Measuring the fracture energy of WC grain boundaries

Cemented carbide (WC-Co) is a composite with tungsten carbide particles embedded in a cobalt matrix1. Applications in mining, drilling and metal cutting industries makes use of WC-Co composed materials owing to its high hardness and wear resistance2,3. WC-Co tools undergo wear and fracture over their lifetime leading to degradation in performance and eventual failure. Hence, it is beneficial to build up knowledge of wear and fracture of WC-Co. This work is aimed at exploring the fracture component. The objective of the study is to investigate the fracture energy of different interfaces within the structure. This will be achieved through performing double cantilever beam (DCB) tests at carbide grain boundaries of interest and results will be compared with DFT calculations. Electron backscattered diffraction (EBSD) has been employed to choose single grains or boundaries of interest. MTEX has been employed to process the EBSD data and allow boundaries that are of the correct type and perpendicular to the surface to be chosen. Finally, DCBs have been fabricated within regions of interest and tests have been performed to study interface properties. References 1. Srinivasan M, Rafaniello W. Non-oxide materials: Applications and engineering. In: Carbide, nitride and boride materials synthesis and processing. Springer; 1997:3-42. 2. Lenel FV. Powder metallurgy: Principles and applications. Metal Powder Industry; 1980. 3. Krebs RE. Transition elements: Metals to nonmetals. In: The history and use of our earth\u27s chemical elements: A reference guide. Greenwood Publishing Group; 2006:154

Using coupled micropillar compression and micro-Laue diffraction to investigate deformation mechanisms in a complex metallic alloy Al13Co4

In this investigation, we have used in-situ micro-Laue diffraction combined with micropillar compression of focused ion beam milled Al13Co4 complex metallic alloy to study the evolution of deformation in Al13Co4. Streaking of the Laue spots showed that the onset of plastic flow occured at stresses as low as 0.8 GPa, although macroscopic yield only becomes apparent at 2 GPa. The measured misorientations, obtained from peak splitting, enabled the geometrically necessary dislocation density to be estimated as 1.1 x 1013 m-2

Analysis of predictive factors influencing dupilumab continuation rate in adult patients with atopic dermatitis. results from an italian multicenter study

Objectives: The purpose of this study was to analyze the drug survival rate of dupilumab up to 2 years in a large real-world cohort of adult patients affected by moderate/severe atopic dermatitis (AD), and to investigate the clinical, demographic and predictive factors influencing the patients’ treatment persistence. Material and methods: This study included adult patients affected by moderate-to-severe AD treated with dupilumab for at least 16 weeks who visited 7 dermatologic outpatient clinics in Lazio, Italy, from January 2019 until August 2021. Results: A total of 659 adult patients (345 male [52.3%], mean age: 42.8 years) with an average treatment duration of 23.3 months were enrolled in the study. Overall, 88.6% and 76.1% of patients were still on treatment after 12 and 24 months, respectively. The drug survival rate for discontinuation due to AEs and dupilumab ineffectiveness was 95.0% at 12 months and 90.0% at 24 months. The main reasons for drug discontinuation included inefficacy (29.6%), failed compliance (17.4%), persistent efficacy (20.4%) and adverse events (7.8%). Adult AD onset (≥18 years) and EASI score severity measured at the last follow-up visit were the only factors significantly associated with lower drug survival. Conclusion: This study revealed an increased cumulative probability of dupilumab survival at 2 years, reflected by a sustained effectiveness and a favorable safety profile of the drug

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Local strain rate sensitivity of single α phase within a dual-phase Ti alloy

We have performed in-situ micropillar compression to investigate the local strain rate sensitivity of single α phase in dual-phase Ti alloy, Ti-6Al-2Sn-4Zr-2Mo (wt%). Electron backscatter diffraction (EBSD) was used to identify two grains, anticipated to primarily activate 〈a〉 slip on the basal and prismatic plane respectively. Comparative micropillars were fabricated within single α laths and load-hold tests were conducted with variable strain rates (on the order of 10-2 to 10-4s-1). Local strain rate sensitivity exponent (i.e. m value) is determined using two types of methods, constant strain rate method (CSRM) and conventional stress relaxation method (SRM), showing similar rate sensitivity trends but one order higher magnitude in SRM. We thus propose a new approach to analyse the SRM data, resulting in satisfactory agreement with the CSRM. Significant slip system dependent rate sensitivity is observed such that the prism slip has a strikingly higher m value than the basal. Fundamental mechanisms differing the rate sensitivity are discussed with regards to dislocation plasticity, where more resistance to move dislocations and hence higher hardening gradients are found in the basal slip. The impact of this finding for dwell fatigue deformation modes and the effectiveness of the present methodology for screening new alloy designs are discussed

Effects of dupilumab in type 1 neurofibromatosis coexisting with severe atopic dermatitis

Neurofibromatosis type 1 still lacks established treatment options aimed at controlling the progression of neurofibromas as well as effective therapy for the neurogenic itch associated with the disease. We report the case of a 30-year-old Caucasian woman with type 1 neurofibromatosis coexisting with severe refractory atopic dermatitis. Dupilumab, a novel anti-IL-4 receptor alpha monoclonal antibody, the first biologic agent approved for atopic dermatitis, was the drug of choice in this case. We observed remission of atopic dermatitis and a remarkable reduction in the size and swelling of neurofibromas and in the related pruritus, that became evident after one month of treatment. After 18 months of therapy, no new neurofibromas were detected and preexistent lesions showed no increase in size. These findings are consistent with the hypothesis that dupilumab, a potent anti-inflammatory drug, may have a positive effect on type 1 neurofibromatosis by stopping the progression of preexisting neurofibromas and the onset of new lesions

“Brick-and-Mortar” Nanostructured Interphase for Glass Fiber-Reinforced Polymer Composites

The fiber–matrix interface plays a critical role in determining composite mechanical properties. While a strong interface tends to provide high strength, a weak interface enables extensive debonding, leading to a high degree of energy absorption. Balancing these conflicting requirements by engineering composite interfaces to improve strength and toughness simultaneously still remains a great challenge. Here, a nanostructured fiber coating was realized to manifest the critical characteristics of natural nacre, at a reduced length scale, consistent with the surface curvature of fibers. The new interphase contains a high proportion (∼90 wt %) of well-aligned inorganic platelets embedded in a polymer; the window of suitable platelet dimensions is very narrow, with an optimized platelet width and thickness of about 130 and 13 nm, respectively. An anisotropic, nanostructured coating was uniformly and conformally deposited onto a large number of 9 μm diameter glass fibers, simultaneously, using self-limiting layer-by-layer assembly (LbL); this parallel approach demonstrates a promising strategy to exploit LbL methods at scale. The resulting nanocomposite interphase, primarily loaded in shear, provides new mechanisms for stress dissipation and plastic deformation. The energy released by fiber breakage in tension appear to spread and dissipate within the nanostructured interphase, accompanied by stable fiber slippage, while the interfacial strength was improved up to 30%

Impatto del lockdown sulla spesa degli italiani: quale futuro per l’e-grocery?

I decisori politici e gli operatori del settore si stanno impegnando in nuovi progetti volti a minimizzare l’impatto ambientale del trasporto merci dell’ultimo miglio. A questo scopo potrebbe risultare funzionale l’evoluzione verso la modalità di spesa online (e-grocery) laddove, grazie a un servizio pianificato di consegna delle merci, riuscisse a ridurre il numero di viaggi e/o di veicoli circolanti e, di conseguenza, le esternalità negative legate al settore del trasporto merci urbano. Il “lockdown di primavera”, imposto tra marzo e maggio del 2020 per contrastare il diffondersi della pandemia da SARS-Covid19, ha avuto un impatto importante su qualità e quantità degli spostamenti, che sono calati drasticamente per via delle restrizioni governative agli spostamenti vigenti sui vari territori nazionali. In questo lavoro si intende dunque esplorare se e in che misura le famiglie italiane abbiano modificato, durante il periodo di lockdown, le proprie abitudini nell’effettuare la spesa, eventualmente preferendo la modalità online. Inoltre si cerca di capire anche se tale modifica del comportamento potrebbe prolungarsi al termine del periodo di restrizioni. A questo scopo TRElab ha somministrato online un questionario su scala nazionale a più di 600 rispondenti. I risultati dello studio mostrano non solo che il lockdown ha contribuito, spesso per mancanza di alternative, a spingere le famiglie italiane verso nuove modalità di acquisto e ricezione della spesa, con un conseguente incremento del flusso di richieste per il comparto dell’e-grocery, ma evidenziano una propensione all’utilizzo del canale di vendita virtuale per la spesa anche in un prossimo futur