Immune Protection Induced on Day 10 Following Administration of the 2009 A/H1N1 Pandemic Influenza Vaccine

BACKGROUND: The 2009 swine-origin influenza virus (S-OIV) H1N1 pandemic has caused more than 18,000 deaths worldwide. Vaccines against the 2009 A/H1N1 influenza virus are useful for preventing infection and controlling the pandemic. The kinetics of the immune response following vaccination with the 2009 A/H1N1 influenza vaccine need further investigation. METHODOLOGY/PRINCIPAL FINDINGS: 58 volunteers were vaccinated with a 2009 A/H1N1 pandemic influenza monovalent split-virus vaccine (15 µg, single-dose). The sera were collected before Day 0 (pre-vaccination) and on Days 3, 5, 10, 14, 21, 30, 45 and 60 post vaccination. Specific antibody responses induced by the vaccination were analyzed using hemagglutination inhibition (HI) assay and enzyme-linked immunosorbent assay (ELISA). After administration of the 2009 A/H1N1 influenza vaccine, specific and protective antibody response with a major subtype of IgG was sufficiently developed as early as Day 10 (seroprotection rate: 93%). This specific antibody response could maintain for at least 60 days without significant reduction. Antibody response induced by the 2009 A/H1N1 influenza vaccine could not render protection against seasonal H1N1 influenza (seroconversion rate: 3% on Day 21). However, volunteers with higher pre-existing seasonal influenza antibody levels (pre-vaccination HI titer ≥1∶40, Group 1) more easily developed a strong antibody protection effect against the 2009 A/H1N1 influenza vaccine as compared with those showing lower pre-existing seasonal influenza antibody levels (pre-vaccination HI titer <1∶40, Group 2). The titer of the specific antibody against the 2009 A/H1N1 influenza was much higher in Group 1 (geometric mean titer: 146 on Day 21) than that in Group 2 (geometric mean titer: 70 on Day 21). CONCLUSIONS/SIGNIFICANCE: Recipients could gain sufficient protection as early as 10 days after vaccine administration. The protection could last at least 60 days. Individuals with a stronger pre-existing seasonal influenza antibody response may have a relatively higher potential for developing a stronger humoral immune response after vaccination with the 2009 A/H1N1 pandemic influenza vaccine

Highly Enhanced OER Performance by Er-Doped Fe-MOF Nanoarray at Large Current Densities

Great expectations have been held for the electrochemical splitting of water for producing hydrogen as a significant carbon-neutral technology aimed at solving the global energy crisis and greenhouse gas issues. However, the oxygen evolution reaction (OER) process must be energetically catalyzed over a long period at high output, leading to challenges for efficient and stable processing of electrodes for practical purposes. Here, we first prepared Fe-MOF nanosheet arrays on nickel foam via rare-earth erbium doping (Er0.4 Fe-MOF/NF) and applied them as OER electrocatalysts. The Er0.4 Fe-MOF/NF exhibited wonderful OER performance and could yield a 100 mA cm−2 current density at an overpotential of 248 mV with outstanding long-term electrochemical durability for at least 100 h. At large current densities of 500 and 1000 mA cm−2, overpotentials of only 297 mV and 326 mV were achieved, respectively, revealing its potential in industrial applications. The enhancement was attributed to the synergistic effects of the Fe and Er sites, with Er playing a supporting role in the engineering of the electronic states of the Fe sites to endow them with enhanced OER activity. Such a strategy of engineering the OER activity of Fe-MOF via rare-earth ion doping paves a new avenue to design other MOF catalysts for industrial OER applications

Synthesis, Characterization and Electrochemical Properties of Stable Osmabenzenes Containing PPh3 Substituents

Treatment of [OsCl2(PPh3)(3)] with HC CCH(OH)C=CH/PPh3 produces the osmabenzene [Os{CHC(PPh3)CHC(PPh3)CH}Cl-2(PPh3)(2)][OH] (2), which is air stable in both solution and solid state. The key intermediate of the one-pot reaction, [OSCl2{CH=C(PPh3)CH(OH)C CH}(PPh3)(2)] (3), and the related complex [Os(NCS)(2){CHC(PPh3)CH(OH)C CH}(PPh3)(2)] (7) have been isolated and characterized, further supporting the proposed mechanisms for the reaction. Reactions of 3 with PPh3, NaI, and NaSCN give osmabenzene 2, iodo-substituted osmabenzene [Os{CHC(PPh3)CHCICH}I-2-(PPh3)(2)] (4), and thiocyanato-substituted osmabenzene [Os[CHC(PPh3)CHC(SCN)CH}(NCS)(2)(PPh3)(2)] (5) respectively. Similarly, reaction of [OsBr2(PPh3)(3)] with HC CCH(OH)C CH in THF produces [OsBr2{CH=C(PPh3)CH(OH)C CH)(PPh3)(2)] (9), which reacts with PPh3/Bu4NBr to give osmabenzene [Os{CHC)PPh3)CHC(PPh3)CH}Br(PPh3)(2)]Br (10). Ligand substitution reactions of 2 produce a series of new stable osmabenzenes 11-17. An electrochemical study shows that osmabenzenes 2, 12, and 14-17 have interesting different electrochemical properties due to the different coligand. The oxidation potentials of complexes 2, 12, 16, and 17 with Cl, NCS, and N(CN)(2) ligands gradually positively shift in the sequence of Cl < NCS < N(CN)(2). Among the six compounds, only 12 and 17 undergo a well-behaved, nearly reversible and a quasi-reversible reduction process, respectively, indicating that two NCS or N(CN)(2) ligands contribute to the stabilization of their reduced states.National Science Foundation of China [20572089

Synthesis, Characterization and Electrochemical Properties of Stable Osmabenzenes Containing PPh3 Substituents

Treatment of [OsCl2(PPh3)(3)] with HC CCH(OH)C=CH/PPh3 produces the osmabenzene [Os{CHC(PPh3)CHC(PPh3)CH}Cl-2(PPh3)(2)][OH] (2), which is air stable in both solution and solid state. The key intermediate of the one-pot reaction, [OSCl2{CH=C(PPh3)CH(OH)C CH}(PPh3)(2)] (3), and the related complex [Os(NCS)(2){CHC(PPh3)CH(OH)C CH}(PPh3)(2)] (7) have been isolated and characterized, further supporting the proposed mechanisms for the reaction. Reactions of 3 with PPh3, NaI, and NaSCN give osmabenzene 2, iodo-substituted osmabenzene [Os{CHC(PPh3)CHCICH}I-2-(PPh3)(2)] (4), and thiocyanato-substituted osmabenzene [Os[CHC(PPh3)CHC(SCN)CH}(NCS)(2)(PPh3)(2)] (5) respectively. Similarly, reaction of [OsBr2(PPh3)(3)] with HC CCH(OH)C CH in THF produces [OsBr2{CH=C(PPh3)CH(OH)C CH)(PPh3)(2)] (9), which reacts with PPh3/Bu4NBr to give osmabenzene [Os{CHC)PPh3)CHC(PPh3)CH}Br(PPh3)(2)]Br (10). Ligand substitution reactions of 2 produce a series of new stable osmabenzenes 11-17. An electrochemical study shows that osmabenzenes 2, 12, and 14-17 have interesting different electrochemical properties due to the different coligand. The oxidation potentials of complexes 2, 12, 16, and 17 with Cl, NCS, and N(CN)(2) ligands gradually positively shift in the sequence of Cl < NCS < N(CN)(2). Among the six compounds, only 12 and 17 undergo a well-behaved, nearly reversible and a quasi-reversible reduction process, respectively, indicating that two NCS or N(CN)(2) ligands contribute to the stabilization of their reduced states.National Science Foundation of China [20572089

A metallanaphthalyne complex from zinc reduction of a vinylcarbyne complex

Cl prevents insertion: The first metallanaphthalyne 2 has been obtained by Zn reduction of Os carbyne complex 1. The key to its isolation was the use of o-chlorophenyl instead of phenyl substituents to avoid formation of a putative hydrido metallanaphthalyne intermediate (supported by DFT calculations), which undergoes migratory insertion of the carbyne into the Os-H bond and rearrangement to give an indenyl complex as the final product. (Chemical Equation Presented). © 2007 Wiley-VCH Verlag GmbH & Co. KGaA

Synthesis and Reactivities of Polyhydrido Osmium Arylsilyl Complexes Prepared from OsH₃Cl(PPh₃)₃

Reactions of silanes with transition-metal complexes are of interest because their relevance to Si–H bond activation, the structural properties of polyhydrides, and catalytic hydrosilylation reactions. This work presents the results derived from reactions of arylsilanes Ph₂SiH₂ and PhSiH₃ with OsH₃Cl­(PPh₃)₃ (<b>1</b>). Reaction of <b>1</b> with 1 equiv or excess Ph₂SiH₂ affords OsH₃(SiClPh₂)­(PPh₃)₃ (<b>2</b>) or OsH₄(SiClPh₂)­(SiHPh₂)­(PPh₃)₂ (<b>3</b>), respectively. These silyl complexes are formed via the oxidative addition of Si–H bonds and H/Cl exchange via silylene intermediates. Similarly, reaction of <b>1</b> with excess PhSiH₃ produced the analogous bis­(silyl) complex OsH₄(SiClHPh)­(SiH₂Ph)­(PPh₃)₂ (<b>4</b>). The bis­(silyl) complexes are dodecahedral tetrahydride complexes containing weak Si···H interactions. The complex <b>3</b> reacts with PPh₃ and CH₃CN to selectively eliminate Ph₂SiH₂. Computational studies show that the preference for reductive eliminations from <b>3</b> follows the order Ph₂SiH₂ > H₂ > Ph₂SiHCl > Ph₂HSi-SiClPh₂