127 research outputs found

    Metal free graphene synthesis on insulating or semiconducting substrates

    Get PDF
    The present invention relates to a process for preparing graphene by chemical vapour deposition (CVD), wherein an insulating or semiconducting inorganic substrate is provided in a chemical vapour deposition (CVD) reactor and subjected to a thermal pre-treatment in a hydrogen-containing atmosphere,and graphene is deposited on the inorganic substrate by bringing a gaseous oxidant and a carbon-containing precursor into contact with the inorganic substrate

    Investigation of intraocular pressure fluctuation as a risk factor of glaucoma progression

    Get PDF
    Purpose: Since the role of short- and long-term intraocular pressure (IOP) fluctuation as a predictor of glaucoma progression is still controversial, the purpose of this study was to investigate the role of IOP fluctuation in a non-selected patient cohort. Materials and methods: Two-hundred and forty eyes of 120 glaucoma patients (51% female) with a mean age of 64.5 years were included. Inclusion criteria were at least a visual field (VF) and a 48-hour diurnal phasing of IOP including nocturnal measurement. Glaucoma Progression was defined as – if available – confirmed progression of reproducible VF defects in at least three VF examinations or increase of cup area on optic nerve imaging (Heidelberg Retina Tomograph [HRT]) with at least two images after baseline. If results were stable or less than previously mentioned VF or HRT examinations were available, it was classified as “no progression”. Results: Glaucoma progression was seen in seven of 240 eyes in the VF analysis and ten of 240 eyes on HRT. Of all 240 eyes, 92 and 41 eyes fulfilled the criteria to be included for progression evaluation on VF and HRT analysis, respectively. Mean time to progression ± standard error was 3.6±0.2 years on VF and 4.5±0.3 years on HRT. Univariate and multivariate Cox regression analyses revealed short-term IOP fluctuation (P,0.0001) and maximum IOP (P,0.001) as risk factors for glaucoma progression on VF. There was no significant influence of demographic characteristics, ocular or general health on glaucoma progression. Conclusion: Short-term IOP fluctuation was associated with the progression of glaucoma in this non-selected cohort of glaucoma patients receiving phasing of IOP. Keywords: glaucoma progression, short-term IOP fluctuation, long-term IOP fluctuation, glaucoma imaging, visual fiel

    Investigation of intraocular pressure fluctuation as a risk factor of glaucoma progression

    Get PDF
    Purpose: Since the role of short- and long-term intraocular pressure (IOP) fluctuation as a predictor of glaucoma progression is still controversial, the purpose of this study was to investigate the role of IOP fluctuation in a non-selected patient cohort. Materials and methods: Two-hundred and forty eyes of 120 glaucoma patients (51% female) with a mean age of 64.5 years were included. Inclusion criteria were at least a visual field (VF) and a 48-hour diurnal phasing of IOP including nocturnal measurement. Glaucoma Progression was defined as – if available – confirmed progression of reproducible VF defects in at least three VF examinations or increase of cup area on optic nerve imaging (Heidelberg Retina Tomograph [HRT]) with at least two images after baseline. If results were stable or less than previously mentioned VF or HRT examinations were available, it was classified as “no progression”. Results: Glaucoma progression was seen in seven of 240 eyes in the VF analysis and ten of 240 eyes on HRT. Of all 240 eyes, 92 and 41 eyes fulfilled the criteria to be included for progression evaluation on VF and HRT analysis, respectively. Mean time to progression ± standard error was 3.6±0.2 years on VF and 4.5±0.3 years on HRT. Univariate and multivariate Cox regression analyses revealed short-term IOP fluctuation (P,0.0001) and maximum IOP (P,0.001) as risk factors for glaucoma progression on VF. There was no significant influence of demographic characteristics, ocular or general health on glaucoma progression. Conclusion: Short-term IOP fluctuation was associated with the progression of glaucoma in this non-selected cohort of glaucoma patients receiving phasing of IOP. Keywords: glaucoma progression, short-term IOP fluctuation, long-term IOP fluctuation, glaucoma imaging, visual fiel

    Vermischungsvorgänge in der unteren Troposphäre über orographisch strukturiertem Gelände. Ein Beitrag zum EUROTRAC-Teilprojekt TRACT

    Get PDF
    Meteorologische und luftchemische Messungen, die während der TRACT Feldmeßkampagne im September 1992 in Südwestdeutschland, Ostfrankreich und der Nordschweiz durchgeführt wurden, zeigen einen starken Einfluß der Orographie auf die vertikale Durchmischung und den Horizontaltransport von Luftmassen in der unteren Troposphäre während Schönwetterlagen. Detaillierte Untersuchungen der konvektiven Grenzschichtentwicklung werden sowohl anhand von Meßdaten als auch mittels einfacher Modellrechnungen durchgeführt. Es werden verschiedene Parametrisierungen der Grenzschichtentwicklung diskutiert, die orographisch bedingte Advektionseffekte berücksichtigen und somit zu einer besseren Beschreibung der Grenzschichthöhe über unebenem Gelände beitragen. Über hügeligem Gelände wird der Austausch zwischen der atmosphärischen Grenzschicht und der freien Troposphäre (Handover) durch Stufen in der Grenzschichthöhe und Durchbrüche in der Grenzschichtinversion verstärkt. Regionale Windsysteme entlang der großen Täler zwischen den Gebirgen bewirken einen Transport von Luftverunreinigungen zwischen verschiedenen städtischen Ballungszentren. Diesen regionalen Luftströmungen sind thermisch induzierte Zirkulationssysteme an den Berghängen und in den Seitentälern der Gebirge überlagert, die zu einem Luftmassenaustausch zwischen den dicht besiedelten Tälern mit hohen Emissionen und den ländlichen Bergregionen führen. Es wird gezeigt, daß hierbei die nächtlichen Bergwinde zu sekundären Ozonmaxima an Talstationen führen können. Geländebeeinflußte Nebelverteilungen bewirken starke räumliche Unterschiede in den Spurengasverteilungen und in der Grenzschichthöhe und begünstigen somit das Handover an Grenzschichtstufen

    Digital research data: from analysis of existing standards to a scientific foundation for a modular metadata schema in nanosafety

    Get PDF
    Background: Assessing the safety of engineered nanomaterials (ENMs) is an interdisciplinary and complex process producing huge amounts of information and data. To make such data and metadata reusable for researchers, manufacturers, and regulatory authorities, there is an urgent need to record and provide this information in a structured, harmonized, and digitized way. Results: This study aimed to identify appropriate description standards and quality criteria for the special use in nanosafety. There are many existing standards and guidelines designed for collecting data and metadata, ranging from regulatory guidelines to specific databases. Most of them are incomplete or not specifically designed for ENM research. However, by merging the content of several existing standards and guidelines, a basic catalogue of descriptive information and quality criteria was generated. In an iterative process, our interdisciplinary team identified deficits and added missing information into a comprehensive schema. Subsequently, this overview was externally evaluated by a panel of experts during a workshop. This whole process resulted in a minimum information table (MIT), specifying necessary minimum information to be provided along with experimental results on effects of ENMs in the biological context in a flexible and modular manner. The MIT is divided into six modules: general information, material information, biological model information, exposure information, endpoint read out information and analysis and statistics. These modules are further partitioned into module subdivisions serving to include more detailed information. A comparison with existing ontologies, which also aim to electronically collect data and metadata on nanosafety studies, showed that the newly developed MIT exhibits a higher level of detail compared to those existing schemas, making it more usable to prevent gaps in the communication of information. Conclusion: Implementing the requirements of the MIT into e.g., electronic lab notebooks (ELNs) would make the collection of all necessary data and metadata a daily routine and thereby would improve the reproducibility and reusability of experiments. Furthermore, this approach is particularly beneficial regarding the rapidly expanding developments and applications of novel non-animal alternative testing methods

    Relation between arterial stiffness and markers of inflammation and hemostasis : data from the population-based Gutenberg Health Study

    Get PDF
    The relation between inflammation, hemostasis and arterial stiffness is of pathophysiological relevance for the development of cardiovascular disease (CVD). Data investigating this interplay using stiffness index (SI) by digital photoplethysmography are not available yet. Therefore, sex-specific relation between SI and inflammatory and hemostatic biomarkers was investigated within 13,724 subjects from the population-based Gutenberg Health Study. C-reactive protein (CRP), white blood cell count (WBCC), neopterin, interleukin-18, interleukin-1 receptor antagonist (IL-1RA), fibrinogen and hematocrit were measured. Multivariable linear regression analysis with adjustment for cardiovascular risk factors, medication, and hormonal status (in females) revealed an independent association between SI and WBCC, IL-1RA and hematocrit in both sexes, and with fibrinogen in women. There was a joint effect of increasing tertiles of SI and biomarker concentrations for future CVD risk prediction. Subjects with both SI and biomarker concentration above the median had the worst overall survival and with both below the median the best survival during a follow-up period of 6.2 ± 1.7 years, except for hematocrit. The results support the relation between inflammation, hemostasis and arterial stiffness measured by digital photoplethysmography. Markers of inflammation and hemostasis modulate the ability of SI to identify subjects at risk for future CVD or higher mortality

    Critical Behaviour of Superfluid 4^4He in Aerogel

    Full text link
    We report on Monte Carlo studies of the critical behaviour of superfluid 4^4He in the presence of quenched disorder with long-range fractal correlations. According to the heuristic argument by Harris, uncorrelated disorder is irrelevant when the specific heat critical exponent α\alpha is negative, which is the case for the pure 4^4He. However, experiments on helium in aerogel have shown that the superfluid density critical exponent ζ\zeta changes. We hypothesize that this is a cross-over effect due to the fractal nature of aerogel. Modelling the aerogel as an incipient percolating cluster in 3D and weakening the bonds at the fractal sites, we perform XY-model simulations, which demonstrate an increase in ζ\zeta from 0.67±0.0050.67 \pm 0.005 for the pure case to an apparent value of 0.722±0.0050.722\pm 0.005 in the presence of the fractal disorder, provided that the helium correlation length does not exceed the fractal correlation length.Comment: 4 pages, RevTex, 3 postscript figures, LaTeX file and figures have been uuencoded

    Genomic and transcriptomic changes complement each other in the pathogenesis of sporadic Burkitt lymphoma

    Get PDF
    Burkitt lymphoma (BL) is the most common B-cell lymphoma in children. Within the International Cancer Genome Consortium (ICGC), we performed whole genome and transcriptome sequencing of 39 sporadic BL. Here, we unravel interaction of structural, mutational, and transcriptional changes, which contribute to MYC oncogene dysregulation together with the pathognomonic IG-MYC translocation. Moreover, by mapping IGH translocation breakpoints, we provide evidence that the precursor of at least a subset of BL is a B-cell poised to express IGHA. We describe the landscape of mutations, structural variants, and mutational processes, and identified a series of driver genes in the pathogenesis of BL, which can be targeted by various mechanisms, including IG-non MYC translocations, germline and somatic mutations, fusion transcripts, and alternative splicing

    Increased risk of severe clinical course of COVID-19 in carriers of HLA-C*04:01

    Get PDF
    Background: Since the beginning of the coronavirus disease 2019 (COVID-19) pandemic, there has been increasing urgency to identify pathophysiological characteristics leading to severe clinical course in patients infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Human leukocyte antigen alleles (HLA) have been suggested as potential genetic host factors that affect individual immune response to SARS-CoV-2. We sought to evaluate this hypothesis by conducting a multicenter study using HLA sequencing. Methods: We analyzed the association between COVID-19 severity and HLAs in 435 individuals from Germany (n = 135), Spain (n = 133), Switzerland (n = 20) and the United States (n = 147), who had been enrolled from March 2020 to August 2020. This study included patients older than 18 years, diagnosed with COVID19 and representing the full spectrum of the disease. Finally, we tested our results by meta-analysing data from prior genome-wide association studies (GWAS). Findings: We describe a potential association of HLA-C*04:01 with severe clinical course of COVID-19. Carriers of HLA-C*04:01 had twice the risk of intubation when infected with SARS-CoV-2 (risk ratio 1.5 [95% CI 1.1-2.1], odds ratio 3.5 [95% CI 1.9-6.6], adjusted p-value = 0.0074). These findings are based on data from four countries and corroborated by independent results from GWAS. Our findings are biologically plausible, as HLA-C*04:01 has fewer predicted bindings sites for relevant SARS-CoV-2 peptides compared to other HLA alleles. Interpretation: HLA-C*04:01 carrier state is associated with severe clinical course in SARS-CoV-2. Our findings suggest that HLA class I alleles have a relevant role in immune defense against SARS-CoV-2. Funding: Funded by Roche Sequencing Solutions, Inc
    • …
    corecore