81 research outputs found
AMONTRACK â Ein EU gef\uf6rdertes Projekt zur automatisierten Detektion von Einzelfehlern auf der Schienenfahrfl\ue4che
Initial interaction of citrate-coated iron oxide nanoparticles with the glycocalyx of THP-1 monocytes assessed by real-time magnetic particle spectroscopy and electron microscopy
Interaction with biological material can alter physicochemical parameters of magnetic nanoparticles and might thereby change their magnetic behavior with potentially important implications for various nanoparticle applications. Little is known about changes of the magnetic behavior that occur during the initial phase of cell binding and uptake. We investigate the magnetic behavior of very small superparamagnetic iron-oxide nanoparticles (VSOP) during initial contact with THP-1 monocytes. We combine real-time magnetic particle spectroscopy (MPS), a fast and sensitive method for specific detection of magnetic nanoparticles in biological specimen with high-pressure-freezing/freeze-substitution transmission electron microscopy (HPF/FS-TEM), enabling us to generate snapshots of the interaction of VSOP with the cellular glycocalyx. MPS reveals significant changes of the dynamic magnetic behavior within seconds after VSOP injection into monocyte suspensions that correlate with the formation of nanoparticle clusters in the glycocalyx. The combination of real-time MPS and HPF/FS-TEM provides an ideal platform to analyze magnetic behaviors of nanoparticles upon interaction with cells and tissues
Acoustic monitoring of rail faults in the German railway network
The early detection of rail surface defects such as squats, poor welds, or wheel burns is important to prevent further rail deterioration. In this paper, a methodology for acoustic monitoring of squats in the German railway network is proposed based on the measurement of axle box acceleration (ABA) on the DB noise measurement car (SMW) and the previously developed numerical model WERAN for wheel/rail interaction. Specific characteristics of squats in the ABA signals are determined with the model and verified by pass-by measurements combined with direct geometry measurements of the squats. Based on these re- sults, a logistic regression classifier is devised for the detection of squats in the measured ABA signals of the SMW. Trained with simulated and measured data, the classifier identifies all of the known severe squats and 87% of the known light squats in the measured test data
Sequential effects in continued visual search: Using fixation-related potentials to compare distractor processing before and after target detection
To search for a target in a complex environment is an everyday behavior that ends with finding the target. When we search for two identical targets, however, we must continue the search after finding the first target and memorize its location. We used fixation-related potentials to investigate the neural correlates of different stages of the search, that is, before and after finding the first target. Having found the first target influenced subsequent distractor processing. Compared to distractor fixations before the first target fixation, a negative shift was observed for three subsequent distractor fixations. These results suggest that processing a target in continued search modulates the brain's response, either transiently by reflecting temporary working memory processes or permanently by reflecting working memory retention
Vegan Diet and Bone HealthâResults from the Cross-Sectional RBVD Study
Scientific evidence suggests that a vegan diet might be associated with impaired bone
health. Therefore, a cross-sectional study (n = 36 vegans, n = 36 omnivores) was used to investigate the
associations of veganism with calcaneal quantitative ultrasound (QUS) measurements, along with the
investigation of differences in the concentrations of nutrition- and bone-related biomarkers between
vegans and omnivores. This study revealed lower levels in the QUS parameters in vegans compared
to omnivores, e.g., broadband ultrasound attenuation (vegans: 111.8 ± 10.7 dB/MHz, omnivores:
118.0 ± 10.8 dB/MHz, p = 0.02). Vegans had lower levels of vitamin A, B2, lysine, zinc, selenoprotein
P, n-3 fatty acids, urinary iodine, and calcium levels, while the concentrations of vitamin K1, folate,
and glutamine were higher in vegans compared to omnivores. Applying a reduced rank regression,
12 out of the 28 biomarkers were identified to contribute most to bone health, i.e., lysine, urinary
iodine, thyroid-stimulating hormone, selenoprotein P, vitamin A, leucine, α-klotho, n-3 fatty acids,
urinary calcium/magnesium, vitamin B6, and FGF23. All QUS parameters increased across the
tertiles of the pattern score. The study provides evidence of lower bone health in vegans compared
to omnivores, additionally revealing a combination of nutrition-related biomarkers, which may
contribute to bone health. Further studies are needed to confirm these findings
Vegan Diet and Bone HealthâResults from the Cross-Sectional RBVD Study
Scientific evidence suggests that a vegan diet might be associated with impaired bone
health. Therefore, a cross-sectional study (n = 36 vegans, n = 36 omnivores) was used to investigate the
associations of veganism with calcaneal quantitative ultrasound (QUS) measurements, along with the
investigation of differences in the concentrations of nutrition- and bone-related biomarkers between
vegans and omnivores. This study revealed lower levels in the QUS parameters in vegans compared
to omnivores, e.g., broadband ultrasound attenuation (vegans: 111.8 ± 10.7 dB/MHz, omnivores:
118.0 ± 10.8 dB/MHz, p = 0.02). Vegans had lower levels of vitamin A, B2, lysine, zinc, selenoprotein
P, n-3 fatty acids, urinary iodine, and calcium levels, while the concentrations of vitamin K1, folate,
and glutamine were higher in vegans compared to omnivores. Applying a reduced rank regression,
12 out of the 28 biomarkers were identified to contribute most to bone health, i.e., lysine, urinary
iodine, thyroid-stimulating hormone, selenoprotein P, vitamin A, leucine, α-klotho, n-3 fatty acids,
urinary calcium/magnesium, vitamin B6, and FGF23. All QUS parameters increased across the
tertiles of the pattern score. The study provides evidence of lower bone health in vegans compared
to omnivores, additionally revealing a combination of nutrition-related biomarkers, which may
contribute to bone health. Further studies are needed to confirm these findings
Venous lactate improves the prediction of in-hospital adverse outcomes in normotensive pulmonary embolism
Background: Arterial lactate is an established risk marker in patients with pulmonary embolism (PE). However, its clinical applicability is limited by the need of an arterial puncture. In contrast, venous lactate can easily be measured from blood samples obtained via routine peripheral venepuncture. Methods: We investigated the prognostic value of venous lactate with regard to in-hospital adverse outcomes and mortality in 419 consecutive PE patients enrolled in a single-center registry between 09/2008 and 09/2017. Results: An optimised venous lactate cut-off value of 3.3 mmol/l predicted both, in-hospital adverse outcome (OR 11.0 [95% CI 4.6?26.3]) and all-cause mortality (OR 3.8 [95%CI 1.3?11.3]). The established cut-off value for arterial lactate (2.0 mmol/l) and the upper limit of normal for venous lactate (2.3 mmol/l) had lower prognostic value for adverse outcomes (OR 3.6 [95% CI 1.5?8.7] and 5.7 [95% CI 2.4?13.6], respectively) and did not predict mortality. If added to the 2019 European Society of Cardiology (ESC) algorithm, venous lactate Conclusion: Venous lactate above the upper limit of normal was associated with increased risk for adverse outcomes and an optimised cut-off value of 3.3 mmol/l predicted adverse outcome and mortality. Adding venous lactate to the 2019 ESC algorithm may improve risk stratification. Importantly, the established cut-off value for arterial lactate has limited specificity in venous samples and should not be used.Peer reviewe
The biological controls of soil carbon accumulation following wildfire and harvest in boreal forests: A review
Boreal forests are frequently subjected to disturbances, including wildfire and clear-cutting. While these disturbances can cause soil carbon (C) losses, the long-term accumulation dynamics of soil C stocks during subsequent stand development is controlled by biological processes related to the balance of net primary production (NPP) and outputs via heterotrophic respiration and leaching, many of which remain poorly understood. We review the biological processes suggested to influence soil C accumulation in boreal forests. Our review indicates that median C accumulation rates following wildfire and clear-cutting are similar (0.15 and 0.20 Mg ha(-1) year(-1), respectively), however, variation between studies is extremely high. Further, while many individual studies show linear increases in soil C stocks through time after disturbance, there are indications that C stock recovery is fastest early to mid-succession (e.g. 15-80 years) and then slows as forests mature (e.g. >100 years). We indicate that the rapid build-up of soil C in younger stands appears not only driven by higher plant production, but also by a high rate of mycorrhizal hyphal production, and mycorrhizal suppression of saprotrophs. As stands mature, the balance between reductions in plant and mycorrhizal production, increasing plant litter recalcitrance, and ectomycorrhizal decomposers and saprotrophs have been highlighted as key controls on soil C accumulation rates. While some of these controls appear well understood (e.g. temporal patterns in NPP, changes in aboveground litter quality), many others remain research frontiers. Notably, very little data exists describing and comparing successional patterns of root production, mycorrhizal functional traits, mycorrhizal-saprotroph interactions, or C outputs via heterotrophic respiration and dissolved organic C following different disturbances. We argue that these less frequently described controls require attention, as they will be key not only for understanding ecosystem C balances, but also for representing these dynamics more accurately in soil organic C and Earth system models
Estimating canopy gross primary production by combining phloem stable isotopes with canopy and mesophyll conductances
Gross primary production (GPP) is a key component of the forest carbon cycle. However, our knowledge of GPP at the stand scale remains uncertain, because estimates derived from eddy covariance (EC) rely on semi-empirical modelling and the assumptions of the EC technique are sometimes not fully met. We propose using the sap flux/isotope method as an alternative way to estimate canopy GPP, termed GPP(iso/SF), at the stand scale and at daily resolution. It is based on canopy conductance inferred from sap flux and intrinsic water-use efficiency estimated from the stable carbon isotope composition of phloem contents. The GPP(iso/SF)estimate was further corrected for seasonal variations in photosynthetic capacity and mesophyll conductance. We compared our estimate of GPP(iso/SF)to the GPP derived from PRELES, a model parameterized with EC data. The comparisons were performed in a highly instrumented, boreal Scots pine forest in northern Sweden, including a nitrogen fertilized and a reference plot. The resulting annual and daily GPP(iso/SF)estimates agreed well with PRELES, in the fertilized plot and the reference plot. We discuss the GPP(iso/SF)method as an alternative which can be widely applied without terrain restrictions, where the assumptions of EC are not met.Peer reviewe
Review on Superconducting Materials
Short review of the topical comprehension of the superconductor materials
classes Cuprate High-Temperature Superconductors, other oxide superconductors,
Iron-based Superconductors, Heavy-Fermion Superconductors, Nitride
Superconductors, Organic and other Carbon-based Superconductors and Boride and
Borocarbide Superconductors, featuring their present theoretical understanding
and their aspects with respect to technical applications.Comment: A previous version of this article has been published in \" Applied
Superconductivity: Handbook on Devices and Applications \", Wiley-VCH ISBN:
978-3-527-41209-9. The new extended and updated version will be published in
\" Encyclopedia of Applied Physics \", Wiley-VC
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