20 research outputs found

    Robust estimation of bacterial cell count from optical density

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    Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

    Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

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    IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

    "Some day I will go to Germany" : longitudinal study concerning the motivation for learning German at university in Japan

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    Deutschlernende an japanischen Universitäten haben keine Zukunftsvorstellung von sich zur Anwendung von Fremdsprachen, obwohl sie die Nützlichkeit von Fremdsprachen, zum Beispiel auf Reisen, generell hoch einschätzen. Dem Deutschunterricht wird eine grundlegend positive Einstellung entgegengebracht. Fachspezifische Unterschiede in dieser Sichtweise werden vor allem bei Pharmaziestudierenden deutlich. Diese wünschen sich eine stärkere Verzahnung von sprachlichen und fachlichen Inhalten. Dies sind Ergebnisse der vorliegenden Arbeit, welche sich mit der Motivation Studierender zum Erlernen der Fremdsprache Deutsch an einer Universität in Japan beschäftigt. Grundlage der Untersuchungen ist das von Zoltán Dörnyei entwickelte L2 Motivational Self System. Dieses besagt, dass folgende drei Komponenten die Motivation der Fremdsprachenlernenden bestimmen: das Ideal-L2-Selbst, das Soll-L2-Selbst sowie die Zielsprachenlernerfahrung. Um die Veränderung der Motivation während des einjährigen Deutschlernens zu ermitteln, wurden Fragebogenerhebungen zu zwei Messzeitpunkten, zu Beginn und am Ende des Deutschlernens, durchgeführt. Des Weiteren wurden Sprachlernmotivationsbiographien nach Riemer hinzugezogen, um die Erkenntnisse zu vervollständigen. Als Konsequenz aus den Ergebnissen, wird die Möglichkeit des Einsatzes von Dörnyeis 6-Punkte-Plan zur Erarbeitung eines Ideal-L2-Selbst, sowie die Arbeit mit dem Europäischen Sprachenportfolio im Deutschunterricht in Japan erläutert.Students, who learn German at a Japanese university, have no vision of themselves using foreign languages, even though they value the usefulness of foreign languages, for example when travelling. There is a generally positive attitude towards German lessons. Discipline-specific differences in this perception are especially recognizable in students of pharmacy. They would prefer to have a closer interrelation between language and practical topics. These are results of this paper, which examines the motivation of students to learn German as a foreign language at a university in Japan. The basis of this work is the L2 Motivational Self System, which was developed by Zoltán Dörnyei. According to it, the following three components determine the motivation of the foreign language learners: the Ideal L2 Self, the Ought-to L2 Self as well as learning experience in the aspired language. To investigate the changes in motivation during the one year period of learning German, questionnaires have been carried out at two different times: at the beginning and at the end of the learning experience. Furthermore language learning biographies by Riemer have been used to complete the findings. As a consequence of the results, it is explained how to apply Dörnyei’s six-components-plan for the development of an Ideal L2 Self, as well as the work with the European Language Portfolio in German lessons in Japan
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