantly higher for 45 min. The scoring system results were also better after Xenon anaesthesia (p < 0.001).</p> <p>Conclusions</p> <p>The results show that recovery from anaesthesia and the early return of post-operative cognitive functions are significantly better after Xenon anaesthesia compared to Isoflurane. The results of the RI for Xenon are similar with the previously published results.</p> <p>Trial Registration</p> <p>The trial was registered with the number ISRCTN01110844 <url>http://www.controlled-trials.com/isrctn/pf/01110844</url>.</p
SAS-6 engineering reveals interdependence between cartwheel and microtubules in determining centriole architecture
Centrioles are critical for the formation of centrosomes, cilia and flagella in eukaryotes. They are thought to assemble around a nine-fold symmetric cartwheel structure established by SAS-6 proteins. Here, we have engineered Chlamydomonas reinhardtii SAS-6-based oligomers with symmetries ranging from five- to ten-fold. Expression of a SAS-6 mutant that forms six-fold symmetric cartwheel structures in vitro resulted in cartwheels and centrioles with eight- or nine-fold symmetries in vivo. In combination with Bld10 mutants that weaken cartwheel-microtubule interactions, this SAS-6 mutant produced six- to eight-fold symmetric cartwheels. Concurrently, the microtubule wall maintained eight- and nine-fold symmetries. Expressing SAS-6 with analogous mutations in human cells resulted in nine-fold symmetric centrioles that exhibited impaired length and organization. Together, our data suggest that the self-assembly properties of SAS-6 instruct cartwheel symmetry, and lead us to propose a model in which the cartwheel and the microtubule wall assemble in an interdependent manner to establish the native architecture of centrioles
Twenty-three unsolved problems in hydrology (UPH) â a community perspective
This paper is the outcome of a community initiative to identify major unsolved scientific problems in hydrology motivated by a need for stronger harmonisation of research efforts. The procedure involved a public consultation through on-line media, followed by two workshops through which a large number of potential science questions were collated, prioritised, and synthesised. In spite of the diversity of the participants (230 scientists in total), the process revealed much about community priorities and the state of our science: a preference for continuity in research questions rather than radical departures or redirections from past and current work. Questions remain focussed on process-based understanding of hydrological variability and causality at all space and time scales.
Increased attention to environmental change drives a new emphasis on understanding how change propagates across interfaces within the hydrological system and across disciplinary boundaries. In particular, the expansion of the human footprint raises a new set of questions related to human interactions with nature and water cycle feedbacks in the context of complex water management problems. We hope that this reflection and synthesis of the 23 unsolved problems in hydrology will help guide research efforts for some years to come
Untersuchungen zur CO2-Methanisierung mittels Fe-Ni-Hydrotalcit-basierter Katalysatoren
Die langfristige Speicherung von ĂŒberschĂŒssiger Energie aus regenerativen Quellen ist ein ungelöstes Problem der Energiewende. Ein Ansatz zur Lösung dieses Problems bietet das Power-to-Gas-Konzept, bei dem Methan aus Wasserstoff und Kohlenstoffdioxid als Ersatz fĂŒr Erdgas erzeugt wird. Da diese Reaktion kinetisch limitiert ist, ist die Verwendung eines geeigneten heterogenen Katalysators erforderlich. Aufgrund ihrer hohen AktivitĂ€t und ihres niedrigen Preises werden hĂ€ufig nickelhaltige Katalysatoren eingesetzt. In der vorliegenden Arbeit wurde die Eignung von Fe-Ni-Hydrotalcit-basierten Katalysatoren fĂŒr dieses Konzept untersucht, wobei der Schwerpunkt auf der Bestimmung der AbhĂ€ngigkeit der katalytischen AktivitĂ€t vom Eisengehalt lag. Dabei zeigte sich, dass geringe Mengen an Eisen die Methanausbeute verbessern. Eine ErklĂ€rung fĂŒr diese AktivitĂ€tssteigerung liefern die Ergebnisse von in-situ-DRIFTS-Untersuchungen an eisenhaltigen und eisenfreien Ni-Hydrotalcit-Katalysatoren
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