This report presents a first-principles investigation of the structural, electronic, and optical properties of perovskite oxynitrides BaTaO2 N by means of density functional theory（DFT） calculations using the full-p...This report presents a first-principles investigation of the structural, electronic, and optical properties of perovskite oxynitrides BaTaO2 N by means of density functional theory（DFT） calculations using the full-potential linearized augmented plane wave（FP-LAPW） method. Three possible structures（P4mm, I4/mmm, and Pmma） are considered according to the TaO4N2 octahedral configurations. The calculated structural parameters are found to be in good agreement with the previous theoretical and experimental results. Moreover, the electronic band structure dispersion, total, and partial densities of electron states are investigated to explain the origin of bandgaps and the contribution of each orbital＇s species in the valence and the conduction bands. The calculated minimum bandgaps of the P4 mm, I4/mmm, and Pmma structures are 1.83 e V, 1.59 e V, and 1.49 e V, respectively. Furthermore, the optical properties represented by the dielectric functions calculated for BaTaO2 N show that the I4/mmm phase absorbs the light at a large window in both the visible and UV regions,whereas the other two structures（P4mm and Pmma） are more active in the UV region. Our investigations provide important information for the potential application of this material.展开更多
Background: The prevalence of overweight and obesity associated with oxidative stress and immune abnormalities is continuously increasing. Antioxidant supplementations might counteract potential damage caused by ROS t...Background: The prevalence of overweight and obesity associated with oxidative stress and immune abnormalities is continuously increasing. Antioxidant supplementations might counteract potential damage caused by ROS to cellular tissues. Objective: To determine the role of vitamins on immune improvement during obesity, we investigated in vitro effects of vitamins C, E, and NADH on mitogen-stimulated proliferation, Th1- and Th2-type cytokine production, and oxidant/antioxidant status of lymphocytes isolated from obese patients. Methods: Peripheral blood lymphocytes were isolated using a density gradient of Histopaque. They were in vitro cultured and stimulated by Con A in the presence or absence of vitamins. Cell proliferation was determined by MTT assay and interleukin-2, interleukin-4 and interferon-γ (INFγ) secretions. Cell oxidant/antioxidant balance was studied by assaying glutathione (GSH), malondialdehyde (MDA), carbonyl protein levels, catalase activity and micronucli frequency. Results: Obesity is associated with enhanced oxidative stress response. Indeed, vitamin C, E and NADH improved significantly lymphocyte proliferation and diminished cellular oxidative stress. Conclusion: Treatments of lymphocytes with vitamins had beneficial effects on lymphocyte proliferation, cytokines secretions and redox status, generating an anti-inflammatory profile and should be considered in therapeutic approaches for normalizing immune cell function in obesity.展开更多
文摘This report presents a first-principles investigation of the structural, electronic, and optical properties of perovskite oxynitrides BaTaO2 N by means of density functional theory（DFT） calculations using the full-potential linearized augmented plane wave（FP-LAPW） method. Three possible structures（P4mm, I4/mmm, and Pmma） are considered according to the TaO4N2 octahedral configurations. The calculated structural parameters are found to be in good agreement with the previous theoretical and experimental results. Moreover, the electronic band structure dispersion, total, and partial densities of electron states are investigated to explain the origin of bandgaps and the contribution of each orbital＇s species in the valence and the conduction bands. The calculated minimum bandgaps of the P4 mm, I4/mmm, and Pmma structures are 1.83 e V, 1.59 e V, and 1.49 e V, respectively. Furthermore, the optical properties represented by the dielectric functions calculated for BaTaO2 N show that the I4/mmm phase absorbs the light at a large window in both the visible and UV regions,whereas the other two structures（P4mm and Pmma） are more active in the UV region. Our investigations provide important information for the potential application of this material.
文摘Background: The prevalence of overweight and obesity associated with oxidative stress and immune abnormalities is continuously increasing. Antioxidant supplementations might counteract potential damage caused by ROS to cellular tissues. Objective: To determine the role of vitamins on immune improvement during obesity, we investigated in vitro effects of vitamins C, E, and NADH on mitogen-stimulated proliferation, Th1- and Th2-type cytokine production, and oxidant/antioxidant status of lymphocytes isolated from obese patients. Methods: Peripheral blood lymphocytes were isolated using a density gradient of Histopaque. They were in vitro cultured and stimulated by Con A in the presence or absence of vitamins. Cell proliferation was determined by MTT assay and interleukin-2, interleukin-4 and interferon-γ (INFγ) secretions. Cell oxidant/antioxidant balance was studied by assaying glutathione (GSH), malondialdehyde (MDA), carbonyl protein levels, catalase activity and micronucli frequency. Results: Obesity is associated with enhanced oxidative stress response. Indeed, vitamin C, E and NADH improved significantly lymphocyte proliferation and diminished cellular oxidative stress. Conclusion: Treatments of lymphocytes with vitamins had beneficial effects on lymphocyte proliferation, cytokines secretions and redox status, generating an anti-inflammatory profile and should be considered in therapeutic approaches for normalizing immune cell function in obesity.
