77 research outputs found
SPR Mikrosensor als universelle Plattform fĂŒr Chemo- und Biosensoren
Die Messung des Brechungsindex mittels der OberflĂ€chenplasmonen-Resonsanz (Surface Plasmon Resonance, kurz: SPR) hat sich im Laufe der letzten Jahre zu einem universellen MeĂprinzip in der chemischen Sensorik sowie der Biosensorik entwickelt. Das Prinzip beruht auf der Anregung von Elektronenschwingungen auf der OberflĂ€che von dĂŒnnen Metallschichten, vielfach Gold oder Silber, durch einfallendes Licht. Das reflektierte Licht wird entweder ĂŒber einen Winkelbereich gemessen oder spektral aufgelöst. Eine MeĂkurve weist ein charakteristisches Minimum auf, dessen Position vom Brechungsindex an der OberflĂ€che der Goldschicht abhĂ€ngt.
Am Max-Planck-Institut fĂŒr marine Mikrobiologie wurde ein faseroptischer Mikrosensor fĂŒr den Brechungsindex auf der Basis von SPR entwickelt. Dieser Sensor findet zunĂ€chst Einsatz in der Charakterisierung der optischen VerhĂ€ltnisse in Sedimenten. Die LichtverhĂ€ltnisse im Sediment sind maĂgeblich fĂŒr die Entwicklung von photosynthetisch aktiven Organismen verantwortlich. Um die Verteilung des Lichts zu messen, ist sowie die Kenntnis der LichtintensitĂ€t als auch die des Brechungsindexes notwendig. Derzeit ist es möglich die LichtintensitĂ€t mit einer Ortsauflösung von 100”m zu messen. Mit dem hier vorgestellten Sensor wird eine prĂ€zise Brechungsindexmessung mit vergleichbarer Ortsauflösung möglich. Desweiteren kann er als Plattform fĂŒr chemische und Biosensoren dienen.
Der hier vorgestellte Sensor ist in der Lage, den Brechungsindex im Bereich von 1.30 bis 1.38 RIU (Refractive Index Units) mit einer Genauigkeit von 10-4 RIU zu messen. HierfĂŒr muĂ eine geeignete sensitive Schicht auf den Sensor aufgebracht werden, die ihren Brechungsindex in Anwesenheit des nachzuweisenden Stoffes Ă€ndert. FĂŒr diese Anwendung bieten sich schwellende, spezifisch bindende Polymere an, die ihre Schichtdicke in AbhĂ€ngigkeit von der Konzentration des nachzuweisenden Stoffes Ă€ndern, wie sie bereits fĂŒr die Messung vonn pH und Metallionenkonzentrationen entwickelt wur
Monitoring Progress of Change: Implementation of Education for Sustainable Development (ESD) within Documents of the German Education System
Education for Sustainable Development (ESD) contributes to a holistic transformation of education systems, fostering deeply rooted learning processes required to co-create a sustainable future for all. The independent project National Monitoring on ESD in Germany traces the status and progress of formal ESD implementation via repeated large-scale indicator-based document analysis. Including over 4500 documents from early childhood education, school education, higher education, and vocational education and training, this study shows that the process of ESD implementation gained momentum over the period of the Global Action Programme (2015–2019). At the same time, large discrepancies remain between the areas of education, different types of documents, federal states, and with regard to the depth and quality of the contextualization of ESD and related concepts. While considerable developments are identifiable within all four formal areas of education, strong additional efforts are required for a comprehensive structural implementation of ESD in Germany. Although the results of the study focus on the status and progress of ESD within the German education system, the methodological framework may also serve as groundwork for other independent, comprehensive, and supportive monitoring programs
Background-free fluorescence decay time sensing and imaging of pH with highly photostable diazaoxotriangulenium dyes
Novel fluorescent diazaoxatriangulenium (DAOTA) pH indicators for lifetime-based self-referenced pH sensing are reported. The DAOTA dyes were decorated with phenolic receptor groups inducing fluorescence quenching via photoinduced electron transfer mechanism. Electron-withdrawing chlorine substituents ensure response in the most relevant pH range (apparent pK'a values ~5 and 7.5 for the p,p-dichlorophenol- and the p-chlorophenol-substituted dyes, respectively). The dyes feature long fluorescence lifetime (17-20 ns), high quantum yield (~60%) and high photostability. Planar optodes are prepared upon immobilization of the dyes into polyurethane hydrogel D4. Apart from the response in the fluorescence intensity, the optodes show pH-dependent lifetime behaviour which makes them suitable for studying 2D pH distribution with help of fluorescence lifetime imaging technique. The lifetime response is particularly pronounced for the sensors with high dye concentration (0.5-1% wt. in respect to the polymer) and is attributed to efficient homo-FRET mechanism
The effects of cerebral oximetry in mechanically ventilated newborns: a protocol for the SafeBoosC-IIIv randomised clinical trial
Background
The SafeBoosC project aims to test the clinical value of non-invasive cerebral oximetry by near-infrared spectroscopy in newborn infants. The purpose is to establish whether cerebral oximetry can be used to save newborn infantsâ lives and brains or not. Newborns contribute heavily to total childhood mortality and neonatal brain damage is the cause of a large part of handicaps such as cerebral palsy. The objective of the SafeBoosC-IIIv trial is to evaluate the benefits and harms of cerebral oximetry added to usual care versus usual care in mechanically ventilated newborns.
Methods/design
SafeBoosC-IIIv is an investigator-initiated, multinational, randomised, pragmatic phase-III clinical trial. The inclusion criteria will be newborns with a gestational age more than 28â+â0Â weeks, postnatal age less than 28Â days, predicted to require mechanical ventilation for at least 24Â h, and prior informed consent from the parents or deferred consent or absence of opt-out. The exclusion criteria will be no available cerebral oximeter, suspicion of or confirmed brain injury or disorder, or congenital heart disease likely to require surgery.
A total of 3000 participants will be randomised in 60 neonatal intensive care units from 16 countries, in a 1:1 allocation ratio to cerebral oximetry versus usual care. Participants in the cerebral oximetry group will undergo cerebral oximetry monitoring during mechanical ventilation in the neonatal intensive care unit for as long as deemed useful by the treating physician or until 28Â days of life. The participants in the cerebral oximetry group will be treated according to the SafeBoosC treatment guideline. Participants in the usual care group will not receive cerebral oximetry and will receive usual care. We use two co-primary outcomes: (1) a composite of death from any cause or moderate to severe neurodevelopmental disability at 2Â years of corrected age and (2) the non-verbal cognitive score of the Parent Report of Childrenâs Abilities-Revised (PARCA-R) at 2Â years of corrected age.
Discussion
There is need for a randomised clinical trial to evaluate cerebral oximetry added to usual care versus usual care in mechanically ventilated newborns.
Trial registration
The protocol is registered at www.clinicaltrials.gov (NCT05907317; registered 18 June 2023)
Rahmenkonzept der Hochschulen des Landes Baden-WĂŒrttemberg fĂŒr datenintensive Dienste â bwDATA Phase III (2020-2024)
Das zentrale Ziel von bwDATA in Phase III ist die optimale UnterstĂŒtzung der Wissenschaft in den Belangen der Datenspeicherung und des nachhaltigen Forschungsdatenmanagements ebenso wie die Versorgung der Landeshochschulen mit auf ihre jeweiligen Belange und BedĂŒrfnisse angepassten Speicherstrukturen und darauf basierenden Diensten. Dem Beispiel des bwHPC-Konzepts folgend werden hierbei enge Abstimmung, Kooperation und Arbeitsteilung zwischen den beteiligten Einrichtungen vertieft.
Das vorliegende Rahmenkonzept soll dabei nicht als absoluter Leitfaden fĂŒr die Periode 2020 bis 2024 dienen, es will vielmehr fĂŒr die verschiedenen Bereiche der Wissenschaft, fĂŒr Forschung, Lehre und Administration die Rahmenbedingungen fĂŒr den koordinierten Aufbau und Betrieb speicherintensiver Dienste definieren. bwDATA basiert dabei auf einer gemeinsamen, strategischen Vorgehensweise aller UniversitĂ€ten, Hochschulen der angewandten Wissenschaften, PĂ€dagogischen Hochschulen, Kunst- und Musikhochschulen, der Dualen Hochschule Baden-WĂŒrttembergs, der Landesbibliotheken und des Landesarchivs.
Ein wesentliches Ziel von bwDATA Phase III ist der verbesserte Umgang mit groĂen wissenschaftlichen Datenmengen ĂŒber den gesamten Data Life Cycle in der BaWĂŒ-Datenföderation und damit auch der verstĂ€rkte Aufbau des Forschungsdatenmanagements fĂŒr die beteiligten wissenschaftlichen Einrichtungen bis hin zu Backup und Langzeitarchivierung.
Das Rahmenkonzept bwDATA definiert die Möglichkeit, die Wissenschaft in den Teilgebieten Forschung, Lehre und Administration durch Verbessern vorhandener und Aufbau neuer Lösungen flexibel zu unterstĂŒtzen
Alternative consent methods used in the multinational, pragmatic, randomised clinical trial SafeBoosC-III
Background
The process of obtaining prior informed consent for experimental treatment does not fit well into the clinical reality of acute and intensive care. The therapeutic window of interventions is often short, which may reduce the validity of the consent and the rate of enrolled participants, to delay trial completion and reduce the external validity of the results. Deferred consent and âopt-outâ are alternative consent methods. The SafeBoosC-III trial was a randomised clinical trial investigating the benefits and harms of cerebral oximetry monitoring in extremely preterm infants during the first 3 days after birth, starting within the first 6 h after birth. Prior, deferred and opt-out consent were all allowed by protocol.
This study aimed to evaluate the use of different consent methods in the SafeBoosC-III trial, Furthermore, we aimed to describe and analyse concerns or complaints that arose during the first 6 months of trial conduct.
Methods
All 70 principal investigators were invited to join this descriptive ancillary study. Each principal investigator received a questionnaire on the use of consent methods in their centre during the SafeBoosC-III trial, including the possibility to describe any concerns related to the consent methods used during the first 6 months of the trial, as raised by the parents or the clinical staff.
Results
Data from 61 centres were available. In 43 centres, only prior informed consent was used: in seven, only deferred consent. No centres used the opt-out method only, but five centres used prior and deferred, five used prior, deferred and opt-out (all possibilities) and one used both deferred and opt-out. Six centres applied to use the opt-out method by their local research ethics committee but were denied using it. One centre applied to use deferred consent but was denied. There were only 23 registered concerns during the execution of the trial.
Conclusions
Consent by opt-out was allowed by the protocol in this multinational trial but only a few investigators opted for it and some research ethics boards did not accept its use. It is likely to need promotion by the clinical research community to unfold its potential
Extremely Preterm Infant Admissions Within the SafeBoosC-III Consortium During the COVID-19 Lockdown
Objective: To evaluate if the number of admitted extremely preterm (EP) infants (born before 28 weeks of gestational age) differed in the neonatal intensive care units (NICUs) of the SafeBoosC-III consortium during the global lockdown when compared to the corresponding time period in 2019. Design: This is a retrospective, observational study. Forty-six out of 79 NICUs (58%) from 17 countries participated. Principal investigators were asked to report the following information: (1) Total number of EP infant admissions to their NICU in the 3 months where the lockdown restrictions were most rigorous during the first phase of the COVID-19 pandemic, (2) Similar EP infant admissions in the corresponding 3 months of 2019, (3) the level of local restrictions during the lockdown period, and (4) the local impact of the COVID-19 lockdown on the everyday life of a pregnant woman. Results: The number of EP infant admissions during the first wave of the COVID-19 pandemic was 428 compared to 457 in the corresponding 3 months in 2019 (â6.6%, 95% CI â18.2 to +7.1%, p = 0.33). There were no statistically significant differences within individual geographic regions and no significant association between the level of lockdown restrictions and difference in the number of EP infant admissions. A post-hoc analysis based on data from the 46 NICUs found a decrease of 10.3%in the total number of NICU admissions (n = 7,499 in 2020 vs. n = 8,362 in 2019). Conclusion: This ad hoc study did not confirm previous reports of a major reduction in the number of extremely pretermbirths during the first phase of the COVID-19 pandemic. Clinical Trial Registration: ClinicalTrial.gov, identifier: NCT04527601 (registered August 26, 2020), https://clinicaltrials.gov/ct2/show/NCT04527601
Psychometric properties of the 7-item game addiction scale among french and German speaking adults
Causes and consequences of liana infestation in southern Amazonia
1. Lianas, a key component of tropical forests, can limit growth of trees, impacting both the structure and functioning of forests, and are expected to benefit from fragmentation and potentially from global climatic changes. While it is critical to understand the impacts of liana infestation on contemporary tropical forests across large geographical areas, to date most liana studies have been focussed on single or few sites.
2. We measured and quantified liana infestation of 16,066 trees with diameter â„10 cm in 27 plots distributed across southern Amazonia, a region characterized by substantial ecological and environmental variation and environmental change. We examined the influence of potential drivers of liana infestation at the plot, species and individual tree level. Additionally, we evaluated the effect of liana infestation on tree growth.
3. More than half of all trees had lianas in their crown. At the plot level, infestation by lianas was driven by forest structure but not by the studied climate or soil fertility variables, though low levels of liana infestation were found in seasonally flooded forests.
4. At the tree level, larger and stouter trees had a greater proportion of their crown infested with lianas. At the species level, trees belonging to intrinsically slowâgrowing, denseâwooded species were more susceptible to liana infestation.
5. Liana infestation had a negative impact on tree growth, with growth of heavily infested trees reduced by 33% compared to nonâinfested. The impact of liana infestation on tree growth was strongest for the bestâlit tree crowns, indicating that lianas act to reduce the large competitive advantage that wellâlit trees otherwise hold over their neighbours.
6. Synthesis. Lianas are a pervasive and influential feature of the extensive forests at the southern edge of Amazonia. The degree of liana infestation in forests was closely linked to speciesâlevel variables such as potential growth and wood density as well as the size of the individual tree. The growth of heavily infested trees was particularly restricted by lianas, and especially so for trees growing in otherwise favourable conditions, indicating the potential for lianas not only to reduce forest growth rates overall, but also to modify competitive hierarchies among trees within tropical forests
Cytisus scoparius (Fam. Fabaceae) in southern Brazil - first step of an invasion process?
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