Oral Proton Pump Inhibitors May Be as Effective as Intravenous in Peptic Ulcer Bleeding: A Systematic Review and Meta-analysis.

INTRODUCTION: Current guidelines recommend intravenous (IV) proton pump inhibitor (PPI) therapy in peptic ulcer bleeding (PUB). We aimed to compare the efficacy of oral and IV administration of PPIs in PUB. METHODS: We performed a systematic search in 4 databases for randomized controlled trials, which compared the outcomes of oral PPI therapy with IV PPI therapy for PUB. The primary outcomes were 30-day recurrent bleeding and 30-day mortality. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated for dichotomous outcomes, while weighted mean differences (WMDs) with CI were calculated for continuous outcomes in meta-analysis. The protocol was registered a priori onto PROSPERO (CRD42020155852). RESULTS: A total of 14 randomized controlled trials reported 1,951 peptic ulcer patients, 977 and 974 of which were in the control and intervention groups, respectively. There were no statistically significant differences between oral and IV administration regarding 30-day rebleeding rate (OR = 0.96, CI: 0.65-1.44); 30-day mortality (OR = 0.70, CI: 0.35-1.40); length of hospital stay (WMD = -0.25, CI: -0.93 to -0.42); transfusion requirements (WMD = -0.09, CI: -0.07 to 0.24); need for surgery (OR = 0.91, CI: 0.40-2.07); further endoscopic therapy (OR = 1.04, CI: 0.56-1.93); and need for re-endoscopy (OR = 0.81, CI: 0.52-1.28). Heterogeneity was negligible in all analysis, except for the analysis on the length of hospitalization (I2 = 82.3%, P = 0.001). DISCUSSION: Recent evidence suggests that the oral administration of PPI is not inferior to the IV PPI treatment in PUB after endoscopic management, but further studies are warranted.

Prevention of the Aggregation of Nanoparticles during the Synthesis of Nanogold-Containing Silica Aerogels.

Nanogold is widely used in many areas of physics and chemistry due to its environment-sensitive plasmon resonance absorption. The immobilization of gold nanoparticles in highly porous silica aerogel offers an attractive alternative to liquid gold solutions as they show a mechanically stable structure, are permeable to gases, and can even be used at elevated temperatures. We have found that the commercially available citrate-stabilized 10 nm gold nanoparticles may suffer from aggregation prior to or under the base-catalyzed gelation process of tetramethoxy silane. In the wet gels, Au particles increased in size, changed shape, and demonstrated the loss of plasmon resonance absorption, due to the formation of larger aggregates. We have studied a range of water-miscible organic solvents, stabilizing agents, and the gelation conditions to minimize changes from occurring in the aerogel setting and the supercritical drying process. It has been found that atmospheric carbon dioxide has a significant effect on aggregation, and it cannot be entirely excluded under normal synthetic conditions. Methanol resulted in an increase in the particle size only, while dimethyl sulfoxide, dimethylformamide, and urea changed the shape of nanoparticles to rod-like shapes, and diols led to an increase in both size and shape. However, using the polymeric stabilizer poly(vinyl pyrrolidone) efficiently prevented the aggregation of the particles, even in the presence of high concentrations of carbon dioxide, and allowed the production of nanoAu containing silica aerogels in a single step, without the modification of technology.