76 research outputs found
Improving Europe's China competence: on the significance of China competence for German and European policy on China
Dealing with China is not only about finding answers to urgent problems in politics, business, or technology. Rather, a system of European China competence must be established that ensures long-term capacity for action. It is crucial to locate this task at the nexus of foreign and education policy. The development of China competence through education should therefore be part of Europe's China strategy. (author's abstract
Template assisted surface micro microstructuring of flowable dental composites and its effect on the microbial adhesion properties
Despite their various advantages, such as good esthetic properties, absence of mercury and adhesive bonding to teeth, modern dental composites still have some drawbacks, e.g., a relatively high rate of secondary caries on teeth filled with composite materials. Recent research suggests that microstructured biomaterials surfaces may reduce microbial adhesion to materials due to unfavorable physical materialâmicrobe interactions. The objectives of this study were, therefore, to test the hypotheses that (i) different surface microstructures can be created on composites by a novel straightforward approach potentially suitable for clinical application and (ii) that these surface structures have a statistically significant effect on microbial adhesion properties.Peer ReviewedPostprint (author's final draft
Mehr Chinakompetenz wagen: zur auĂenpolitischen Bedeutung der Chinakompetenz fĂŒr die deutsche und europĂ€ische Chinapolitik
Bei der Auseinandersetzung mit China geht es nicht nur darum, in Politik, WirtÂschaft oder Technologie Antworten auf drĂ€ngende Probleme zu finden. Vielmehr muss ein System europĂ€ischer Chinakompetenz aufgebaut werden, das langfristige HandlungsfĂ€higkeit sichert. Entscheidend ist, diese Aufgabe an der Schnittstelle von AuĂen- und Bildungspolitik zu verorten. Die Bildung von Chinakompetenz - und Chinakompetenz durch Bildung - sollte daher Teil der europĂ€ischen Chinastrategie sein. (Autorenreferat
Grenzen des transnationalen Wassermanagements am Mekong
Asien gehört zu den vom Klimawandel besonders betroffenen Gebieten: Von den zehn LĂ€ndern, die von 1999 bis 2018 am meisten von Extremwetter geschĂ€digt wurden, liegen sieben in Asien. Sehr schwer getroffen ist derzeit die Mekong-Region, die von einer JahrhundertdĂŒrre geplagt wird. ErnteausfĂ€lle, Nahrungsmittelknappheit und Wassermangel sind nur einige Auswirkungen. VerschĂ€rft werden sie durch den Bau von StaudĂ€mmen am Oberlauf des Mekong, was oft lokale wie zwischenstaatliche KonÂflikte nach sich zieht. Daher ist es notwendig, ein nachhaltiges transnationales WasserÂmanagement fĂŒr den Mekong zu etablieren. Unter dem Gesichtspunkt einer globalen Klimapolitik sollte Deutschland sich weiterhin dafĂŒr engagieren. (Autorenreferat
Improvement of neurovascular imaging using ultra-high-resolution computed tomography angiography
Objective
To evaluate diagnostic image quality of ultra-high-resolution computed tomography angiography (UHR-CTA) in neurovascular imaging as compared to normal resolution CT-angiography (NR-CTA).
Material and Methods
In this retrospective single-center study brain and neck CT-angiography was performed using an ultra-high-resolution computed tomography scanner (nâŻ=â82) or a normal resolution CT scanner (NR-CTA; nâŻ=â73). Ultra-high-resolution images were reconstructed with a 1024âŻĂâ1024 matrix and a slice thickness of 0.25âŻmm, whereas NR-CT images were reconstructed with a 512âŻĂâ512 matrix and a slice thickness of 0.5âŻmm. Three blinded neuroradiologists assessed overall image quality, artifacts, image noise, overall contrast and diagnostic confidence using a 4-point Likert scale. Furthermore, the visualization and delineation of supra-aortic arteries with an emphasis on the visualization of small intracerebral vessels was assessed using a cerebral vascular score, also utilizing a 4-point Likert scale. Quantitative analyses included signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), noise and the steepness of gray value transition. Radiation exposure was determined by comparison of computed tomography dose index (CTDIvol), dose length product (DLP) and mean effective dose. Interrater agreement was evaluated via determining Fleiss-Kappa.
Results
Ultra-high-resolution CT-angiography (UHR-CTA) yielded excellent image quality with superior quantitative (SNR: pâŻ<â0.001, CNR: pâŻ<â0.001, steepness of gray value transition: pâŻ<â0.001) and qualitative results (overall image quality: 4 (Inter quartile range (IQR)âŻ=âŻ4â4); pâŻ<â0.001, diagnostic confidence: 4 (IQRâŻ=âŻ4â4); pâŻ<â0.001) compared to NR-CT (overall image quality: 3 (IQRâŻ=âŻ3â3), diagnostic confidence: 3 (IQRâŻ=âŻ3â4)). Furthermore, UHR-CT enabled significantly superior delineation and visualization of all vascular segments, from proximal extracranial vessels to the smallest peripheral cerebral branches (e.g., UHR-CTA PICA: 4 (3â4) vs. NR-CTA PICA: 3 (2â3); UHR-CTA P4: 4 (IQRâŻ=âŻ3â4) vs. NR-CTA P4: 2 (IQRâŻ=âŻ2â3); UHR-CTA M4: 4 (IQRâŻ=âŻ4â4) vs. NR-CTA M4: 3 (IQRâŻ=âŻ2â3); UHR-CTA A4: 4 (IQRâŻ=âŻ3â4) vs. NR-CTA A4: 2 (IQRâŻ=âŻ2â3); all pâŻ<â0.001). Noteworthy, a reduced mean effective dose was observed when applying UHR-CT (NR-CTA: 1.8âŻÂ±â0.3âŻmSv; UHR-CTA: 1.5âŻÂ±â0.5âŻmSv; pâŻ<â0.001).
Conclusion
Ultra-high-resolution CT-angiography improves image quality in neurovascular imaging allowing the depiction and evaluation of small peripheral cerebral arteries. It may thus improve the detection of pathologies in small cerebrovascular lesions and the resulting diagnosis
Event-related brain potential evidence for animacy processing asymmetries during sentence comprehension
The animacy distinction is deeply rooted in the language faculty. A key example is differential object marking, the phenomenon where animate sentential objects receive specific marking. We used event-related potentials to examine the neural processing consequences of case-marking violations on animate and inanimate direct objects in Spanish. Inanimate objects with incorrect prepositional case marker âaâ (âal sueloâ) elicited a P600 effect compared to unmarked objects, consistent with previous literature. However, animate objects without the required prepositional case marker (âel obispoâ) only elicited an N400 effect compared to marked objects. This novel finding, an exclusive N400 modulation by a straightforward grammatical rule violation, does not follow from extant neurocognitive models of sentence processing, and mirrors unexpected âsemantic P600â effects for thematically problematic sentences. These results may reflect animacy asymmetry in competition for argument prominence: following the article, thematic interpretation difficulties are elicited only by unexpectedly animate objects
Static non-reciprocity in mechanical metamaterials
Reciprocity is a fundamental principle governing various physical systems,
which ensures that the transfer function between any two points in space is
identical, regardless of geometrical or material asymmetries. Breaking this
transmission symmetry offers enhanced control over signal transport, isolation
and source protection. So far, devices that break reciprocity have been mostly
considered in dynamic systems, for electromagnetic, acoustic and mechanical
wave propagation associated with spatio-temporal variations. Here we show that
it is possible to strongly break reciprocity in static systems, realizing
mechanical metamaterials that, by combining large nonlinearities with suitable
geometrical asymmetries, and possibly topological features, exhibit vastly
different output displacements under excitation from different sides, as well
as one-way displacement amplification. In addition to extending non-reciprocity
and isolation to statics, our work sheds new light on the understanding of
energy propagation in non-linear materials with asymmetric crystalline
structures and topological properties, opening avenues for energy absorption,
conversion and harvesting, soft robotics, prosthetics and optomechanics.Comment: 19 pages, 3 figures, Supplementary information (11 pages and 5
figures
RENEB accident simulation exercise
Purpose: The RENEB accident exercise was carried out in order to train the RENEB participants in coordinating and managing potentially large data sets that would be generated in case of a major radiological event.
Materials and methods: Each participant was offered the possibility to activate the network by sending an alerting email about a simulated radiation emergency. The same participant had to collect, compile and report capacity, triage categorization and exposure scenario results obtained from all other participants. The exercise was performed over 27 weeks and involved the network consisting of 28 institutes: 21 RENEB members, four candidates and three non-RENEB partners.
Results: The duration of a single exercise never exceeded 10 days, while the response from the assisting laboratories never came later than within half a day. During each week of the exercise, around 4500 samples were reported by all service laboratories (SL) to be examined and 54 scenarios were coherently estimated by all laboratories (the standard deviation from the mean of all SL answers for a given scenario category and a set of data was not larger than 3 patient codes).
Conclusions: Each participant received training in both the role of a reference laboratory (activating the network) and of a service laboratory (responding to an activation request). The procedures in the case of radiological event were successfully established and tested
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