Hydration Mechanisms and Proton Conduction in the Mixed Ionic–Electronic Conductors Ba₄Nb₂O₉ and Ba₄Ta₂O₉

We studied the behavior of hydrogen in the mixed ionic–electronic conductors γ-Ba₄Nb₂O₉ and 6H-Ba₄Ta₂O₉ using a combination of experimental (neutron diffraction and inelastic neutron scattering) and computational (ab initio molecular dynamics) methods. Although these compounds have isostructural low-temperature polymorphs, they adopt distinct forms in the high-temperature conducting regime. We show here that they also have distinct mechanisms for hydration and ionic conduction. Hydration of γ-Ba₄Nb₂O₉ is localized to 2-D layers in the structure that contain a 1:1 ratio of isolated but adjacent NbO₄ and NbO₅ polyhedra. OH^– and H⁺ ions combine with two polyhedra, respectively, to form complete layers of NbO₄OH polyhedra, giving rise to a stoichiometric hydrated form γ-III-Ba₄Nb₂O₉·¹/₃H₂O. Protons then diffuse through these 2-D layers by “hopping” between oxygen atoms on adjacent polyhedra. In the case of 6H-Ba₄Ta₂O₉, hydration occurs by intercalating intact water molecules into the structure up to a maximum of ∼0.375 H₂O per formula unit. This explains the unusual local and long-range structural distortions in the hydrated form observed by neutron diffraction. Diffusion then occurs by water molecules moving between neighboring symmetry equivalent positions. These fundamentally different hydration and proton conduction mechanisms explain why 6H-Ba₄Ta₂O₉ has the less well-defined and higher maximum water content, while γ-Ba₄Nb₂O₉ has the higher proton conductivity

Hydration Mechanisms and Proton Conduction in the Mixed Ionic–Electronic Conductors Ba₄Nb₂O₉ and Ba₄Ta₂O₉

We studied the behavior of hydrogen in the mixed ionic–electronic conductors γ-Ba₄Nb₂O₉ and 6H-Ba₄Ta₂O₉ using a combination of experimental (neutron diffraction and inelastic neutron scattering) and computational (ab initio molecular dynamics) methods. Although these compounds have isostructural low-temperature polymorphs, they adopt distinct forms in the high-temperature conducting regime. We show here that they also have distinct mechanisms for hydration and ionic conduction. Hydration of γ-Ba₄Nb₂O₉ is localized to 2-D layers in the structure that contain a 1:1 ratio of isolated but adjacent NbO₄ and NbO₅ polyhedra. OH^– and H⁺ ions combine with two polyhedra, respectively, to form complete layers of NbO₄OH polyhedra, giving rise to a stoichiometric hydrated form γ-III-Ba₄Nb₂O₉·¹/₃H₂O. Protons then diffuse through these 2-D layers by “hopping” between oxygen atoms on adjacent polyhedra. In the case of 6H-Ba₄Ta₂O₉, hydration occurs by intercalating intact water molecules into the structure up to a maximum of ∼0.375 H₂O per formula unit. This explains the unusual local and long-range structural distortions in the hydrated form observed by neutron diffraction. Diffusion then occurs by water molecules moving between neighboring symmetry equivalent positions. These fundamentally different hydration and proton conduction mechanisms explain why 6H-Ba₄Ta₂O₉ has the less well-defined and higher maximum water content, while γ-Ba₄Nb₂O₉ has the higher proton conductivity

New High-Pressure Polymorph of the Nonlinear Optical Crystal BaTeMo₂O₉

High-pressure synchrotron X-ray diffraction on the nonlinear optical crystal α-BaTeMo₂O₉ (α -BTM) has revealed a new polymorph of γ-BTM having a monoclinic space group of <i>P</i>2₁. This first order phase transition from the orthorhombic <i>Pca</i>2₁ to the new monoclinic <i>P</i>2₁ structure occurs at 3.8 GPa pressure. The mechanism of the phase transition under high pressure is attributed to the anisotropic pressure response along different crystallographic directions

DataSheet_1_Nimotuzumab combined with chemoradiotherapy for the treatment of cervical cancer: A meta-analysis of randomized controlled trials.docx

ObjectivesTo assess the clinical efficacy and toxicity of nimotuzumab in combination with chemoradiotherapy or chemoradiotherapy alone in the treatment of cervical cancer.MethodsThe PubMed, Embase, Cochrane Library, Web of Science, China National Knowledge Infrastructure, China Biomedical Medicine, Wanfang, and VIP databases were systematically searched for relevant literature. Ultimately, six randomised controlled trials (n=393) were included in our meta-analysis.ResultsA total of 393 patients were included, of which 197 were in the nimotuzumab combined with chemoradiotherapy group and 196 were in the chemoradiotherapy group. The results of our meta-analysis showed that the complete remission rate (risk ratio [RR] = 1.34, 95% confidence interval [CI]: 1.08-1.65, P = 0.007), objective response rate (RR = 1.30, 95% CI: 1.16-1.44, P ConclusionsNimotuzumab in combination with chemoradiotherapy has some advantages over chemoradiotherapy alone in the treatment of cervical cancer and does not increase toxicity. Therefore, nimotuzumab has the potential to be an effective treatment for cervical cancer; however, further evidence from large-scale randomised controlled trials is needed.</p

Broncho-Vaxom Attenuates Allergic Airway Inflammation by Restoring GSK3β-Related T Regulatory Cell Insufficiency

<div><p>Background</p><p>Oral administration of bacterial extracts (eg, Broncho-Vaxom (BV)) has been proposed to attenuate asthma through modulating Treg cells. However, the underlying mechanism has not been fully characterized. This study sought to assess the effects of oral administration of BV on GSK-3β expression and Treg cells in ovalbumin (OVA)-induced asthmatic mice models.</p><p>Method</p><p>Asthmatic mice models were established with OVA challenge and treated with oral administration of BV. Next, infiltration of inflammatory cells including eosinophil and neutrophils, mucous metaplasia, levels of Th1/Th2/Treg-typed cytokines and expression of GSK3β and Foxp3 were examined in asthmatic mice models by histological analysis, Bio-Plex and western blot, respectively. Moreover, the frequencies of Treg cells were evaluated in cultured splenocytes by flow cytometry in the presence of BV or GSK3β siRNA interference.</p><p>Results</p><p>We found significant decrease of infiltrated inflammatory cells in bronchoalveolar lavage fluid (BALF) in asthmatic mice models after oral administration of BV. Oral administration of BV was shown to significantly suppress mucus metaplasia, Th2-typed cytokine levels and GSK3β expression while increasing Foxp3 production in asthmatic mice models. Moreover, BV significantly enhanced GSK3β-related expansion of Treg cells in cultured spleen cells <i>in vitro</i>.</p><p>Conclusion</p><p>Our findings provide evidence that oral administration of BV is capable of attenuating airway inflammation in asthmatic mice models, which may be associated with GSK3β-related expansion of Treg cells.</p></div

Oral administration of BV decreased infiltrated inflammatory cells in BALF of asthmatic mice models.

<p>(A), Representative results of infiltrated inflammatory cells in BALF of asthmatic mice models, as suggested by Diff-quick staining. (B), The infiltrated eosinophils, neutrophils and other inflammatory cells were significantly decreased in BALF of asthmatic mice models in 2 monBV/OVA/OVA group. The total inflammation cells and eosinophils in each sample were counted at 5 high power fields (HPFs) and averaged (magnification ×400) (n = 6). ND, no detection. Each sample was tested for 3 times and averaged, all values were expressed as mean ± SD. * <i>P</i><0.05.</p

Oral administration of BV modulated GSK3β and Foxp3 expression in the pulmonary tissues of asthmatic mice models.

<p>(A), Representative immunohistochemical results of GSK3β and Foxp3 expression in the pulmonary tissues of asthmatic mice models (magnification ×400). (B), Oral administration of BV significantly decreased the ratio of GSK3β⁺ cells, but increased the ratio of Foxp3⁺ cells, in the pulmonary tissues of asthmatic mice models in 2 monBV/OVA/OVA group, as indicated by integrated optical density (n = 6). (C), The mRNA expression levels of GSK3β and Foxp3 were showed by RT-QPCR, when normalized by GAPDH and compared with PBS/PBS/PBS group. Each sample was tested for 3 times and averaged, all values were expressed as mean ± SD. * <i>P</i><0.05.</p

Nanoscale Mobility of Aqueous Polyacrylic Acid in Dental Restorative Cements

Hydrogen dynamics in a time range from hundreds of femtoseconds to nanoseconds can be directly analyzed using neutron spectroscopy, where information on the inelastic and quasi-elastic scattering, hereafter INS and QENS, can be obtained. In this study, we applied these techniques to understand how the nanoscale mobility of the aqueous solution of polyacrylic acid (PAA) used in conventional glass ionomer cements (GICs) changes under confinement. Combining the spectroscopic analysis with calorimetric results, we were able to separate distinct motions within both the liquid and the GICs. The QENS analysis revealed that the self-diffusion translational motion identified in the liquid is also visible in the GIC. However, as a result of the formation of the cement matrix and its setting, both translational diffusion and residence time differed from the PAA solution. When comparing the local diffusion obtained for the selected GIC, the only noticeable difference was observed for the slow dynamics associated with the polymer chain. Additionally, over short-term aging, progressive water binding to the polymer chain occurred in one of the investigated GICs. Finally, a considerable change in the density of the GIC without progressive water binding indicates an increased polymer cross-linking. Taken together, our results suggest that accurate and deep understanding of polymer–water binding, polymer cross-linking, as well as material density changes occurring during the maturation process of GIC are necessary for the development of advanced dental restorative materials

Oral administration of BV attenuated allergic airway inflammation and mucous metaplasia in asthmatic mice models.

<p>(A), Representative histological results of pulmonary tissues in asthmatic mice models, as suggested by HE and PAS stainings (magnification ×400). (B), The toal number of eosinophils and mean number of PAS-positive cells in the pulmonary tissues in 2 monBV/OVA/OVA group, as counted at 5 high power fields (magnification ×400) (n = 6). Each sample was tested for 3 times and averaged, all values were expressed as mean ± SD. **<i>P</i><0.01. * <i>P</i><0.05.</p

Experimental protocol for different groups of asthmatic mice models.

<p>The OVA-sensitized and challenged group: mice were sensitized on days 1, 3, 5, 7, 9, 11 and 13 by i.p. injection of 40 μg OVA plus 5 mg Al(OH)₃. One week later, mice were challenged with 5% OVA aerosol inhalation (Compressing Nebulizer, Yuyue, China) for 30 minutes on 7 consecutive days (between day 21 to day 27). PBS was used for oral administration before OVA sensitization and challenge.</p