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Improving the wear and corrosion properties of plasma clad CoCrFeMnNi high entropy alloy coating by low-temperature plasma nitriding
Get PDFCurrent researcher adapted a “surface design strategy” for a high entropy alloy (HEA), with the combination of coating approach to effectively address the high-cost issue of HEAs and surface modification to enhance the surface properties of HEAs. This study systematically investigated the influence of direct current plasma nitriding (DCPN) treatment temperature (430–500 °C) on the microstructure and surface properties of plasma clad CoCrFeMnNi HEA coating through comprehensive microstructure characterization and property evaluation aiming to develop an advanced surface engineering approach for cost-effective and high-performance HEA coatings. The optimal performance was achieved for low-temperature (430 °C and 450 °C) plasma nitrided HEA coatings, where nitrogen-supersaturated S-phase formation resulted in the significant increase in surface hardness, mild abrasive wear and excellent corrosion resistance, demonstrating an ideal balance between mechanical, tribological and chemical properties. On the other hand, as the plasma nitriding temperature increased to 480–500 °C, although hardness was further enhanced through the formation of M3N and CrN precipitation, the combined effects of chromium depletion and brittle phase formation significantly deteriorated the corrosion performance. These findings establish 430 °C and 450 °C as the optimal DCPN treatment temperatures for applications requiring both high wear and corrosion resistance, while higher temperatures (>450 °C) should be avoided due to detrimental phase transformations that compromise surface integrity. The research provides fundamental insights into temperature-dependent microstructure evolution and its impact on surface performance, offering valuable guidance for the optimisation of industrial plasma nitriding processes and open doors to the wide industry application of surface engineered HEA coatings with affordable cost and high-performance.</p
Frond reconstruction of <i>Polymorphopteris mei</i> sp. nov. from the early Permian Wuda Tuff Flora with insights into its taphonomy
Get PDFAncient forests preserved in growth position by rapid sedimentological burial (T0 assemblages) constitute exceptionally valuable fossil repositories, especially those covered by fine-grained volcanic ash (tuff) that may preserve plant morphology and anatomy in high-fidelity. This study documents the frond morphology and anatomy of a new species, Polymorphopteris mei sp. nov. from the Wuda Tuff Flora, an in situ fossil forest Lagerstätte of early Permian age from Inner Mongolia, China preserved by volcanic ash. The frond of P. mei is tripinnate, composed of three types of penultimate pinnae and three types of ultimate pinnae. Anatomical features of the frond and penultimate rachises correspond to the stewartiopterid-type leaf trace configuration characteristic of the Marattiales fern evolutionary stem-group family Psaroniaceae. Pyrite-infilled pore-like structures within the rachises are identified as possible evidence of post-mortem fungal action. This study enhances our understanding of the morphology, anatomy, systematic affinity and taphonomy of P. mei and its ecological context in the early Permian peat-forming communities of Cathaysia.</p
Long-term outcome and predictors for recurrence after medical and interventional treatment of arrhythmias at the UniverSity Heart CenTer Hamburg (TRUST):design and patient profile snapshot of a prospective clinical cohort study
Get PDFAims: Optimal outcomes for patients with cardiac arrhythmias can be achieved through multimodal therapy including lifestyle support, medication, and interventions. Planning of these therapy concepts requires a detailed understanding of phenotypes, responses to therapies, and outcomes. Objective: The prospective Long-term Outcome and Predictors for Recurrence after Medical and Interventional Treatment of Arrhythmias at the University Heart Center Hamburg (TRUST) combines deep phenotypic, procedural, and follow-up information in a contemporary cohort of patients with cardiac arrhythmias. Methods and results: TRUST is an investigator-initiated, prospective, cohort study enrolling consecutive patients at the UHZ Hamburg. Comprehensive baseline work-up, imaging, and biobanking at baseline is combined with follow-up using a combination of in-person visits, online questionnaires, and remote rhythm-monitoring. Enrolment started in March 2021 and is ongoing. This paper describes the design and the clinical characteristics of the first 1500 enrolled patients with verified baseline datasets (562 women (37%), median age 64 (IQR 55, 74) years). Overall, 1077/1500 patients (71%) were seen for atrial fibrillation, 161/1500 (11%) for ventricular tachycardia and premature ventricular complexes, 239/1500 (16%) for supraventricular tachycardia, and 23/1500 (2%) patients for other reasons. Ablations, rhythm surgery, or invasive procedures were performed in 1363/1500 (91%) within 1 month after inclusion. Conclusion: This snapshot of the first 1500 patients enrolled in TRUST illustrates current characteristics and comorbidity burden in patients undergoing arrhythmia treatment. This rich data set will provide information on treatment patterns, detailed phenotypes, and follow-up, offering insights into the natural progression and treatment responses of arrhythmias in routine care
Genomic characterization of Sabiá virus in Brazil, 2019–2020:Implications for diagnostics, virus evolution, and receptor binding
Get PDFBetween December 2019 and January 2020, two patients suspected of having severe yellow fever were admitted to a tertiary healthcare facility in São Paulo, Brazil, presenting with acute hemorrhagic syndrome and neurological alterations; both cases had fatal outcomes. Upon admission, both tested negative for yellow fever viral RNA, and Sabiá virus (SABV), a New World arenavirus, was identified as the causative pathogen. To date, only four humans naturally acquired SABV infections have been confirmed, all fatal and linked to rural settings. We applied next-generation sequencing to generate complete and near-complete genomes from two patients (SP17 and SP19). Existing molecular diagnostics failed to detect SABV; therefore, new molecular tests were developed. Genetic analyses of SP17 and SP19 genomes along with other arenaviruses, revealed that the new cases were genetically diverse, showing 93-98.2% amino acid identity at the NP level among SP17, SP19, and the 1990 reference strain (SPH114202). Time-scaled phylogenetic analyses confirmed that SP17 and SP19 were not epidemiologically linked and suggested that SABV has been circulating undetected in Brazil for over a century. Additionally, homology modeling and structure-based mapping provided insights into SABV receptor-binding sequence conservation, suggesting that SABV shares similar receptor binding structure to other clade B arenaviruses, despite some amino acid variation around receptor binding site. Our findings underscore the need for retrospective and prospective surveillance of undiagnosed hemorrhagic fever cases to assess the public health impact of SABV in Brazil
Closing the denitrification gap:applying the <sup>15</sup>N gas flux method with an artificial atmosphere in conventional and regenerative agriculture
Get PDFIntroduction: Denitrification is an elusive process that remains notoriously difficult to measure under field conditions, yet it plays a crucial role as the only natural terrestrial sink for reactive nitrogen, especially in agricultural systems where large amounts of fertilizer are applied. Direct measurements of N2 fluxes over extended periods remain rare in the literature due to technical challenges. Methods: In this study, we quantified and characterized denitrification emissions under two contrasting land-use practices—conventional and regenerative (unfertilized) agriculture—using a recently developed custom method combining a 15N isotopic tracer with an artificial atmosphere (improved 15N Gas Flux method). We conducted nine field campaigns over one year to (i) assess method applicability, (ii) derive a first annual estimate of denitrification, (iii) understand controls on denitrification dynamics, and (iv) trace denitrification‐driven losses of applied synthetic nitrogen fertilizer in conventional agriculture. Results: Our method successfully detected denitrified N2 fluxes in 90% of measurements and yielded annual budgets of 22.12 and 2.41 kg N ha‐1 yr‐1 in the conventional and regenerative fields, respectively. Soil moisture and nitrate availability (particularly under fertilized conditions) were the main controls on the denitrification product ratio (N2O/(N2O + N2)). We estimated that 11% of applied fertilizer nitrogen was lost via denitrification in the conventional field, with 7.3% of this loss emitted as N2O rather than N2. Discussion: These results underscore the role of fertilization management in shaping denitrification dynamics and its potential to act as a sink for reactive nitrogen, while modulating N2O emissions
Mental health advice on TikTok
Get PDFIn this paper, we provide the first, large-scale corpus-pragmatic analysis of mental health advice by social media influencers on TikTok. We identify advice-giving in large datasets focusing on if-conditionals as a specific form that allows us to analyse how the audience is positioned relative to a need and the solution which is then proposed. To identify the different ways in which mental health issues are presented, we use an adapted version of the ‘mental health quotient’ (Newson and Thiagarajan, 2020), as a linguistically informed framework for differentiating between lay discussions of mental health and those that invoke specific disorders. We sample a corpus of over 27,000 TikTok videos from 85 mental health influencers, using corpus-scale identification to extract and analyse if-conditionals produced by mental health professionals and wellness influencers. Our analysis of the protasis shows how these two types of influencers use prompts that share some similarities but also rely on fundamentally different models of healthcare. The relationship between these prompts and the information and recommendations in the apodosis show how health professionals rely on diagnostic information and therapeutic advice, while wellness influencers recommend embodied practice and products to treat mental health issues. These findings set out the distinctive ecosystem of healthcare which is emerging within the algorithmically driven contexts of sites like TikTok
The biogeography of evolutionary radiations on oceanic archipelagos
Get PDFEvolutionary radiations on oceanic archipelagos (ROAs) have long served as models for understanding evolutionary and ecological processes underlying species diversification. Yet, diversity patterns emerging from ROAs have received relatively little attention from biogeographers, even though characterizing the effect of key geo-environmental factors on island clade species could be important for unraveling diversification dynamics. In this study, we conducted a comparative analysis using island-specific species richness values for approximately one hundred ROAs across major oceanic archipelagos (mostly Hawaii, Canary Islands, Galápagos and Fiji) and taxa (vascular plants, invertebrates and vertebrates). Our aim was to determine whether (1) ROA species richness patterns scale as a function of key geo-environmental factors including island area, geological age, environmental heterogeneity (elevation and topographic complexity) and inter-island isolation, and (2) whether the magnitude of the effects of these factors varies across archipelagos and taxa. Our results identified elevation as a key driver of ROA species richness patterns on islands, supporting existing theoretical and empirical work that highlighted the central role of environmental heterogeneity in driving diversification on oceanic islands. As importantly, we found that the influence of geo-environmental factors varies across archipelagos and taxa, suggesting that unique archipelagic dynamics and biological traits together shape diversification differently. Our findings emphasize the value of applying biogeographical modeling at the resolution of individual radiations to improve our understanding of evolutionary processes on oceanic archipelagos
Evaluation and Management of Thyroid Nodules:A Joint Consensus Statement From the British Thyroid Association (BTA), British Association of Endocrine and Thyroid Surgeons (BAETS) and Collaborating Bodies
Get PDFThe Microbiome of an Invasive Antarctic insect, <i>Eretmoptera Murphyi</i> (Diptera: Chironomidae), and its Potential Role in Nutrient Cycling
Get PDFEretmoptera murphyi Schaeffer 1914 is a flightless chironomid midge endemic to South Georgia in the sub-Antarctic. In the 1960s it was accidentally introduced to Signy Island (in the more extreme maritime Antarctic), where it is now considered an invasive species. Detritivorous E. murphyi larvae can increase soil nitrogen levels by up to five times compared with similar uncolonized substrates, although the mechanisms involved remain unknown. This study conducted the first larval microbiome characterisation of E. murphyi, with the aim of identifying groups of microorganisms that may contribute to the elevated nutrient availability associated with this species. We also compare the E. murphyi microbiome with information available for other Antarctic invertebrates. Dominant archaea and bacteria included Crenarchaeota, Actinobacteriota, Chloroflexi, Proteobacteria and Planctomycetota, many of which have known roles in nutrient cycling. The microbiome of E. murphyi appears more diverse than that of other Antarctic invertebrates studied to date and includes phyla (Chloroflexi and Mycococcota) not previously reported from Signy Island soils or other Antarctic terrestrial invertebrate species. Further research is needed to establish which of these taxa represent true endosymbionts and to confirm their functional roles. The impact of non-native species microbiomes on nutrient cycling has important implications for polar terrestrial ecosystems, as significant changes in nutrient availability could impact native microarthropod and plant communities, as well as open new pathways for future non-native species establishment
Exploring the Life Journeys of Gang-Involved Youth and Their Experiences of Social Support with Gang-Involved Peers
Get PDFGang-involved youth face heightened risks of violence, yet little research has explored how they understand these experiences, particularly in relation to peer relationships and support within gangs. This study used Interpretative Phenomenological Analysis to analyse data from semi-structured interviews with five young males with gang involvement. Three superordinate themes were identified: For me, it’s just how life was; The gang and I: A sense of belonging; and Finding a new path. Participants described involvement as shaped by early circumstances, identity and connection needs, and shifting perspectives over time. Findings highlight the complex role of gangs as both supportive and harmful
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