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Objective: Proton pump inhibitors (PPIs) are recommended for preventing gastrointestinal lesions induced by non-steroidal anti-inflammatory drugs (NSAIDs). We performed this study: (1) to evaluate the effectiveness and safety of PPIs, (2) to explore the association between effectiveness and potential influential factors, and (3) to investigate the comparative effect of different PPIs. Methods: MEDLINE, EMBASE, and the Cochrane Library were searched to identify randomized controlled trials comparing different classes of PPIs, or comparing PPIs with placebo, H2 receptor antagonists or misoprostol in NSAIDs users. Both pairwise meta-analysis and Bayesian network meta-analysis were performed. Results: Analyses were based on 12,532 participants from 31 trials. PPIs were significantly more effective than placebo in reducing ulcer complications (relative risk [RR] = 0.29; 95% confidence interval [CI], 0.20 to 0.42) and endoscopic peptic ulcers (RR = 0.27; 95% CI, 0.22 to 0.33), with no subgroup differences according to class of NSAIDs, ulcer risk, history of previous ulcer disease, Helicobacter pylori infection, or age. To prevent one ulcer complication, 10 high risk patients and 268 moderate risk patients need PPI therapy. Network meta-analysis indicated that the effectiveness of different PPIs in reducing ulcer complications and endoscopic peptic ulcers is generally similar. PPIs significantly reduced gastrointestinal adverse events and the related withdrawals compared to placebo; there is no difference in safety between different PPIs. Conclusions: PPIs are effective and safe in preventing peptic ulcers and complications in a wide spectrum of patients requiring NSAID therapy. There is no major difference in the comparative effectiveness and safety between different PPIs.

Doping and constructing intergrowth are found to be an effectual approach to modify the electrical properties of bismuth layer-structured ferroelectrics. In this work, ferroelectric, piezoelectric and dielectric properties of Nb-doped Bi4Ti3O12-SrBi4Ti4O15 (BTN-SBTN-x) intergrowth ceramics were investigated. The ferroelectric property of Bi4Ti3O12-SrBi4Ti4O15 was improved by niobium doping. The remanent polarization (2P r ) increases at first, then decreases with the increase of niobium content, while the coercive field changes little with Nb-doping. As niobium content is 0.06, the 2P r maximizes at a value of 34.9 μC/cm2, which is increased by about 75% in comparison with that of Bi4Ti3O12-SrBi4Ti4O15 (2P r = 20.0 μC/cm2). The Curie temperature of the samples varies hardly upon Nb-doping, which indicates that the good thermal stability of Bi4Ti3O12-SrBi4Ti4O15 is not deteriorated after Nb addition. Piezoelectric coefficient d33 was increased from 9.3 pC·N−1 to 18.6 pC·N−1 due to the enlargement ...

Ferroelectric ceramics of lanthanum-modified SrBi4Ti4O15 and Bi4Ti3O12-SrBi4Ti4O15 have been synthesized, and Raman spectrum measurements have been carried out at room temperature. The investigation on the Raman spectra suggest that La3+ ions prefer to occupy the A site in the case of x ≤ 0.10, and at higher content they tend to be incorporated into Bi2O2 layers in the La-doped SrBi4Ti4O15. As for La-doped Bi4Ti3O12-SrBi4Ti4O15, the critical content of the doping ions is 0.50. An interesting phenomenon has been noticed that the remnant polarization maximized at about the critical doping content. Thus, it can be concluded that the Bi2O2 layers have a very important effect on the properties in the bismuth layer-structured ferroelectric materials.

Sr2Bi4Ti5O18 (SBTi) and Sr-deficient SBTi thin films were deposited on Pt/Ti/SiO2/Si(100) substrates using a sol-gel method. Structure, morphology and electric properties were investigated systematically. These films were random-oriented and were composed of rod-like grains. The remanent polarization (2P r ) and coercive field (Ec) of SBTi films were 24 μC/cm2 and 68 kV/cm, respectively. This value of 2P r was much higher than the reported value of SBTi prepared by pulse laser deposition. The compounds with Sr-deficient and Bi-excess composition showed a very large remanent polarization of 35.5 μC/cm2. More importantly, both films showed high fatigue resistance against continuous switching up to 3 × 1010 cycles and excellent charge-retaining ability up to 3 × 104 s.

An investigation on the ferroelectric and dielectric properties of higher-valent-cations Nb-and Mo-modificated SrBi4Ti4O15 ceramics was presented. The ferroelectric property of SrBi4Ti4O15 was both obviously improved by niobium and molybdenum doping. The remnant polarization (2P r ) of both Nb-and Mo-modificated SrBi4Ti4O15 increases at first, then decreases with further doping. As the doping content is 0.03 and 0.06 respectively, the 2P r maximizes at a value of 24.7 μC/cm2 and 26.5 μC/cm2, which is about twice larger than that of SrBi4Ti4O15. Meanwhile, the coercive field is increased less than 20% upon Nb and Mo substitution. The Curie temperature of the samples shifted hardly by Nb-and Mo-doping, which indicates that the good thermal stability of SrBi4Ti4O15 is not affected.