281 research outputs found

    Phase diagram of the mixed spin-2 and spin-5/2 Ising system with two different single-ion anisotropies

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    AbstractWe study the effect of two different single-ion anisotropies in the phase diagram and in the compensation temperature of mixed spin-2 and spin-5/2 Ising ferrimagnetic system. We employed the mean-field theory based on the Bogoliubov inequality for Gibbs free energy. We use the Landau expansion of free energy in the order parameter to describe the phase diagram. In the temperature versus single-ion anisotropy plane the phase diagram displays tricritical behavior. The critical and compensation temperatures increase with increasing values of the single-ion anisotropies

    Discovery and Characterization of Peptide Inhibitors for Calcium and Integrin Binding Protein 1

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    Calcium and integrin binding protein 1 (CIB1) is an EF-hand-containing, small intracellular protein that has recently been implicated in cancer cell survival and proliferation. In particular, CIB1 depletion significantly impairs tumor growth in triple-negative breast cancer (TNBC). Thus, CIB1 is a potentially attractive target for cancer chemotherapy that has yet to be validated by a chemical probe. To produce a probe molecule to the CIB1 helix 10 (H10) pocket and demonstrate that it is a viable target for molecular intervention, we employed random peptide phage display to screen and select CIB1-binding peptides. The top peptide sequence selected, UNC10245092, was produced synthetically, and binding to CIB1 was confirmed by isothermal titration calorimetry (ITC) and a time-resolved fluorescence resonance energy transfer (TR-FRET) assay. Both assays showed that the peptide bound to CIB1 with low nanomolar affinity. CIB1 was cocrystallized with UNC10245092, and the 2.1 Å resolution structure revealed that the peptide binds as an α-helix in the H10 pocket, displacing the CIB1 C-terminal H10 helix and causing conformational changes in H7 and H8. UNC10245092 was further derivatized with a C-terminal Tat-derived cell penetrating peptide (CPP) to demonstrate its effects on TNBC cells in culture, which are consistent with results of CIB1 depletion. These studies provide a first-in-class chemical tool for CIB1 inhibition in cell culture and validate the CIB1 H10 pocket for future probe and drug discovery efforts

    Symptom variability over the course of the day in patients with stable COPD in Brazil: a real-world observational study

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    Objetivo: Analisar os sintomas em diferentes momentos do dia em pacientes com DPOC. Métodos: Estudo observacional multicêntrico de corte transversal em oito centros brasileiros. Foram avaliados os sintomas matinais, diurnos e noturnos em pacientes com DPOC estável. Resultados: Foram incluídos 593 pacientes em tratamento regular, sendo 309 (52,1%) do sexo masculino e 92 (15,5%) fumantes ativos. A média de idade foi de 67,7 anos, e a média de VEF1 foi de 49,4% do valor previsto. Os pacientes com sintomas mais graves (n = 183; 30,8%), em comparação com aqueles com sintomas leves e moderados, apresentaram pior nível de atividade física (p = 0,002), maior limitação ao fluxo aéreo (p < 0,001), exacerbações ambulatoriais (p = 0,002) e hospitalares (p = 0,043) mais frequentemente e piores resultados em instrumentos específicos. Os sintomas matinais e noturnos mais frequentes foram dispneia (em 45,2% e 33,1%, respectivamente), tosse (em 37,5% e 33,3%, respectivamente) e chiado (em 24,4% e 27,0%, respectivamente). Houve forte correlação da intensidade dos sintomas diurnos com sintomas matinais (r = 0,65, p < 0,001), sintomas noturnos (r = 0,60, p < 0,001), bem como com o escore do COPD Assessment Test (r = 0,62; p < 0,001); porém, houve uma correlação fraca com VEF1 (r = −0,205; p < 0,001). Conclusões: A dispneia foi mais frequente no período matinal do que no período noturno. Ter sintomas matinais e/ou noturnos foi associado à pior gravidade dos sintomas diurnos. A intensidade dos sintomas foi fortemente associada a pior qualidade de vida e frequência de exacerbações, mas fracamente associada à limitação ao fluxo aéreo.463Objective: To analyze symptoms at different times of day in patients with COPD. Methods: This was a multicenter, cross-sectional observational study conducted at eight centers in Brazil. We evaluated morning, daytime, and nighttime symptoms in patients with stable COPD. Results: We included 593 patients under regular treatment, of whom 309 (52.1%) were male and 92 (15.5%) were active smokers. The mean age was 67.7 years, and the mean FEV1 was 49.4% of the predicted value. In comparison with the patients who had mild or moderate symptoms, the 183 (30.8%) with severe symptoms were less physically active (p = 0.002), had greater airflow limitation (p < 0.001), had more outpatient exacerbations (p = 0.002) and more inpatient exacerbations (p = 0.043), as well as scoring worse on specific instruments. The most common morning and nighttime symptoms were dyspnea (in 45.2% and 33.1%, respectively), cough (in 37.5% and 33.3%, respectively), and wheezing (in 24.4% and 27.0%, respectively). The intensity of daytime symptoms correlated strongly with that of morning symptoms (r = 0.65, p < 0.001) and that of nighttime symptoms (r = 0.60, p < 0.001), as well as with the COPD Assessment Test score (r = 0.62; p < 0.001), although it showed only a weak correlation with FEV1 (r = −0.205; p < 0.001). Conclusions: Dyspnea was more common in the morning than at night. Having morning or nighttime symptoms was associated with greater daytime symptom severity. Symptom intensity was strongly associated with poor quality of life and with the frequency of exacerbations, although it was weakly associated with airflow limitation

    Quantum walks: a comprehensive review

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    Quantum walks, the quantum mechanical counterpart of classical random walks, is an advanced tool for building quantum algorithms that has been recently shown to constitute a universal model of quantum computation. Quantum walks is now a solid field of research of quantum computation full of exciting open problems for physicists, computer scientists, mathematicians and engineers. In this paper we review theoretical advances on the foundations of both discrete- and continuous-time quantum walks, together with the role that randomness plays in quantum walks, the connections between the mathematical models of coined discrete quantum walks and continuous quantum walks, the quantumness of quantum walks, a summary of papers published on discrete quantum walks and entanglement as well as a succinct review of experimental proposals and realizations of discrete-time quantum walks. Furthermore, we have reviewed several algorithms based on both discrete- and continuous-time quantum walks as well as a most important result: the computational universality of both continuous- and discrete- time quantum walks.Comment: Paper accepted for publication in Quantum Information Processing Journa
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