PIKA Provides an Adjuvant Effect to Induce Strong Mucosal and Systemic Humoral Immunity Against SARS-CoV

Severe Acute Respiratory Syndrome （SARS） is a deadly infectious disease caused by SARS Coronavirus （SARS-CoV）. Inactivated SARS-CoV has been explored as a vaccine against SARS-CoV. However, safe and potent adjuvants, especially with more efficient and economical needle-free vaccination are alw needed more urgently in a pandemic. The development of a safe and effective mucosal adjuvant and vaccine ays for prevention of emergent infectious diseases such as SARS will be an important advancement. PIKA, a stabilized derivative of Poly （I：C）, was previously reported to be safe and potent as adjuvant in mouse models. In the present study, we demonstrated that the intraperitoneal and intranasal co-administration of inactivated SARS-CoV vaccine together with this improved Poly （I：C） derivative induced strong anti-SARS-CoV mucosal and systemic humoral immune responses with neutralizing activity against pseudotyped virus. Although intraperitoneal immunization of inactivated SARS-CoV vaccine alone could induce a certain level of neutralizing activity in serum as well as in mucosal sites, co-administration of inactivated SARS-CoV vaccine with PIKA as adjuvant could induce a much higher neutralizing activity. When intranasal immunization was used, PIKA was obligatorily for inducing neutralizing activity in serum as well as in mucosal sites and was correlated with both mucosal IgA and mucosal IgG response. Overall, PIKA could be a good mucosal adjuvant candidate for inactivated SARS-CoV vaccine for use in possible future pandemic.

Unraveling the catalytically active phase of carbon dioxide hydrogenation to methanol on Zn/Cu alloy: Single atom versus small cluster

Methanol synthesis from CO_(2)hydrogenation catalyzed by Zn/Cu alloy has been widely studied,but there is still debate on its catalytic active phase and whether the Zn can be oxidized during the reaction process.What is more,as Zn atoms could locate on Zn/Cu alloy surface in forms of both single atom and cluster,how Zn surface distribution affects catalytic activity is still not clear.In this work,we performed a systematic theoretical study to compare the mechanistic natures and catalytic pathways between Zn single atom and small cluster on catalyst surface,where the surface oxidation was shown to play the critical role.Before surface oxidation,the Zn single atom/Cu is more active than the Zn small cluster/Cu,but its surface oxidation is difficult to take place.Instead,after the easy surface oxidation by CO_(2)decomposition,the oxidized Zn small cluster/Cu becomes much more active,which even exceeds the hardlyoxidized Zn single atom/Cu to become the active phase.Further analyses show this dramatic promotion of surface oxidation can be ascribed to the following factors:i)The O from surface oxidation could preferably occupy the strongest binding sites on the center of Zn cluster.That makes the O intermediates bind at the Zn/Cu interface,preventing their too tight binding for further hydrogenation;ii)The higher positive charge and work function on the oxidized surface could also promote the hydrogenation of O intermediates.This work provided one more example that under certain condition,the metal cluster can be more active than the single atom in heterogeneous catalysis.

Pitavastatin calcium improves endothelial function and delays the progress of atherosclerosis in patients with hypercholesterolemia

Background： Statins have proven efficacy in inhibiting the onset and progress of atherosclerosis. The effectiveness of pitavastatin in reversing carotid atherosclerosis associated with hypercholesterolemia （HC） is un-known. Objectives： To explore the simultaneous effects of pitavastatin calcium on brachial arterial flow-mediated vasodilatation （FMD）, carotid intima-media thickness （IMT）, and arterial stiffness （β）, three surrogate markers of ath-erosclerosis were studied in HC patients. Methods：A randomized, double-blind trial was performed with 40 HC sub-jects who fulfil ed the inclusion/exclusion criteria. Patients were given pitavastatin calcium 1 mg/d （Group 1） or 2 mg/d （Group 2） for 8 weeks. There were 20 patients in each group, and 30 gender-and age-matched healthy subjects as controls were recruited. FMD of the brachial artery, carotid IMT, and arterial stiffness indicated byβwere measured at baseline and at 8 weeks after starting pitavastatin calcium therapy using ultrasound techniques. Biochemical tests were also made on al subjects. Results： At baseline, higher total cholesterol （TC） and low-density lipoprotein cho-lesterol （LDL-C）, reduced FMD, and increasedβand IMT were observed in HC patients （P0.05）. Significant negative interactions between TC/LDL and FMD （P〈0.05–0.001）, positive interactions between TC and IMT （P=0.003） and between TC/LDL and β （P〈0.001–0.000） were found. Conclusions： Treatment with pitavastatin calcium exerted fa-vorable effects on endothelial function and arterial stiffness. It also improved carotid atherosclerosis in patients with HC.