174 research outputs found
Continuous 25-yr aerosol records at coastal Antarctica: Part 2: Variability of the radionuclides 7Be, 10Be 210Pb
We investigated the variability of210Pb,7Be10Be in coastal Antarctic aerosol samples based on continuous, monthly annually resolved time series obtained from Neumayer Station over the period 1983 to 2008. Clear seasonal cycles peaking in the local summe
A Circular Economy Strategy Selection Approach: Component-based Strategy Assignment using the Example of Electric Motors
The sustainability of industrial processes and products is a core issue of our time. There are several approaches to move from a linear, inherently wasteful economic principle to a circular economy focused on conserving products, resources, and energy. However, selecting which of the circular economy strategies ranging from reuse, repurpose, and remanufacture to recycling is crucial to ensure the economic viability of the product. This contribution proposes an iterative, component-based circular economy strategy selection method that supports product and production planners in choosing the appropriate circular economy strategy. For this approach, the suitability of each component for circular economy strategies is assessed based on identified key properties. In case of no fitting strategy, further component decomposition is devised, and the process is repeated. To further support the design of circular economy strategies, a modular process build set is suggested, enabling the swift composition of the processing sequence. The approach is then applied to the example of an electric motor of a battery electric vehicle. The presented approach allows a quick first assessment of the viability of different circular economy strategies and helps product and production engineers develop product-specific circular economy strategies
A Circular Economy Strategy Selection Approach: Component-based Strategy Assignment using the Example of Electric Motors
The sustainability of industrial processes and products is a core issue of our time. There are several approaches to move from a linear, inherently wasteful economic principle to a circular economy focused on conserving products, resources, and energy. However, selecting which of the circular economy strategies ranging from reuse, repurpose, and remanufacture to recycling is crucial to ensure the economic viability of the product. This contribution proposes an iterative, component-based circular economy strategy selection method that supports product and production planners in choosing the appropriate circular economy strategy. For this approach, the suitability of each component for circular economy strategies is assessed based on identified key properties. In case of no fitting strategy, further component decomposition is devised, and the process is repeated. To further support the design of circular economy strategies, a modular process build set is suggested, enabling the swift composition of the processing sequence. The approach is then applied to the example of an electric motor of a battery electric vehicle. The presented approach allows a quick first assessment of the viability of different circular economy strategies and helps product and production engineers develop product-specific circular economy strategies
A p38MAPK/MK2 signaling pathway leading to redox stress, cell death and ischemia/reperfusion injury
Background
Many diseases and pathological conditions are characterized by transient or constitutive overproduction of reactive oxygen species (ROS). ROS are causal for ischemia/reperfusion (IR)-associated tissue injury (IRI), a major contributor to organ dysfunction or failure. Preventing IRI with antioxidants failed in the clinic, most likely due to the difficulty to timely and efficiently target them to the site of ROS production and action. IR is also characterized by changes in the activity of intracellular signaling molecules including the stress kinase p38MAPK. While ROS can cause the activation of p38MAPK, we recently obtained in vitro evidence that p38MAPK activation is responsible for elevated mitochondrial ROS levels, thus suggesting a role for p38MAPK upstream of ROS and their damaging effects.<p></p>
Results
Here we identified p38MAPKα as the predominantly expressed isoform in HL-1 cardiomyocytes and siRNA-mediated knockdown demonstrated the pro-oxidant role of p38MAPKα signaling. Moreover, the knockout of the p38MAPK effector MAPKAP kinase 2 (MK2) reproduced the effect of inhibiting or knocking down p38MAPK. To translate these findings into a setting closer to the clinic a stringent kidney clamping model was used. p38MAPK activity increased upon reperfusion and p38MAPK inhibition by the inhibitor BIRB796 almost completely prevented severe functional impairment caused by IR. Histological and molecular analyses showed that protection resulted from decreased redox stress and apoptotic cell death.<p></p>
Conclusions
These data highlight a novel and important mechanism for p38MAPK to cause IRI and suggest it as a potential therapeutic target for prevention of tissue injury.<p></p>
Oxidation of Monolignols by Members of the Berberine Bridge Enzyme Family Suggests a Role in Plant Cell Wall Metabolism
Plant genomes contain a large number of genes encoding for berberine bridge enzyme (BBE)-like enzymes. Despite the widespread occurrence and abundance of this protein family in the plant kingdom, the biochemical function remains largely unexplored. In this study, we have expressed two members of the BBE-like enzyme family from Arabidopsis thaliana in the host organism Komagataella pastoris. The two proteins, termed AtBBE-like 13 and AtBBE-like 15, were purified, and their catalytic properties were determined. In addition, AtBBE-like 15 was crystallized and structurally characterized by x-ray crystallography. Here, we show that the enzymes catalyze the oxidation of aromatic allylic alcohols, such as coumaryl, sinapyl, and coniferyl alcohol, to the corresponding aldehydes and that AtBBE-like 15 adopts the same fold as vanillyl alcohol oxidase as reported previously for berberine bridge enzyme and other FAD-dependent oxidoreductases. Further analysis of the substrate range identified coniferin, the glycosylated storage form of coniferyl alcohol, as a substrate of the enzymes, whereas other glycosylated monolignols were rather poor substrates. A detailed analysis of the motifs present in the active sites of the BBE-like enzymes in A. thaliana suggested that 14 out of 28 members of the family might catalyze similar reactions. Based on these findings, we propose a novel role of BBE-like enzymes in monolignol metabolism that was previously not recognized for this enzyme family
A remote sensing-guided forest inventory concept using multispectral 3D and height information from ZiYuan-3 satellite data
Increased frequencies of storms and droughts due to climate change are changing central European forestsmore rapidly than in previous decades. To monitor these changes, multispectral 3D remote sensing (RS) data canprovide relevant information for forest management and inventory. In this case study, data of the multispectral3D-capable satellite system ZiYuan-3 (ZY-3) were used in a RS-guided forest inventory concept to reduce the fieldsample size compared to the standard grid inventory. We first pre-stratified the forest area via the ZY-3 datasetinto coniferous, broadleaved and mixed forest types using object-based image analysis. Each forest type wasthen split into three height strata using the ZY-3 stereo module-derived digital canopy height model (CHM).Due to limited sample sizes, we reduced the nine to six strata. Then, for each of the six strata, we randomlyselected representative segments for inventory plot placement. We then conducted field inventories in theseplots. The collected field data were used to calculate forest attributes, such as tree species composition, timbervolume and canopy height at plot level (terrestrially measured tree height and height information from ZY-3CHM).Subsequently,wecomparedtheresultingforestattributesfromtheRS-guidedinventorywiththereferencedata from a grid inventory based only on field plots. The difference in mean timber volumes to the reference was+30.21 m3ha−1(8.99 per cent) for the RS-guided inventory with terrestrial height and−11.32 m3ha−1(−3.37per cent) with height information from ZY-3 data. The relative efficiency (RE) indicator was used to comparethe different sampling schemes. The RE as compared to a random reduction of the sample size was 1.22 forthe RS-guided inventory with terrestrial height measurements and 1.85 with height information from ZY-3 data.The results show that the presented workflow based on 3D ZY-3 data is suitable to support forest inventories byreducing the sample size and hence potentially increase the inventory frequency
Effects of Short Term Adiponectin Receptor Agonism on Cardiac Function and Energetics in Diabetic db/db Mice.
Objective
Impaired cardiac efficiency is a hallmark of diabetic cardiomyopathy in models of type 2 diabetes. Adiponectin receptor 1 (AdipoR1) deficiency impairs cardiac efficiency in non-diabetic mice, suggesting that hypoadiponectinemia in type 2 diabetes may contribute to impaired cardiac efficiency due to compromised AdipoR1 signaling. Thus, we investigated whether targeting cardiac adiponectin receptors may improve cardiac function and energetics, and attenuate diabetic cardiomyopathy in type 2 diabetic mice.
Methods
A non-selective adiponectin receptor agonist, AdipoRon, and vehicle were injected intraperitoneally into Eight-week-old db/db or C57BLKS/J mice for 10 days. Cardiac morphology and function were evaluated by echocardiography and working heart perfusions.
Results
Based on echocardiography, AdipoRon treatment did not alter ejection fraction, left ventricular diameters or left ventricular wall thickness in db/db mice compared to vehicle-treated mice. In isolated working hearts, an impairment in cardiac output and efficiency in db/db mice was not improved by AdipoRon. Mitochondrial respiratory capacity, respiration in the presence of oligomycin, and 4-hydroxynonenal levels were similar among all groups. However, AdipoRon induced a marked shift in the substrate oxidation pattern in db/db mice towards increased reliance on glucose utilization. In parallel, the diabetes-associated increase in serum triglyceride levels in vehicle-treated db/db mice was blunted by AdipoRon treatment, while an increase in myocardial triglycerides in vehicle-treated db/db mice was not altered by AdipoRon treatment.
Conclusion
AdipoRon treatment shifts myocardial substrate preference towards increased glucose utilization, likely by decreasing fatty acid delivery to the heart, but was not sufficient to improve cardiac output and efficiency in db/db mice
Tachycardiomyopathy entails a dysfunctional pattern of interrelated mitochondrial functions
Tachycardiomyopathy is characterised by reversible left ventricular dysfunction, provoked by rapid ventricular rate. While the knowledge of mitochondria advanced in most cardiomyopathies, mitochondrial functions await elucidation in tachycardiomyopathy. Pacemakers were implanted in 61 rabbits. Tachypacing was performed with 330 bpm for 10 days (n = 11, early left ventricular dysfunction) or with up to 380 bpm over 30 days (n = 24, tachycardiomyopathy, TCM). In n = 26, pacemakers remained inactive (SHAM). Left ventricular tissue was subjected to respirometry, metabolomics and acetylomics. Results were assessed for translational relevance using a human-based model: induced pluripotent stem cell derived cardiomyocytes underwent field stimulation for 7 days (TACH–iPSC–CM). TCM animals showed systolic dysfunction compared to SHAM (fractional shortening 37.8 ± 1.0% vs. 21.9 ± 1.2%, SHAM vs. TCM, p < 0.0001). Histology revealed cardiomyocyte hypertrophy (cross-sectional area 393.2 ± 14.5 µm2 vs. 538.9 ± 23.8 µm2, p < 0.001) without fibrosis. Mitochondria were shifted to the intercalated discs and enlarged. Mitochondrial membrane potential remained stable in TCM. The metabolite profiles of ELVD and TCM were characterised by profound depletion of tricarboxylic acid cycle intermediates. Redox balance was shifted towards a more oxidised state (ratio of reduced to oxidised nicotinamide adenine dinucleotide 10.5 ± 2.1 vs. 4.0 ± 0.8, p < 0.01). The mitochondrial acetylome remained largely unchanged. Neither TCM nor TACH–iPSC–CM showed relevantly increased levels of reactive oxygen species. Oxidative phosphorylation capacity of TCM decreased modestly in skinned fibres (168.9 ± 11.2 vs. 124.6 ± 11.45 pmol·O2·s−1·mg−1 tissue, p < 0.05), but it did not in isolated mitochondria. The pattern of mitochondrial dysfunctions detected in two models of tachycardiomyopathy diverges from previously published characteristic signs of other heart failure aetiologies
Expression of pH-Sensitive TRPC4 in Common Skin Tumors
TRPCs (transient receptor potential classical or cation channels) play a crucial role in tumor biology, especially in the Ca2+ homeostasis in cancer cells. TRPC4 is a pH-sensitive member of this family of proteins. As solid tumors exhibit an inversed pH-gradient with lowered extracellular and increased intracellular pH, both contributing to tumor progression, TRPC4 might be a signaling molecule in the altered tumor microenvironment. This is the first study to investigate the expression profiles of TRPC4 in common skin cancers such as basal cell carcinoma (BCC), squamous cell carcinoma (SCC), malignant melanoma (MM) and nevus cell nevi (NCN). We found that all SCCs, NCNs, and MMs show positive TRPC4-expression, while BCCs do only in about half of the analyzed samples. These data render TRPC4 an immunohistochemical marker to distinguish SCC and BCC, and this also gives rise to future studies investigating the role of TRPC4 in tumor progression, and especially metastasis as BCCs very rarely spread and are mostly negative for TRPC4
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