85 research outputs found

    From a Sensitive Topic to a Quality Feature – The Corona Pandemic as a Gamechanger for Early Childhood Media Education? An Analysis of new Potentials of the Pandemic-Related Digitization Processes in German Child Day Care Facilities

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    WĂ€hrend des ersten Covid-19-bedingten Lockdowns wurden die Rufe nach einer umfassenden Digitalisierung von Bildungsinstitutionen laut. Die Vermittlung von dafĂŒr notwendigen frĂŒhkindlichen Medienkompetenzen ist jedoch noch lange nicht im Alltag von Kitas angekommen. Es stellt sich die Frage, inwieweit die Extremsituation, in der sich Kitas und Familien wĂ€hrend des ersten Lockdowns befanden, einen Gamechanger darstellt: Konnten die ausgelösten Digitalisierungsprozesse Eltern und FachkrĂ€fte fĂŒr die Potenziale digitaler Medien in der Kita sensibilisieren? Und inwieweit konnten FachkrĂ€fte im Umgang mit digitalen Medien Hemmungen abbauen und Kompetenzen stĂ€rken? In der vorgestellten mehrstufigen Mixed-Methods-Studie wurden zwischen MĂ€rz und Dezember 2020 in zehn KindertagesstĂ€tten sowohl Eltern als auch FachkrĂ€fte befragt. Die Ergebnisse zeigen, dass es durch den ersten Lockdown in den befragten Kitas diverse Anstösse hin zu einer offeneren und positiveren Grundhaltung gegenĂŒber digitalen Medien gab. Etablierte analoge Praktiken wurden in vielen Bereichen aufgebrochen oder ĂŒberdacht und stĂ€rker digitalisiert. Seitens der Eltern lassen sich – trotz einer Zunahme der kindlichen Mediennutzung im ersten Lockdown – keine wesentlichen HaltungsverĂ€nderungen hinsichtlich der Notwendigkeit einer gezielten Medienerziehung beobachten. Die Ergebnisse deuten darauf hin, dass die positiven Erfahrungen, die Kitas mit digitalen Medien gemacht haben, ein notwendiger erster Schritt zu einer nachhaltigen Verankerung von MedienpĂ€dagogik, jedoch keineswegs ein â€čSelbstlĂ€uferâ€ș sind.During the first Covid-19-related lockdown in Germany, demands for the comprehensive digitization of educational institutions got louder. However, media education in early childcare institutions is still hardly integrated into daily practices of daycare centers. The question arises to what extent the extreme situation in which daycare centers and families found themselves during the first lockdown was a gamechanger: Were the triggered digitization processes able to raise awareness among parents and professionals for the potentials of digital media in daycare institutions? And to what extent were professionals able to reduce their inhibitions and strengthen their competencies in dealing with digital media? In the present mixed-methods study composed of semi-structured interviews and a quantitative questionnaire, parents and professionals of ten daycare centers were surveyed and interviewed between March and December 2020. The results show that the first lockdown provided various impulses for a more open and positive attitude towards digital media. Established non-digital practices were broken up or reconsidered in many areas. Despite the increase in children‘s use of media in the first lockdown, no significant changes in attitude regarding the need for media education was observed on the part of parents. The results suggest that the positive experiences that daycare centers had with digital media are a necessary first step towards a more sustainably anchored media education - but by no means a foregone conclusion

    Lipidische flĂŒssigkristalline Phasen : Neue Konzepte zur Immobilisierung von Enzymen und Membranproteinen fĂŒr biosensorische Anwendungen

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    Eine elegante und erst in den letzten Jahren intensiv untersuchte Möglichkeit zur Immobilisierung von BiomolekĂŒlen ist die Verwendung lipidischer flĂŒssigkristalliner Phasen. Sie zeichnen sich dadurch aus, dass die LipidmolekĂŒle in einer membranĂ€hnlichen Anordnung vorliegen und in dieser frei beweglich sind. In der rĂ€umlichen Anordnung gibt es, Ă€hnlich wie in einem Kristall, sich wiederholende Strukturen. FlĂŒssigkristalle sind thermodynamisch stabil und wurden zuerst durch Luzatti et al. beschrieben. Bekanntestes Beispiel ist synthetisch hergestelltes 1-rac-Monoolein. Diese Substanz bildet eine kubische bikontinuierliche lipidisch flĂŒssigkristalline Phase mit definierten Eigenschaften. Die Stabilisierung der BiomolekĂŒle erfolgt durch Einlagerung in diese lipidisch flĂŒssigkristallinen Strukturen. Sie bilden ein hoch-viskoses optisch transparentes stabiles Zweiphasensystem, bestehend aus dem immobilisierten BiomolekĂŒl und der wĂ€ssrigen Lösung, in der die Analsten gelöst sind. Die FlĂŒssigkristalle lassen sich vorteilhaft als dĂŒnne Schicht auf diverse OberflĂ€chenmaterialien auftragen, z.B. auf optischen oder elektrischen Sensoren. Bislang sind die Einsatzmöglichkeiten allerdings beschrĂ€nkt, da nur wenige Systeme zur VerfĂŒgung stehen, die darĂŒber hinaus fĂŒr den technischen Einsatz zu kostenintensiv sind. Wir berichten hier ĂŒber eine neue innovative Möglichkeit, lipidische flĂŒssigkristalline Phasen zu bilden und fĂŒr Biosensoren einzusetzen. Die fĂŒr die Immobilisierung verwendeten Monoglyceride werden durch alkalische Alkoholyse aus Pflanzenölen gewonnen. Sie stellen ein Gemisch von Monoglyceriden unterschiedlicher KettenlĂ€nge dar, deren Zusammensetzung vom Pflanzenöl bestimmt wird. Durch die gezielte Zusammenstellung der Ausgangsmaterialien können die Matrixeigenschaften hinsichtlich der Wechselwirkung mit den BiomolekĂŒlen optimiert werden

    Isoprenoid Pathway Optimization for Taxol Precursor Overproduction in Escherichia coli

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    Author Manuscript February 6, 2011Taxol (paclitaxel) is a potent anticancer drug first isolated from the Taxus brevifolia Pacific yew tree. Currently, cost-efficient production of Taxol and its analogs remains limited. Here, we report a multivariate-modular approach to metabolic-pathway engineering that succeeded in increasing titers of taxadiene—the first committed Taxol intermediate—approximately 1 gram per liter (~15,000-fold) in an engineered Escherichia coli strain. Our approach partitioned the taxadiene metabolic pathway into two modules: a native upstream methylerythritol-phosphate (MEP) pathway forming isopentenyl pyrophosphate and a heterologous downstream terpenoid–forming pathway. Systematic multivariate search identified conditions that optimally balance the two pathway modules so as to maximize the taxadiene production with minimal accumulation of indole, which is an inhibitory compound found here. We also engineered the next step in Taxol biosynthesis, a P450-mediated 5α-oxidation of taxadiene to taxadien-5α-ol. More broadly, the modular pathway engineering approach helped to unlock the potential of the MEP pathway for the engineered production of terpenoid natural products

    Cell-Based Sensor System Using L6 Cells for Broad Band Continuous Pollutant Monitoring in Aquatic Environments

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    Pollution of drinking water sources represents a continuously emerging problem in global environmental protection. Novel techniques for real-time monitoring of water quality, capable of the detection of unanticipated toxic and bioactive substances, are urgently needed. In this study, the applicability of a cell-based sensor system using selected eukaryotic cell lines for the detection of aquatic pollutants is shown. Readout parameters of the cells were the acidification (metabolism), oxygen consumption (respiration) and impedance (morphology) of the cells. A variety of potential cytotoxic classes of substances (heavy metals, pharmaceuticals, neurotoxins, waste water) was tested with monolayers of L6 cells (rat myoblasts). The cytotoxicity or cellular effects induced by inorganic ions (Ni2+ and Cu2+) can be detected with the metabolic parameters acidification and respiration down to 0.5 mg/L, whereas the detection limit for other substances like nicotine and acetaminophen are rather high, in the range of 0.1 mg/L and 100 mg/L. In a close to application model a real waste water sample shows detectable signals, indicating the existence of cytotoxic substances. The results support the paradigm change from single substance detection to the monitoring of overall toxicity

    Du Frense, William A.; Interview and Materials

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    Roster Number: 1064. Picture Location: Box 8 Folder 1. Interview Location: Box 4 Folder 1

    Straightforward Approach for Electrochemical Deposition and Modification of Conductive Polythiophene Thin Films for Bioreceptor Immobilization

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    Biosensors offer exciting opportunities for various clinical applications and constitute a rapidly growing research branch due to new generations of bioreceptors, transducers, and biomaterials with versatile characteristics, such as conductive polymers. Polythiophene is a prominent example of conducting polymers and convinces with excellent conductivity and stability—and is yet barely used for the construction of biosensors. We want to address the fundamental lack of straightforward fabrication procedures for bioreceptor immobilization platforms based on polythiophene. We investigate the literature-known monomer 3-thiopheneacetic acid and present our newly developed method for electrochemical coupling of the linker p-aminobenzoic acid to deposited polythiophene films. Aminated bioreceptors can subsequently be immobilized via EDC/NHS click chemistry. Films were electropolymerized and modified by chronopotentiometry, characterized by electrochemical impedance spectroscopy, surface-enhanced Raman spectroscopy, as well as energy-dispersive X-ray spectroscopy. Both of the presented methods allow for the fabrication of functionalized polythiophene thin films of high conductivity and good reproducibility while convincing with their ease in synthesis

    Starter Kit for Electrochemical Sensors Based on Polythiophene Thin Films—Synthesis of High-Quality Films and Protocol for Fast and Gentle Electrode Regeneration

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    Due to their unique properties, polythiophene and other conductive polymers have become the subject of intensive research and are promising substrate materials for innovative and trendsetting applications. To this day, boron trifluoride diethyl etherate (BFEE) is the preferred solvent for the electropolymerization of thiophene, although it does not allow for reproducible film qualities due to its decomposition under ambient conditions. We therefore want to equip the reader with a starter kit for the electropolymerization of high-quality polythiophene films from stable solvents and a simple yet efficient method to remove the deposited films from the electrodes for their reuse. By drying the working solution prior to its utilization, and by adding a Lewis acid catalyst, films that display enhanced electron transfer and a smooth surface topography can be obtained, which can both be beneficial for the analytic performance of a subsequently built biosensor
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