652 research outputs found

    Orbital Selective Magnetism in the Spin-Ladder Iron Selenides Ba1−x_{1-x}Kx_{x}Fe2_2Se3_3

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    Here we show that the 2.80(8) {\mu}B/Fe block antiferromagnetic order of BaFe2Se3 transforms into stripe antiferromagnetic order in KFe2Se3 with a decrease in moment to 2.1(1) {\mu}B/Fe. This reduction is larger than expected from the change in electron count from Ba2+^{2+} to K+^{+}, and occurs with the loss of the displacements of Fe atoms from ideal positions in the ladders, as found by neutron pair distribution function analysis. Intermediate compositions remain insulating, and magnetic susceptibility measurements show a suppression of magnetic order and probable formation of a spin-glass. Together, these results imply an orbital-dependent selection of magnetic versus bonded behavior, driven by relative bandwidths and fillings.Comment: Final versio

    Influence of Installation Conditions on Heating Bodies Thermal Output: Preliminary Experimental Results☆

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    Abstract Heating bodies are thermodynamic systems whose heat output is strongly dependent on boundary conditions and in about a century several attempts have been made for its experimental determination. To this aim, at the beginning of 60s, in Europe different national standards were adopted (e.g. in 1967 in Italy the UNI 6514/1967). At European level, the EN 442-1:2014 and EN 442-2:2014 allows the heating body heat output estimation with an expanded uncertainty lower than 1% and they are now accepted in various international markets. The EN 442 also allows heat output calculation in operating conditions different from standard ones by employing theoretical-experimental correlations that, by their nature, are not able to include any possible actual operating condition. In fact, in actual operating conditions the heating body heat output depends on several factors, among which: i) installation position with respect to the wall and the floor; ii) presence grid/shelf/niche or an obstruction caused by curtains on the heating body; iii) thermo-fluid-dynamic condition variations (inlet flow rate and temperature); iv) hydraulic connections. Radiators represent the most spread heating body (installed since the end of '800) and in the last decades different radiators typologies have been proposed on the market, characterized by different materials, sizes, shapes, etc. In the present paper the authors present the preliminary result of an experimental campaign on field for the heat output measurement of different radiators typologies (cast iron, aluminum) as a function of different installation and operating conditions. The influence on the heating body performance and the associate technical-economical consequences in terms of heat cost allocation accuracy have been investigated

    Non-uniform carrier density in Cd3_3As2_2 evidenced by optical spectroscopy

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    We report the detailed optical properties of Cd3_3As2_2 crystals in a wide parameter space: temperature, magnetic field, carrier concentration and crystal orientation. We investigate high-quality crystals synthesized by three different techniques. In all the studied samples, independently of how they were prepared and how they were treated before the optical experiments, our data indicate conspicuous fluctuations in the carrier density (up to 30%). These charge puddles have a characteristic scale of 100 ÎŒ\mum, they become more pronounced at low temperatures, and possibly, they become enhanced by the presence of crystal twinning. The Drude response is characterized by very small scattering rates (∌1\sim 1 meV) for as-grown samples. Mechanical treatment, such as cutting or polishing, influences the optical properties of single crystals, by increasing the Drude scattering rate and also modifying the high frequency optical response. Magneto-reflectivity and Kerr rotation are consistent with electron-like charge carriers and a spatially non-uniform carrier density.Comment: Accepted in Physical Review

    Right ventricular dysfunction parallels left ventricular functional involvement in women with breast cancer experiencing subclinical cardiotoxicity

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    Abstract Funding Acknowledgements Type of funding sources: None. Background Cancer therapy related cardiac toxicity disease (CRCTD) of the left ventricle (LV)can influence the outcome of oncologic patients. Little is known on CRCTD related right ventricular (RV)dysfunction even though RV involvement has been proven to be a remarkable prognosticator in heart failure. Purpose To analyse parallel changes in LV and RV function occurring during the course of cancer therapy in women affected by breast cancer by using both standard and speckle tracking echocardiography. Methods Fifty Her-2 positive breast cancer women (age = 53.6 ± 11.7 years) underwent sequential cancer therapy protocol including anthracycline (ANT) epirubicine + cyclophosphamide (4 cycles) followed by a total amount of 18 cycles with trastuzumab (TRZ) + paclitaxel. A complete echo-Doppler exam, including LV and RV global longitudinal strain (GLS)as well as RV septal and free wall longitudinal strain (SLS and FWLS respectively) assessment, was performed at baseline, after ANT end and after TRZ completion. Patients with overt heart failure and LV ejection fraction < 50%, coronary artery disease,atrial fibrillation, hemodinamically significant valve disease and inadequate echo were excluded. Overt CRCTD was defined according guidelines and both subclinical LV and RV CRCTD as a LV and RV GLS drop from baseline >15%. Results None of the patients experienced overt CTCRD but 6 patients (14%) showed subclinical LV dysfunction and 33 (66%) had a significant drop of RV longitudinal function.The comparison of standard echo-Doppler exam at baseline and after ANT and TRZ completion did not show significant changes of LV and RV systolic and diastolic parameters. Conversely, a progressive significant reduction of RV GLS (p < 0.002 after TRZ), SLS and FWLS and, with a lower extent, of LV GLS (p < 0.02 after TRZ) was observed after ANT and TRZ completion (Figure). Percentage reduction in RV GLS (DRV GLS) from baseline to ANT end correlated with LV GLS both at EC end (r=-0.40, p = 0.006) and after TRZ completion (r=-0.62, p < 0.0001). Conclusions Detrimental cardiac effects of cancer therapy involve both LV and RV systolic longitudinal function. Progressive RV dysfunction is evident through ANT and TRZ treatment. Early RV dysfunction parallels LV involvement and predicts subsequent LV subclinical dysfunction. A comprehensive LV and RV longitudinal function assessment might better predict the onset of CRCTD in breast cancer patients. Abstract Figure

    Le Difficoltà di Calcolo e l’Ansia Matematica. Uno studio sulla Scuola Secondaria di Primo Grado.

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    Diversi studi evidenziano come tanti studenti sperimen- tano ansia e senso di inadeguatezza in compiti che coin- volgono le abilitĂ  di calcolo (Ashcraft, 2002; Maloney e Beilock, 2012) e supportano l’idea che l’alunno sia influenzato nell’apprendimento della matematica da tali sentimenti e come questi siano associati ad un minore rendimento in questa disciplina (Lee, 2009). Gli studi sulle “convinzioni” permettono di affermare che l’apprendimento di uno studente Ăš orientato dal proprio SĂš. Tali idee del tutto soggettive e non lega- te alle conoscenze oggettive connesse alla disciplina, svolgono un ruolo di filtro rispetto all’apprendimento e interpretazione delle nuove informazioni (Boscolo, 1997). Questo sistema di idee influenza l’apprendimento dell’alunno, fornendogli, a seconda dei casi, un valido supporto per sostenere gli sforzi nel processo di ap- prendimento, oppure un condizionamento negativo che rende vano ogni tentativo di riuscita (Demarchi, 2015). L’intento del presente studio Ăš stato quello di indaga- re la competenza oggettiva nell’area del calcolo e la competenza soggettiva intesa come l’ansia percepita ri- spetto all’apprendimento matematico e alla valutazione matematica ed infine l’ansia scolastica generalizzata. Lo studio Ăš stato condotto su un gruppo di 54 alunni frequentanti la scuola secondaria di primo grado di un Istituto Comprensivo della provincia di Taranto. La ricerca ha evidenziato come le prestazioni in ma- tematica peggiorino all’aumentare della classe di fre- quenza e come, buone prestazioni nell’area del calcolo corrispondono a piĂč bassi livelli di ansia nelle tre di- mensioni: Ansia da Apprendimento Matematico, Ansia da Valutazione Matematica e Ansia Scolastica Genera- lizzata

    The evolving therapeutic landscape of trastuzumab-drug conjugates: Future perspectives beyond HER2-positive breast cancer

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    A novel class of drugs, antibody-drug conjugates (ADCs), are now rapidly emerging as highly effective treatments for solid tumours. ADCs conjugate conventional chemotherapeutics with highly selective targeted monoclonal antibodies. Anti-HER2 therapies selectively target cancer cells expressing human epidermal growth factor receptor 2 (HER2), among them trastuzumab has been the first HER2-targeting monoclonal antibody to achieve successful results that made it the backbone of anti-HER2 therapies. Trastuzumab drug conjugates (T-DCs), use trastuzumab as a selective antibody to lead cytotoxic drugs inside cancer cells. Trastuzumab-emtansine (T-DM1) and trastuzumab-deruxtecan (T-Dxd) are the two approved T-DCs. T-Dxd along with other five T-DCs represents “second generation ADCs” that has been firstly tested in HER2 positive breast cancer (BC) and then in HER2-low BC and other cancers showing promising results thanks to extraordinary and innovative pharmacokinetic and pharmacodynamic characteristics. The evidence generated so far are establishing them as a completely new class of agents effective in solid cancer treatments but also warrants physicians against unconventional toxicity profiles. The role of T-DCs in HER2-positive BC has been largely reviewed, while in this review, we provided for the first time in literature an overview of trastuzumab drug conjugates (T-DCs) approved and/or in clinical development with a specific focus on their efficacy and safety profile in HER2-low BC and other solid tumours different from BC. We started by analysing T-DCs biological characteristics that underly the differences in T-DCs pharmacodynamics and safety profile, then presented the main evidence on the activity and efficacy of these emerging T-DCs in HER2-low BC and other HER2 overexpressing and/or mutated solid tumours and lastly, we provided an overview of the complex and still evolving scenario in which these compounds should be allocated. A specific focus on possible combination strategies with other drugs such as immunotherapy, chemotherapy and target therapy, to increase T-DCs activity and eventually overcome future upcoming resistance mechanisms, are here also critically reviewed

    Health-related quality of life in breast cancer patients treated with CDK4/6 inhibitors: a systematic review

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    Background: Evaluation of health-related quality of life (HR-QoL) among cancer patients has gained an increasing importance and is now a key determinant of anticancer treatments’ value. HR-QoL has been assessed in trials testing cyclin-dependent kinase 4/6 inhibitors (CDK4/6i) in breast cancer (BC), using various questionnaires at different timepoints. HR-QoL reports from BC patients treated with CDK4/6i in the real-world setting are also available. Methods: We systematically reviewed the literature, searching for full-length articles, and selected conference abstracts reporting data on HR-QoL in BC patients at any stage and of any molecular subtype treated with abemaciclib, palbociclib or ribociclib. Results: A total of 533 full-length articles and 143 abstracts were retrieved. After screening for eligibility, 38 records were included (31 clinical trials; 7 real-world reports). Assessment methods were heterogeneous across studies in terms of questionnaires, evaluation timepoints and endpoints. Overall, adding CDK4/6i to endocrine therapy did not worsen patients’ HR-QoL, with a positive trend towards pain improvement. Gastrointestinal scores (diarrhea, nausea and appetite loss) statistically favored the control arm among metastatic BC patients receiving abemaciclib, whereas they were superimposable in the early setting. The combination of palbociclib and endocrine therapy showed similar HR-QoL outcomes compared with endocrine therapy alone, but determined better scores compared with chemotherapy. HR-QoL was specifically assessed in premenopausal patients treated with ribociclib, showing similar scores compared with postmenopausal patients. Conclusions: Despite methodological heterogeneity does not allow a proper comparison, HR-QoL was generally maintained with CDK4/6i. However, differences between abemaciclib, palbociclib and ribociclib exist and mainly rely on the distinct safety profiles of the compounds. These differences should be acknowledged and taken into account in the clinical practice
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