Reliability study of subsea electronic systems subjected to accelerated thermal cycle ageing

Reliability is of increasing importance for electronics systems operating at harsh environments, such as the electronic telecommunication systems used at subsea level. The aim of this research was to investigate the reliability of such electronic systems through a simulated accelerated thermal cycle test. The paper presents a step-by-step process of designing accelerated thermal cycle test using field operating conditions. The Coffin-Mansion equation was used to calculate the accelerated factor for the thermal cycle test. In order to simulate the expected life time of 25 years, the solder assembly samples were subjected to 400 temperature cycles, with every cycle lasting for 40 minutes. Reliability was determined by measuring shear strengths of solder joints of different electronic components at set intervals. Although some of the components showed an initial decrease in shear strength, it was generally concluded that the electronic assemblies are able to maintain their shear strength for up to 25 years. The fracture surfaces of the solder joints, after shear testing, were also analyzed for brittle and ductile fractures, with the use of scanning electron microscopy (SEM)

Förderung von arbuskulären Mykorrhizapilzen in einer Chenopodiaceae - Mais Fruchtfolge durch Untersaaten

Crops of the families Brassicaceae or Chenopodiaceae are non-host plants for symbiotic arbuscular mycorrhiza fungi (AMF), and thus the AMF infection potential of the soils decreases after cultivation of these crops similar to a fallow. This study aims to sustain the survival of AMF in a fodder beet (non-host) - maize cropping sequence through undersowing of different host and non-host green manure plant species (GMS). Maize served as indicator plant for potential after-effects of the GMS. As expected the AMF green manure hosts were well colonized by AMF (19 to 36%), while AMF structures in roots of the non-host GMS and beet roots were negligible. The fodder beet yield was not affected by the GMS compared to a GMS free control. Forty days after sowing of AMF compatible maize, there was no significant effect of the different GMS from the previous year on maize biomass, plant height and SPAD values (an indirect measure of chlorophyll). At flowering, maize fresh matter was 10% higher in plots previously undersown by AMF compatible GMS, compared to non-host GMS, although AMF root colonisation of maize was similar in all treatments

Metallic conductivity in Na-deficient structural domain walls in the spin-orbit Mott insulator Na2IrO3

Honeycomb Na2IrO3 is a prototype spin-orbit Mott insulator and Kitaev magnet. We report a combined structural and electrical resistivity study of Na2IrO3 single crystals. Laue back-scattering diffraction indicates twinning with ±120◦ rotation around the c∗ axis while scanning electron microscopy displays nanothin lines parallel to all three b-axis orientations of twin domains. Energy dispersive x-ray analysis line scans across such domain walls indicate no change of the Ir signal intensity, i.e., intact honeycomb layers, while the Na intensity is reduced down to ∼2/3 of its original value at the domain walls, implying significant hole doping. Utilizing focused-ion-beam microsectioning, the temperature dependence of the electrical resistance of individual domain walls is studied. It demonstrates the tuning through the metal-insulator transition into a correlated-metal ground state by increasing hole doping

Orchestration of employees\u27 creativity: A phased approach

Digital innovation is a promising but challenging way for established organizations to achieve sustainable competitive advantage. A young research stream focuses on the development of innovations by means of employee involvement, which uses the knowledge and creativity of employees. Although it is clear that employees have been innovation drivers, studies on the roles of knowledge and creativity as foundations of employee-driven innovation are all but absent from the literature. Since not all individuals are equally creative, we investigate, through the analytical lens of the model of creativity and innovation, whether domain knowledge matters or if teams lacking domain knowledge can deliver satisfying results, too. The data collection is based on two design-thinking workshops including interviews, observations, and a survey with domain experts who evaluate the prototypes. Opposing to common assumptions of creativity techniques, domain knowledge is fundamental for developing digital innovations

Zufriedener denn je - Lebensverhältnisse in Deutschland 30 Jahre nach dem Mauerfall

Die Wiedervereinigung Deutschlands jährt sich am 3. Oktober 2020 zum 30. Mal. Drei Jahrzehnte haben gleichwohl noch nicht genügt um die Lebenszufriedenheit zwischen Ost- und Westdeutschen vollkommen anzugleichen. Nach einem kontinuierlichen Schrumpfen des "Happiness Gap" der selbstberichteten Lebenszufriedenheit in den späten 1990ern und frühen 2000er Jahren war der Unterschied im Jahr 2018 zwar geringer denn je, wurde aber nicht vollständig überwunden. Zu diesem Schluss kommt die Analyse, die auf Angaben des Erhebungsjahrs 2018 der Langzeitstudie Sozio-oekonomisches Panel (SOEP) beruht, welche vom DIW Berlin in Zusammenarbeit mit Kantar Public erhoben wird

Comprehensive comparison between azacytidine and decitabine treatment in an acute myeloid leukemia cell line

Azacytidine (AzaC) and decitabine (AzadC) are cytosine analogs that covalently trap DNA methyltransferases, which place the important epigenetic mark 5-methyl-2’-deoxycytidine by methylating 2’-deoxycytidine (dC) at the C5 position. AzaC and AzadC are used in the clinic as antimetabolites to treat myelodysplastic syndrome and acute myeloid leukemia and are explored against other types of cancer. Although their principal mechanism of action is known, the downstream effects of AzaC and AzadC treatment are not well understood and the cellular prerequisites that determine sensitivity toward AzaC and AzadC remain elusive. Here, we investigated the effects and phenotype of AzaC and AzadC exposure on the acute myeloid leukemia cell line MOLM-13. We found that while AzaC and AzadC share many effects on the cellular level, including decreased global DNA methylation, increased formation of DNA double-strand breaks, transcriptional downregulation of important oncogenes and similar changes on the proteome level, AzaC failed in contrast to AzadC to induce apoptosis efficiently in MOLM-13. The only cellular marker that correlated with this clear phenotypical outcome was the level of hydroxy-methyl-dC, an additional epigenetic mark that is placed by TET enzymes and repressed in cancer cells. Whereas AzadC increased hmdC substantially in MOLM-13, AzaC treatment did not result in any increase at all. This suggests that hmdC levels in cancer cells should be monitored as a response toward AzaC and AzadC and considered as a biomarker to judge whether AzaC or AzadC treatment leads to cell death in leukemic cells

Long-term benefit-risk balance of drug-eluting vs. bare-metal stents in daily practice: does stent diameter matter? Three-year follow-up of BASKET

Aims To assess the long-term benefit-risk ratio of drug-eluting (DES) vs. bare-metal stents (BMS) relative to stent size. Methods and results All 826 consecutive BASKET (BAsel Stent Kosten-Effektivitäts Trial) patients randomized 2:1 to DES vs. BMS were followed after 3 years. Data were analysed separately for patients with small stents (<3.0 mm vessel/<4.0 mm bypass grafts, n = 268) vs. only large stents (≥3.0 mm native vessels, n = 558). Clinical events were related to stent thrombosis. Three-year clinical target-vessel revascularization rates remained borderline reduced after DES [9.9 vs. 13.9% (BMS), P = 0.07], particularly in patients with small stents (10.7 vs. 19.8%, P = 0.03; large stents: 9.5 vs. 11.5%, P = 0.44). Cardiac death/myocardial infarction (MI) rates (12.7 vs. 10.0%, P = 0.30) were similar, however, death/MI beyond 6 months was higher after DES [9.1 vs. 3.8% (BMS), P = 0.009], mainly due to increased late death/MI in patients with large stents (9.7 vs. 3.1%, P = 0.006). The results paralleled findings for stent thrombosis. Conclusion The clinical benefit of DES was maintained at no overall increased risk of death or death/MI up to 3 years. However, death/MI rates were increased in DES vs. BMS patients beyond 6 months, particularly in patients with large stents, paralleling findings for stent thrombosis. Thus, stent size seems to influence the 3-year benefit-risk ratio after DES implantatio

PD-1+ natural killer cells in human non-small cell lung cancer can be activated by PD-1/PD-L1 blockade

Natural killer (NK) cells are critically involved in anti-tumor immunity by targeting tumor cells. In this study, we show that intratumoral NK cells from NSCLC patients expressed elevated levels of the immune checkpoint receptor PD-1 on their cell surface. In contrast to the expression of activating receptors, PD-1; +; NK cells co-expressed more inhibitory receptors compared to PD-1; -; NK cells. Intratumoral NK cells were less functional compared to peripheral NK cells, and this dysfunction correlated with PD-1 expression. Tumor cells expressing PD-L1 inhibited the functionality of PD-1; +; NK cells in ex vivo models and induced PD-1 clustering at the immunological synapse between NK cells and tumor cells. Notably, treatment with PD-1 blockade was able to reverse PD-L1-mediated inhibition of PD-1; +; NK cells. Our findings highlight the therapeutic potential of PD-1; +; NK cells in immune checkpoint blockade and could guide the development of NK cell-stimulating agents in combination with PD-1 blockade

Dynamic Resting-State Functional Connectivity in Major Depression

Major depressive disorder (MDD) is characterized by abnormal resting-state functional connectivity (RSFC), especially in medial prefrontal cortical (MPFC) regions of the default network. However, prior research in MDD has not examined dynamic changes in functional connectivity as networks form, interact, and dissolve over time. We compared unmedicated individuals with MDD (n=100) to control participants (n=109) on dynamic RSFC (operationalized as SD in RSFC over a series of sliding windows) of an MPFC seed region during a resting-state functional magnetic resonance imaging scan. Among participants with MDD, we also investigated the relationship between symptom severity and RSFC. Secondary analyses probed the association between dynamic RSFC and rumination. Results showed that individuals with MDD were characterized by decreased dynamic (less variable) RSFC between MPFC and regions of parahippocampal gyrus within the default network, a pattern related to sustained positive connectivity between these regions across sliding windows. In contrast, the MDD group exhibited increased dynamic (more variable) RSFC between MPFC and regions of insula, and higher severity of depression was related to increased dynamic RSFC between MPFC and dorsolateral prefrontal cortex. These patterns of highly variable RSFC were related to greater frequency of strong positive and negative correlations in activity across sliding windows. Secondary analyses indicated that increased dynamic RSFC between MPFC and insula was related to higher levels of recent rumination. These findings provide initial evidence that depression, and ruminative thinking in depression, are related to abnormal patterns of fluctuating communication among brain systems involved in regulating attention and self-referential thinking

Iron-Doped ZnO for Lithium-Ion Anodes: Impact of the Dopant Ratio and Carbon Coating Content

Herein, an investigation of the impact of the dopant and carbon content in iron-doped zinc oxide/carbon composites is presented. For this purpose, a comprehensive morphological, structural, and electrochemical characterization of a series of different compounds is reported, including techniques like X-ray diffraction (XRD), transmission electron microscopy (TEM), inductively coupled plasma optical emission spectroscopy (ICP-OES), thermogravimetric analysis (TGA), specific surface area using the Brunauer-Emmett-Teller (BET) algorithm, pycnometry, small-angle X-ray scattering (SAXS), cyclic voltammetry (CV), and galvanostatic cycling. The obtained results reveal an impact of the iron-dopant content on the crystallite and particle size as well as the detailed de-/lithiation mechanism. The effect on the cycling stability, however, appears to be rather minor. The carbon coating content, on the contrary, has a significant influence on the cycling stability and rate capability. According to these results, a carbon content of about 10 wt% is sufficient to achieve stable cycling at lower current densities, while a carbon content of 15–20 wt% allows for specific capacities of 425–500 mAh g−1, when applying a specific current of 1 A g−1, for instance