122 research outputs found
Integrated optical sensors for disposable microfluidics
Optical chemical sensors are established process monitoring tools in industry and research laboratories. Optical chemical sensors basically comprise of luminescent indicator dye based in a host polymer. They are easy to integrate, non-invasive, do not need any reference element and can be read-out contactless from outside. However, to fully exploit the potential in microfluidic or organ-on- chip devices, the sensors have to fulfil several demands including high brightness, capability to be applied as thin film, excellent photo-stability, cheap and accurate read-out systems, ease in use (simple calibration and drift free), simple mass production compatible preparation steps, compatibility with the chip materials, resistance towards γ-sterilisation and no toxicity. We present sensors for oxygen and pH fulfilling these demands. Our sensors can be excited with red-light and emit light in the near infra-red range (\u3c700 nm). This suppresses background fluorescence and scattering from biological material. Sensor layers or spots are deposited with inkjet-based micro-dispensing or air-brush spraying with good adherence on glass or polymeric materials. A modified miniaturized phase-fluorimeter in a foot-print of a memory stick enables the read-out of sensor sizes below 100 micrometers. The sensor enable dynamic cell culturing and monitoring of cell metabolism in a microfluidic environment. We will give examples of oxygen sensors in a organ-on-chip model and pH sensors in cell cultures.
Please click Additional Files below to see the full abstract
Begründen im Geometrieunterricht als standardisierte (Grund-)Kompetenz
Am Beginn der Arbeit wird die gesetzliche Verankerung der seit 1.1.2009 in Kraft getretenen Bildungsstandards vorgestellt.
Neben Informationen darüber, was Bildungsstandards und Kompetenzen eigentlich sind, wird auch erklärt, woran sich Bildungsstandards orientieren. Nach den Funktionen und Zielen soll diese Arbeit auch über Standardsüberprüfungen Aufschluss geben. Dazu gibt es wieder die Ausführung des gesetzlichen Rahmens und einen kurzen Einblick in die Baseline-Testungen, die bereits im vergangenen Jahr durchgeführt wurden und der Weiterentwicklung der Standards dienen sollen. Am Ende des Kapitels findet man eine ausführliche Beschreibung des Kompetenzmodells mit Musteraufgaben.
Ähnlich dem Kapitel über Bildungsstandards werden im nächsten Kapitel der gesetzliche Rahmen, Funktionen und Ziele der zentralen schriftlichen Reifeprüfung beschrieben. Dabei stellt die Sicherung von Grundkompetenzen ein zentrales Ziel dar. Exemplarisch wird geschildert, was bei der zentralen schriftlichen Reifeprüfung verlangt werden wird. Im Anschluss daran gibt es einen Einblick in die Pilotphase, die seit Jänner 2010 im Gange ist. Ergebnisse des ersten Pilottests fließen dabei ein.
Im Anschluss daran werden im folgenden Kapitel die Bildungsstandards der zentralen schriftlichen Reifeprüfung gegenübergestellt. Gemeinsamkeiten und Punkte, in denen sich die beiden Konzepte voneinander unterscheiden, werden herausgearbeitet.
Im nächsten Kapitel wird erörtert, was man unter Begründen versteht und warum im Mathematikunterricht begründet werden soll. Neben der Argumentationsbasis werden die Schritte des Beweisprozesses beschrieben und analysiert. An Beispielen kommt zum Ausdruck, dass Begründen und Argumentieren auf sehr viele verschiedene Arten möglich ist. Um selbständig einen Beweis führen zu können, bedarf es gewisser Voraussetzungen, die in diesem Abschnitt behandelt werden. Schließlich folgen Methoden, die das Potenzial besitzen, den Lernenden ein Beweisverständnis zu vermitteln. Dazu zählt auch die Arbeit am Computer mittels dynamischer Geometriesoftware.
Nachdem man im letzten Kapitel über die Ursprünge der Geometrie, die schon sehr lange zurückliegen, informiert wird, folgen eine Einbettung der Geometrie in den Lehrplan und eine Aufzählung der Ziele, die der Geometrieunterricht ganz allgemein verfolgt. Schließlich und endlich werden konkret geplante Unterrichtsstunden zu den einzelnen Klassenstufen entwickelt, die den Lernenden (Grund-)Kompetenzen vermitteln sollen
Octamer-binding factor 6 (Oct-6/Pou3f1) is induced by interferon and contributes to dsRNA-mediated transcriptional responses
<p>Abstract</p> <p>Background</p> <p>Octamer-binding factor 6 (Oct-6, Pou3f1, SCIP, Tst-1) is a transcription factor of the Pit-Oct-Unc (POU) family. POU proteins regulate key developmental processes and have been identified from a diverse range of species. Oct-6 expression is described to be confined to the developing brain, Schwann cells, oligodendrocyte precursors, testes, and skin. Its function is primarily characterised in Schwann cells, where it is required for correctly timed transition to the myelinating state. In the present study, we report that Oct-6 is an interferon (IFN)-inducible protein and show for the first time expression in murine fibroblasts and macrophages.</p> <p>Results</p> <p>Oct-6 was induced by type I and type II IFN, but not by interleukin-6. Induction of Oct-6 after IFNβ treatment was mainly dependent on signal transducer and activator of transcription 1 (Stat1) and partially on tyrosine kinase 2 (Tyk2). Chromatin immunopreciptitation experiments revealed binding of Stat1 to the Oct-6 promoter in a region around 500 bp upstream of the transcription start site, a region different from the downstream regulatory element involved in Schwann cell-specific Oct-6 expression. Oct-6 was also induced by dsRNA treatment and during viral infections, in both cases <it>via </it>autocrine/paracrine actions of IFNα/β. Using microarray and RT-qPCR, we furthermore show that Oct-6 is involved in the regulation of transcriptional responses to dsRNA, in particular in the gene regulation of serine/threonine protein kinase 40 (<it>Stk40</it>) and U7 snRNA-associated Sm-like protein Lsm10 (<it>Lsm10)</it>.</p> <p>Conclusion</p> <p>Our data show that Oct-6 expression is not as restricted as previously assumed. Induction of Oct-6 by IFNs and viruses in at least two different cell types, and involvement of Oct-6 in gene regulation after dsRNA treatment, suggest novel functions of Oct-6 in innate immune responses.</p
A time- and dose-dependent STAT1 expression system
BACKGROUND: The signal transducer and activator of transcription (STAT) family of transcription factors mediates a variety of cytokine dependent gene regulations. STAT1 has been mainly characterized by its role in interferon (IFN) type I and II signaling and STAT1 deficiency leads to high susceptibility to several pathogens. For fine-tuned analysis of STAT1 function we established a dimerizer-inducible system for STAT1 expression in vitro and in vivo. RESULTS: The functionality of the dimerizer-induced STAT1 system is demonstrated in vitro in mouse embryonic fibroblasts and embryonic stem cells. We show that this two-vector based system is highly inducible and does not show any STAT1 expression in the absence of the inducer. Reconstitution of STAT1 deficient cells with inducible STAT1 restores IFNγ-mediated gene induction, antiviral responses and STAT1 activation remains dependent on cytokine stimulation. STAT1 expression is induced rapidly upon addition of dimerizer and expression levels can be regulated in a dose-dependent manner. Furthermore we show that in transgenic mice STAT1 can be induced upon stimulation with the dimerizer, although only at low levels. CONCLUSION: These results prove that the dimerizer-induced system is a powerful tool for STAT1 analysis in vitro and provide evidence that the system is suitable for the use in transgenic mice. To our knowledge this is the first report for inducible STAT1 expression in a time- and dose-dependent manner
Transcriptome analysis reveals a major impact of JAK protein tyrosine kinase 2 (Tyk2) on the expression of interferon-responsive and metabolic genes
<p>Abstract</p> <p>Background</p> <p>Tyrosine kinase 2 (Tyk2), a central component of Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling, has major effects on innate immunity and inflammation. Mice lacking Tyk2 are resistant to endotoxin shock induced by lipopolysaccharide (LPS), and Tyk2 deficient macrophages fail to efficiently induce interferon α/β after LPS treatment. However, how Tyk2 globally regulates transcription of downstream target genes remains unknown. Here we examine the regulatory role of Tyk2 in basal and inflammatory transcription by comparing gene expression profiles of peritoneal macrophages from Tyk2 mutant and wildtype control mice that were either kept untreated or exposed to LPS for six hours.</p> <p>Results</p> <p>Untreated Tyk2-deficient macrophages exhibited reduced expression of immune response genes relative to wildtype, in particular those that contain interferon response elements (IRF/ISRE), whereas metabolic genes showed higher expression. Upon LPS challenge, IFN-inducible genes (including those with an IRF/ISRE transcription factor binding-site) were strongly upregulated in both Tyk2 mutant and wildtype cells and reached similar expression levels. In contrast, metabolic gene expression was strongly decreased in wildtype cells upon LPS treatment, while in Tyk2 mutant cells the expression of these genes remained relatively unchanged, which exaggerated differences already present at the basal level. We also identified several 5'UR transcription factor binding-sites and 3'UTR regulatory elements that were differentially induced between Tyk2 deficient and wildtype macrophages and that have not previously been implicated in immunity.</p> <p>Conclusions</p> <p>Although Tyk2 is essential for the full LPS response, its function is mainly required for baseline expression but not LPS-induced upregulation of IFN-inducible genes. Moreover, Tyk2 function is critical for the downregulation of metabolic genes upon immune challenge, in particular genes involved in lipid metabolism. Together, our findings suggest an important regulatory role for Tyk2 in modulating the relationship between immunity and metabolism.</p
Qualitätsentwicklung in Studium und Lehre durch Design-Based Research
Design-Based Research (DBR) is a methodology to improve the quality of learning and teaching in education. After identifying and analysing a problem, a prototyp solution is developed, tested and refined in practice in iterative cycles. Design principles are produced to enhance solution implementation. We present four DBR projects from different disciplines and discuss the generalizability of the results and their relevance for the quality development in higher education. We identified a potential for generalizability in all projects, further evaluation steps are missing. A lack of resources or structural changes within the presented projects may lead to an early termination without a final design refinement and an implementation of design principles.Design-Based Research (DBR) ist eine Methodologie zur Verbesserung der Qualität von Lernen und Lehren. Das zyklisch-iterative Vorgehen zielt auf die Lösung eines konkreten Bildungsproblems und die Ableitung generalisierbarer Erkenntnisse in Form von Design-Prinzipien. Vier DBR-Projekte aus unterschiedlichen Fachdisziplinen werden vorgestellt und die Frage der Generalisierbarkeit der Projekterkenntnisse und deren Relevanz für die Qualitätsentwicklung von Studium und Lehre diskutiert. In allen Projekten zeigt sich ein Generalisierungspotenzial, es fehlen weitere Evaluationsschritte. Mangelnde Ressourcen oder strukturelle Veränderungen führten zur Beendigung einiger DBR-Projekte vor abschließender Designanpassung und Erprobung
Tyrosine kinase 2 promotes sepsis‐associated lethality by facilitating production of interleukin‐27
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141056/1/jlb0123-sup-0001.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/141056/2/jlb0123.pd
Symptoms in unilateral vestibular hypofunction are associated with number of catch-up saccades and retinal error
- …