38 research outputs found

    Mobile Anwendungssysteme im Gesundheitswesen: eine empirische Anforderungsanalyse am Beispiel der prÀklinischen Notfallmedizin

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    Viele GeschĂ€ftsprozesse in der Unternehmenspraxis werden bereits wirkungsvoll durch mobile Anwendungssysteme unterstĂŒtzt. Von ĂŒberall sind Informationen aller Art zugĂ€nglich und können wĂ€hrend der ProzessausfĂŒhrung abgerufen und weiterverarbeitet werden. Dieser Trend wird auch vermehrt in der prĂ€klinischen Notfallmedizin Einzug halten, wo bereits spezialisierte Systeme fĂŒr einige wenige Krankheitsbilder und Teilprozesse eingebracht werden. Im Rahmen dieses Beitrags wird auf Basis einer Anforderungserhebung per Online-Umfrage ein erster theoretischer Ansatz abgeleitet, welcher die Grundlage bietet die EinsatzkrĂ€fte direkt im Notfalleinsatz bei der Behandlung des Patienten durch prozessorientierte Informationsweitergabe, sowie in relevanten vor- und nachgelagerten Prozessen zu unterstĂŒtzen

    Nucleosome eviction from MHC class II promoters controls positioning of the transcription start site

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    Nucleosome depletion at transcription start sites (TSS) has been documented genome-wide in multiple eukaryotic organisms. However, the mechanisms that mediate this nucleosome depletion and its functional impact on transcription remain largely unknown. We have studied these issues at human MHC class II (MHCII) genes. Activation-induced nucleosome free regions (NFR) encompassing the TSS were observed at all MHCII genes. Nucleosome depletion was exceptionally strong, attaining over 250-fold, at the promoter of the prototypical HLA-DRA gene. The NFR was induced primarily by the transcription factor complex that assembles on the conserved promoter-proximal enhancer situated upstream of the TSS. Functional analyses performed in the context of native chromatin demonstrated that displacing the NFR without altering the sequence of the core promoter induced a shift in the position of the TSS. The NFR thus appears to play a critical role in transcription initiation because it directs correct TSS positioning in vivo. Our results provide support for a novel mechanism in transcription initiation whereby the position of the TSS is controlled by nucleosome eviction rather than by promoter sequence

    The Light Responsive Transcriptome of the Zebrafish: Function and Regulation

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    Most organisms possess circadian clocks that are able to anticipate the day/night cycle and are reset or “entrained” by the ambient light. In the zebrafish, many organs and even cultured cell lines are directly light responsive, allowing for direct entrainment of the clock by light. Here, we have characterized light induced gene transcription in the zebrafish at several organizational levels. Larvae, heart organ cultures and cell cultures were exposed to 1- or 3-hour light pulses, and changes in gene expression were compared with controls kept in the dark. We identified 117 light regulated genes, with the majority being induced and some repressed by light. Cluster analysis groups the genes into five major classes that show regulation at all levels of organization or in different subset combinations. The regulated genes cover a variety of functions, and the analysis of gene ontology categories reveals an enrichment of genes involved in circadian rhythms, stress response and DNA repair, consistent with the exposure to visible wavelengths of light priming cells for UV-induced damage repair. Promoter analysis of the induced genes shows an enrichment of various short sequence motifs, including E- and D-box enhancers that have previously been implicated in light regulation of the zebrafish period2 gene. Heterologous reporter constructs with sequences matching these motifs reveal light regulation of D-box elements in both cells and larvae. Morpholino-mediated knock-down studies of two homologues of the D-box binding factor Tef indicate that these are differentially involved in the cell autonomous light induction in a gene-specific manner. These findings suggest that the mechanisms involved in period2 regulation might represent a more general pathway leading to light induced gene expression

    Kidney transplant monitoring by urinary flow cytometry: Biomarker combination of T cells, renal tubular epithelial cells, and podocalyxin-positive cells detects rejection

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    Creatinine and proteinuria are used to monitor kidney transplant patients. However, renal biopsies are needed to diagnose renal graft rejection. Here, we assessed whether the quantification of different urinary cells would allow non-invasive detection of rejection. Urinary cell numbers of CD4+ and CD8+ T cells, monocytes/macrophages, tubular epithelial cells (TEC), and podocalyxin(PDX)-positive cells were determined using flow cytometry and were compared to biopsy results. Urine samples of 63 renal transplant patients were analyzed. Patients with transplant rejection had higher amounts of urinary T cells than controls; however, patients who showed worsening graft function without rejection had similar numbers of T cells. T cells correlated with histological findings (interstitial inflammation p = 0.0005, r = 0.70; tubulitis p = 0.006, r = 0.58). Combining the amount of urinary T cells and TEC, or T cells and PDX+ cells, yielded a significant segregation of patients with rejection from patients without rejection (all p < 0.01, area under the curve 0.89–0.91). Urinary cell populations analyzed by flow cytometry have the potential to introduce new monitoring methods for kidney transplant patients. The combination of urinary T cells, TEC, and PDX-positive cells may allow non-invasive detection of transplant rejection

    Polymer-based hybrid photonic integration for flexible PIC design

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    Recent developments in polymer-based photonic components allow for a novel PIC design approach bridging free-space optics, integrated optics and high-speed electronics

    Pseudovertical Schottky Diodes on Heteroepitaxially Grown Diamond

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    Substrates comprising heteroepitaxially grown single-crystalline diamond epilayers were used to fabricate pseudovertical Schottky diodes. These consisted of Ti/Pt/Au contacts on p− Boron-doped diamond (BDD) layers (1015–1016 cm−3) with varying thicknesses countered by ohmic contacts on underlying p+ layers (1019–1020 cm−3) on the quasi-intrinsic diamond starting substrate. Whereas the forward current exhibited a low-voltage shunt conductance and, for higher voltages, thermionic emission behavior with systematic dependence on the p− film thickness, the reverse leakage current appeared to be space-charge-limited depending on the existence of local channels and thus local defects, and depending less on the thickness. For the Schottky barriers ϕSB, a systematic correlation to the ideality factors n was observed, with an “ideal” n = 1 Schottky barrier of ϕSB = 1.43 eV. For the best diodes, the breakdown field reached 1.5 MV/cm

    Gbit/s-operation of graphene electro-absorption modulators in a passive polymer waveguide platform for data and telecommunications

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    Graphene with its high carrier mobility as well as its tunable light absorption is an attractive active material for highspeed electro-absorption modulators (EAMs). Large-area CVD-grown graphene monolayers can be transferred onto arbitrary substrates to add active optoelectronic properties to intrinsically passive photonic integration platforms. In this work, we present graphene-based EAMs integrated in passive polymer waveguides. To facilitate modulation frequencies in the GHz range, a 50 Ω termination resistor as well as a DC blocking capacitor are integrated with graphene EAMs for the first time. Large signal data transmission experiments were carried out across the O, C and L optical communications bands. The fastest devices exhibit a 3-dB bandwidth of more than 4 GHz. Our analytical model of the modulation response for the graphene-based EAMs is in good agreement with the measurement results. It predicts that bandwidths greater than 50 GHz are possible with future device iterations. Owing to the absorption properties of the graphene layers, the devices are expected to be functional at smaller wavelengths of interest for optical interconnects and data-communications as well, offering a novel flexibility for the integration of high-speed functionalities in optoelectronic integrated circuits. Our work is the first step towards an Active Optical Printed Circuit Board, hiding the optics completely inside the board and thus removing entry barriers in manufacturing. We believe this will lead to the same success as observed in Active Optical Cables for short range optically wired connections

    Pseudovertical Schottky Diodes on Heteroepitaxially Grown Diamond

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    Substrates comprising heteroepitaxially grown single-crystalline diamond epilayers were used to fabricate pseudovertical Schottky diodes. These consisted of Ti/Pt/Au contacts on p&minus; Boron-doped diamond (BDD) layers (1015&ndash;1016 cm&minus;3) with varying thicknesses countered by ohmic contacts on underlying p+ layers (1019&ndash;1020 cm&minus;3) on the quasi-intrinsic diamond starting substrate. Whereas the forward current exhibited a low-voltage shunt conductance and, for higher voltages, thermionic emission behavior with systematic dependence on the p&minus; film thickness, the reverse leakage current appeared to be space-charge-limited depending on the existence of local channels and thus local defects, and depending less on the thickness. For the Schottky barriers &#981;SB, a systematic correlation to the ideality factors n was observed, with an &ldquo;ideal&rdquo; n = 1 Schottky barrier of &#981;SB = 1.43 eV. For the best diodes, the breakdown field reached 1.5 MV/cm
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