381 research outputs found

    Dynamical influence of vortex-antivortex pairs in magnetic vortex oscillators

    Full text link
    We study the magnetization dynamics in a nanocontact magnetic vortex oscillators as function of temperature. Low temperature experiments reveal that the dynamics at low and high currents differ qualitatively. At low currents, we excite a temperature independent standard oscillation mode, consisting in the gyrotropic motion of a free layer vortex about the nanocontact. Above a critical current, a sudden jump of the frequency is observed, concomitant with a substantial increase of the frequency versus current slope factor. Using micromagnetic simulation and analytical modeling, we associate this new regime to the creation of a vortex-antivortex pair in the pinned layer of the spin valve. The vortex-antivortex distance depends on the Oersted field which favors a separation, and on the exchange bias field, which favors pair merging. The pair in the pinned layer provides an additional spin torque altering the dynamics of the free layer vortex, which can be quantitatively accounted for by an analytical model

    High levels of shading as a sustainable application for mitigating drought, in modern apple production

    Get PDF
    The sustainability of reducing light in apple orchards under well-watered (ww) and water stress (ws) conditions was evaluated for water relations, plant gas exchanges, fruit growth, yield determinants, and fruit quality over three years. A black (B) 28% shading net was compared with two different 50% shading nets: red (R) and white (W). Each net was combined with two irrigation regimes (ww and ws) based on plant water status. Under ww and ws conditions, increasing shade from 28% to 50% was not detrimental for plant gas exchanges, yield, or quality over three years. Higher shade improved plant water status regardless of irrigation regime. Higher shading could be considered sustainable in apple orchards over several seasons. Fruit quality was more sensitive to plant water status than to light reduction. ws increased fruit soluble solid content and relative dry matter, regardless of shading, and this was positively reflected in consumer’s preference. When water availability is limited, increasing shading to 50% can help save water and maintain high-quality yields associated with water stress. Given the likely reductions of water availability in agriculture, growers and consultants may consider shading apple orchards as a sustainable and safe horticultural technique to save water

    Current evidence to propose different food supplements for weight loss: a comprehensive review

    Get PDF
    The use of food supplements for weight loss purposes has rapidly gained popularity as the prevalence of obesity increases. Navigating through the vast, often low quality, literature available is challenging, as is providing informed advice to those asking for it. Herein, we provide a comprehensive literature revision focusing on most currently marketed dietary supplements claimed to favor weight loss, classifying them by their purported mechanism of action. We conclude by proposing a combination of supplements most supported by current evidence, that leverages all mechanisms of action possibly leading to a synergistic effect and greater weight loss in the foreseen absence of adverse events. Further studies will be needed to confirm the weight loss and metabolic improvement that may be obtained through the use of the proposed combination

    Discovery and Preliminary Characterization of Translational Modulators that Impair the Binding of eIF6 to 60S Ribosomal Subunits

    Get PDF
    Eukaryotic initiation factor 6 (eIF6) is necessary for the nucleolar biogenesis of 60S ribosomes. However, most of eIF6 resides in the cytoplasm, where it acts as an initiation factor. eIF6 is necessary for maximal protein synthesis downstream of growth factor stimulation. eIF6 is an antiassociation factor that binds 60S subunits, in turn preventing premature 40S joining and thus the formation of inactive 80S subunits. It is widely thought that eIF6 antiassociation activity is critical for its function. Here, we exploited and improved our assay for eIF6 binding to ribosomes (iRIA) in order to screen for modulators of eIF6 binding to the 60S. Three compounds, eIFsixty-1 (clofazimine), eIFsixty-4, and eIFsixty-6 were identified and characterized. All three inhibit the binding of eIF6 to the 60S in the micromolar range. eIFsixty-4 robustly inhibits cell growth, whereas eIFsixty-1 and eIFsixty-6 might have dose- and cell-specific effects. Puromycin labeling shows that eIF6ixty-4 is a strong global translational inhibitor, whereas the other two are mild modulators. Polysome profiling and RT-qPCR show that all three inhibitors reduce the specific translation of well-known eIF6 targets. In contrast, none of them affect the nucleolar localization of eIF6. These data provide proof of principle that the generation of eIF6 translational modulators is feasible

    Valutazione della bontà educativa dei casi clinici di ECCE, il programma di formazione a distanza (FAD) basato sulle evidenze destinato ai medici italiani

    Get PDF
    OBIETTIVO. Valutare la qualit\ue0 dei percorsi clinici di un programma FAD destinato a tutti i medici italiani verificando le loro propriet\ue0 psicometriche. METODI. AIFA ha lanciato un programma nazionale di sostegno dell\u2019informazione indipendente tramite la distribuzione gratuita ai medici di Clinical Evidence (CE). Sulla base dei contenuti di CE \ue8 stato sviluppato un programma FAD all\u2019interno del sistema di Educazione Continua in Medicina (ECM) dal nome ECCE, anch\u2019esso gratuito. I medici hanno accesso a CE online e ai relativi percorsi clinici. Superandoli il medico ottiene i crediti ECM. Nel corso del 2006 \ue8 stata valutata la qualit\ue0 di un campione di venti percorsi, su un totale di 120. La valutazione formale della qualit\ue0 dei 20 casi selezionati \ue8 avvenuta attraverso le seguenti dimensioni psicometriche: Giudizio generale sui percorsi da parte degli utilizzatori (face validity); Valutazione dei contenuti da parte di clinici esperti (content validity); Valutazione della attendibilit\ue0 del test attraverso un criterio di consistenza interna (internal reliability); Difficolt\ue0 degli items; Capacit\ue0 del test di rilevare una modificazione della conoscenza (responsiveness). RISULTATI: Alcune migliaia di utenti hanno partecipato alla valutazione fornendo esiti contrastanti: mentre la face e content validity sono state valutate positivamente dagli utilizzatori e dai clinici esperti, altri parametri come l\u2019internal reliability e la difficolt\ue0 degli items hanno mostrato grande variabilit\ue0 tra i percorsi. Sette casi mostrano un valore di alpha complessivo inferiore a 0.50 (soglia minima di affidabilit\ue0). I casi si sono dimostrati nel complesso medio-facili. Facendo riferimento solo alle proprie conoscenze i partecipanti rispondevano correttamente a circa a met\ue0 delle domande. La lettura delle fonti era associata a un miglioramento della performance (miglioramento prima-dopo statisticamente significativo, p<0.05 per 19/20 percorsi). CONCLUSIONI: L\u2019importante eterogeneit\ue0 tra percorsi dimostrerebbe come differenti casi possono analizzare in maniera molto disomogenea il domino conoscenza evidence-based derivata dai contenuti di CE

    Straight aortic endograft in abdominal aortic disease

    Get PDF
    Background: We describe our 8-year experience with the use of endovascular techniques (ET) for the treatment of abdominal aortic aneurysms (AAA) through a straight endograft. Methods: We retrospectively reviewed data of all patients who were treated for AAA using ET in two centres from 1998 to 2012 and who received a single straight endograft (group A) or a double straight tube (group B). Outcomes were analyzed to assess survival, absence of endoleak and absence of reintervention for both groups. Log-rank and Chi-Square were used as appropriate to make comparison between the two groups. P values <.05 were considered statistically significant. Results: Fifty-three patients from 1998 to May 2012 were treated for AAA using a straight endograft. In 28 cases (52.8%) a single aortic straight tube was used (Group A), while in the remaining cases a "double trombone technique" was used (Group B). Primary success was obtained in 52 cases (98.1%). In one patient of group A immediately after the operation we observed a type Ia endoleak, which was correct with a proximal aortic cuff. Fluoroscopy time, operation time, amount of intraprocedural contrast medium and blood loss were slightly higher for group B, even if not significantly. Mortality at 30 days was nil for both groups. Mean follow-up was 49 months (range 2-153 months). Five patients died in group A, four of them for a neoplastic disease and the remaining for aortic rupture. No patients died in group B. Endoleaks occurred more frequently in patients of group A (5 type I endoleaks and 1 type II endoleak from a lumbar artery). Reintervention were more frequent for patients of group A, being type I endoleak the main cause. A stent fracture was observed in a patient who received EVAR by "trombone technique" 3 months later. Reintervention was then necessary and a third stent was successfully placed to cover the lesion. Conclusions: In our experience the endovascular repair of AAA using straight aortic endografts was a safe and effective technique. Reintervention and endoleaks were slightly more frequent in patients who had received a single endograft compared to patients who were treated using the "trombone technique"

    Quality of life and treatment satisfaction in adults with Type 1 diabetes: A comparison between continuous subcutaneous insulin infusion and multiple daily injections

    Get PDF
    Aims: The aim of this case-control study was to compare quality of life (QoL) and treatment satisfaction in adults with Type 1 diabetes (T1DM) treated with either continuous subcutaneous insulin infusion (CSII) or multiple daily injections (MDI). Methods: Consecutive patients aged between 18 and 55 years, and attending diabetes clinics for a routine visit, completed the Diabetes-Specific Quality-of-Life Scale (DSQOLS), the Diabetes Treatment Satisfaction Questionnaire (DTSQ) and the SF-36 Health Survey (SF-36). Case (CSII) and control subjects (MDI) were recruited in a 1 : 2 ratio. Results: Overall, 1341 individuals were enrolled by 62 diabetes clinics; 481 were cases and 860 control subjects. Cases had a longer diabetes duration and were more likely to have eye and renal complications. Age, school education, occupation and HbA1c were similar. Of control subjects, 90% followed glargine-based MDI regimens and 10% used NPH-based MDI regimens. On multivariate analysis, after adjusting for socioeconomic and clinical characteristics, scores in the following areas of the DSQOLS were higher in cases than control subjects: diet restrictions (β = 5.96; P &lt; 0.0001), daily hassles (β = 3.57; P = 0.01) and fears about hypoglycaemia (β = 3.88; P = 0.006). Treatment with CSII was also associated with a markedly higher DTSQ score (β = 4.13; P &lt; 0.0001) compared with MDI. Results were similar when CSII was compared separately with glargine- or NPH-based MDI regimens. Conclusions: This large, non-randomized, case-control study suggests quality of life gains deriving from greater lifestyle flexibility, less fear of hypoglycaemia, and higher treatment satisfaction, when CSII is compared with either glargine-based or NPH-based MDI regimens. © 2008 The Authors
    • …
    corecore