Effectiveness of first and second boost COVID-19 vaccination in healthy adults during BA.5.2/BF.7 surge in China.

With the development of the SARS-CoV-2 pandemic, there have been doubts about the necessity of vaccine boosters for healthy adults. However, due to the lack of relevant evidence, current research is unable to provide reliable medical advice for COVID-19 boost in healthy adults. We conducted a retrospective observational study to evaluate the effectiveness of different COVID-19 vaccination regimens by investigating the SARS-CoV-2 infection status of healthy donors in Southeast China.

Influence of sodium-modified Ni/SiO catalysts on the tunable selectivity of CO hydrogenation: Effect of the CH selectivity, reaction pathway and mechanism on the catalytic reaction.

CO hydrogenation over Ni/SiO catalysts with and without Na additives was investigated in terms of the catalytic activity, selectivity of CO methanation and reaction mechanism. Na additives could cause the formation of NaO species that might deposit on the Ni surface of Ni/SiO (NiNa/SiO). When the Ni metal is partially covered with NaO species, a highly positive charge on the Ni metal could occur compared to the original Ni/SiO catalyst.

Tiny Ni particles dispersed in platelet SBA-15 materials induce high efficiency for CO methanation.

In this study, short-channel SBA-15 with a platelet morphology (p-SBA-15) is used to support Ni to effectively enhance catalytic activity and CH selectivity during CO hydrogenation. The use of p-SBA-15 as a support can result in smaller Ni particle sizes than Ni particles on typical SBA-15 supports because p-SBA-15 possesses a larger surface area and a greater ability to provide metal-support interactions. The Ni/p-SBA-15 materials with tiny Ni particles exhibit enhanced catalytic activity toward CO hydrogenation and CH formation during CO hydrogenation compared to the same Ni loading on a SBA-15 support.

Synthesis of sub-nanosized Pt particles on mesoporous SBA-15 material and its application to the CO oxidation reaction.

In this work, we show that the size and shape of Pt nanoparticles in SBA-15 can be controlled through vacuum and air calcination. The vacuum-calcination/H2-reduction process is used to thermally treat a 0.2 wt% Pt(4+)/SBA-15 sample to obtain small 2D clusters and single atoms that can significantly increase Pt dispersion in SBA-15.