142 research outputs found

    Quantum-chemical investigations of reaction mechanisms of enzymes and bioactive molecules

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    Quantum-chemical investigations of reaction mechanisms of enzymes and bioactive molecules

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    Ein Seminarkonzept zur Verbesserung des Wohlbefindens und der Stressbewältigung für Lehramtsstudierende

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    Lehrpersonen sind häufig von psychischen oder psychosomatischen Krankheiten betroffen, die sich durch unspezifische körperliche Symptome wie Erschöpfung und Kopfschmerzen manifestieren. Erste Hinweise auf diese Problematik zeichnen sich aber bereits früher ab: Das Zusammenspiel aus überhöhten Ansprüchen und ungünstigem Zeitmanagement kann das Burnout-Risiko bei angehenden Lehrkräften steigern. Um die Studierenden bei der Bewältigung dieser Herausforderungen besser zu unterstützen, wurde ein innovatives Seminarkonzept entwickelt. Im Seminar sollen Entspannungstechniken, Achtsamkeit und Lernstrategien eingeübt werden, welche durch eine theoretische Fundierung untermauert werden. Darüber hinaus reflektieren Seminarteilnehmer*innen ihre Erfahrungen mit den verschiedenen angebotenen Methoden. Dies dürfte auf Seiten der Studierenden nicht nur zukünftig aufkommenden Stress verringern, sondern auch insgesamt zu einem höheren Wohlbefinden und Studienerfolg beitragen. Das Seminar wird durch eine multimethodische Evaluationsstudie begleitet, in der qualitative und quantitative Befragungen durchgeführt werden. Langfristig soll das Seminar im Curriculum der Lehramtsausbildung etabliert und Lehrkräften zur Verfügung gestellt werden

    Novel insights into biosynthesis and uptake of rhamnolipids and their precursors

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    The human pathogenic bacterium Pseudomonasaeruginosa produces rhamnolipids, glycolipids with functionsfor bacterial motility, biofilm formation, and uptake of hydrophobicsubstrates. Rhamnolipids represent a chemically heterogeneousgroup of secondary metabolites composed of one ortwo rhamnose molecules linked to one or mostly two 3-hydroxyfatty acids of various chain lengths. The biosyntheticpathway involves rhamnosyltransferase I encoded by the rhlABoperon, which synthesizes 3-(3-hydroxyalkanoyloxy)alkanoicacids (HAAs) followed by their coupling to one rhamnose moiety.The resulting mono-rhamnolipids are converted to dirhamnolipidsin a third reaction catalyzed by therhamnosyltransferase II RhlC. However, the mechanism behindthe biosynthesis of rhamnolipids containing only a singlefatty acid is still unknown. To understand the role of proteinsinvolved in rhamnolipid biosynthesis the heterologous expressionof rhl-genes in non-pathogenic Pseudomonas putidaKT2440 strains was used in this study to circumvent the complexquorum sensing regulation in P. aeruginosa. Our resultsreveal that RhlA and RhlB are independently involved inrhamnolipid biosynthesis and not in the form of a RhlAB heterodimercomplex as it has been previously postulated.Furthermore, we demonstrate that mono-rhamnolipids providedextracellularly as well as HAAs as their precursors are generallytaken up into the cell and are subsequently converted todi-rhamnolipids by P. putida and the native host P. aeruginosa.Finally, our results throw light on the biosynthesis ofrhamnolipids containing one fatty acid,which occurs by hydrolyzationof typical rhamnolipids containing two fatty acids,valuable for the production of designer rhamnolipids with desiredphysicochemical properties

    Morphological, agronomical and pharmacological characterization of Hyptis pectinata (L.) Poit germplasm

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    Several species of the genus Hyptis have presented medicinal characteristics and are frequently indicated to treat gastro intestinal infections, gramps and pain, as well as for skin infections. Three harvests were carried out using six H. pectinata accessions, and the following characteristics were evaluated: plant height, canopy diameter, leave length (L) and width (W), L/W relation and dry weight of leaves and stem. The accession SAM006 have presented highest leave dry matter yield when the three harvests were summed. The aqueous leaf extracts of the same six H. pectinata accessions were tested for anti-edematogenic effect using the carrageenin-induced rat paw edema at doses of 200, 400 and 600 mg/kg. The extracts administered orally had a significant anti-edematogenic effect. The dose of 200 mg/kg of accessions SAM004 and SAM005 had a stronger effect reducing the edema by 19.6% and 15.4%, respectively. Similar results were obtained using higher dosages of the aqueous extract of the accessions SAM002, SAM003 and SAM006. It can be concluded that the accessions SAM004, SAM005 and SAM006 are promising genotypes for a plant breeding program that aims the development of a cultivar with highest leave yielding and anti-edematogenic effect

    Factors Associated with Influenza Vaccination of Hospitalized Elderly Patients in Spain

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    Vaccination of the elderly is an important factor in limiting the impact of influenza in the community. The aim of this study was to investigate the factors associated with influenza vaccination coverage in hospitalized patients aged ≥ 65 years hospitalized due to causes unrelated to influenza in Spain. We carried out a cross-sectional study. Bivariate analysis was performed comparing vaccinated and unvaccinated patients, taking in to account sociodemographic variables and medical risk conditions. Multivariate analysis was performed using multilevel regression models. We included 1038 patients: 602 (58%) had received the influenza vaccine in the 2013-14 season. Three or more general practitioner visits (OR = 1.61; 95% CI 1.19-2.18); influenza vaccination in any of the 3 previous seasons (OR = 13.57; 95% CI 9.45-19.48); and 23-valent pneumococcal polysaccharide vaccination (OR = 1.97; 95% CI 1.38-2.80) were associated with receiving the influenza vaccine. Vaccination coverage of hospitalized elderly people is low in Spain and some predisposing characteristics influence vaccination coverage. Healthcare workers should take these characteristics into account and be encouraged to proactively propose influenza vaccination to all patients aged ≥ 65 year

    Multiple sensitive estimation and optimal sample size allocation in the item sum technique

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    For surveys of sensitive issues in life sciences, statistical procedures can be used to reduce nonresponse and social desirability response bias. Both of these phenomena provoke nonsampling errors that are difficult to deal with and can seriously flaw the validity of the analyses. The item sum technique (IST) is a very recent indirect questioning method derived from the item count technique that seeks to procure more reliable responses on quantitative items than direct questioning while preserving respondents' anonymity. This article addresses two important questions concerning the IST: (i) its implementation when two or more sensitive variables are investigated and efficient estimates of their unknown populationmeans are required; (ii) the determination of the optimal sample size to achieve minimum variance estimates. These aspects are of great relevance for survey practitioners engaged in sensitive research and, to the best of our knowledge, were not studied so far. In this article, theoretical results for multiple estimation and optimal allocation are obtained under a generic sampling design and then particularized to simple random sampling and stratified sampling designs. Theoretical considerations are integrated with a number of simulation studies based on data from two real surveys and conducted to ascertain the efficiency gain derived from optimal allocation in different situations. One of the surveys concerns cannabis consumption among university students. Our findings highlight some methodological advances that can be obtained in life sciences IST surveys when optimal allocation is achieved.This work is partially supported by Ministerio de Economía y Competitividad (grant MTM2015-63609-R, Spain), Ministerio de Educación, Cultura y Deporte (grant FPU, Spain), and by the project PRIN-SURWEY (grant 2012F42NS8, Italy)
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