3R-IrO₂ Two-Dimensional Nanosheets with Varying Layer Spacing and [IrO₆] Distortion for OER

Here, two iridium-based crystal structures, K0.3IrO2·xH2O and Rb0.3IrO2·xH2O, have been synthesized for application in the oxygen evolution reaction (OER). The 3R-type layered IrO2 structures with different lattice parameters were successfully obtained from the two Ir structures by the hydrogen ion exchange method. According to synchrotron radiation spectra and the theoretical calculation of density functional theory (DFT), the increase of oxygen vacancy concentration caused by lattice distortion in the 3R-IrO2 crystal is negatively correlated with the activity of OER. A high concentration of oxygen vacancies will reduce Ir–O hybridization, which is not conducive to the balance between the adsorption and desorption of intermediate products. The higher OH adsorption energy barrier and band gap of the 3R-IrO2 crystal limited the improvement of electrochemical performance. In addition, through the analysis of the bonding orbitals and antibonding orbitals of the two structures, we concluded that 3R-IrO2 belongs to the nonthermodynamically stable structure and is not suitable for hydrogen production by electrolysis of water

DataSheet_1_Contrasting patterns of genetic and phenotypic divergence of two sympatric congeners, Phragmites australis and P. hirsuta, in heterogeneous habitats.docx

Habitat heterogeneity leads to genome-wide differentiation and morphological and ecological differentiation, which will progress along the speciation continuum, eventually leading to speciation. Phragmites hirsuta and Phragmites australis are sympatric congeners that coexist in saline-alkaline meadow soil (SAS) and sandy soil (SS) habitats of the Songnen Meadow. The results provided genetic evidence for two separate species of reeds. Genetic diversity and spatial genetic structure supported the specialist-generalist variation hypothesis (SGVH) in these two sympatric reed species, suggesting that P. australis is a generalist and P. hirsuta is a habitat specialist. When we compared these different species with respect to phenotypic and genetic variation patterns in different habitats, we found that the phenotypic differentiation of P. australis between the two habitats was higher than that of P. hirsuta. Multiple subtle differences in morphology, genetic background, and habitat use collectively contribute to ecological success for similar congeners. This study provided evidence of the two reed congeners, which should contribute to their success in harsh environments.</p

Palladium-Catalyzed Oxidative Heck-Type Alkylation/Aryl Migration/Desulfonylation between Alkenes with α‑Carbonyl Alkyl Bromides

A new Pd­(II)-catalyzed alkene oxidative difunctionalization initiated by Heck insertion has been developed for the selective synthesis of acyclic and cyclic all-carbon quaternary stereocenters, which achieves an oxidative Heck-type alkylation, aryl migration, and desulfonylation sequence and represents a different input from those previously used Heck coupling in synthesis is reported

Genetic structure of Tamarix chinensis populations in Yellow River Delta, China

Genetic structure of Tamarix chinensis populations in Yellow River Delta, Chin

Effect of ROD03671

<p><b>and </b><b><i>tad</i></b><b> on the ability of </b><b><i>C. rodentium</i></b><b> to colonize mice.</b> In a competitive infection model, C57/BL6 mice were inoculated by oral gavage with approximately 10⁹ CFU wild-type <i>C. rodentium</i> (▪) and either the ROD03671 mutant, ICA36 (▴) or the <i>tad</i> mutant, ICA38 (○), in a 1∶1 ratio. Results are the mean ± SD of the numbers of the two strains in the colon contents 7 days after inoculation.</p

Pt-Doped NiFe₂O₄ Spinel as a Highly Efficient Catalyst for H₂ Selective Catalytic Reduction of NO at Room Temperature

H₂ selective catalytic reduction (H₂-SCR) has been proposed as a promising technology for controlling NO<i>_x</i> emission because hydrogen is clean and does not emit greenhouse gases. We demonstrate that Pt doped into a nickel ferrite spinel structure can afford a high catalytic activity of H₂-SCR. A superior NO conversion of 96% can be achieved by employing a novel NiFe_1.95Pt_0.05O₄ spinel-type catalyst at 60 °C. This novel catalyst is different from traditional H₂-SCR catalysts, which focus on the role of metallic Pt species and neglect the effect of oxidized Pt states in the reduction of NO. The obtained Raman and XPS spectra indicate that Pt in the spinel lattice has different valence states with Pt²⁺ occupying the tetrahedral sites and Pt⁴⁺ residing in the octahedral ones. These oxidation states of Pt enhance the back-donation process, and the lack of filling electrons of the 5d band causes Pt to more readily hybridize with the 5σ orbital of the NO molecule, especially for octahedral Pt⁴⁺, which enhances the NO chemisorption on the Pt sites. We also performed DFT calculations to confirm the enhancement of adsorption of NO onto Pt sites when doped into the Ni–Fe spinel structure. The prepared Pt/Ni–Fe catalysts indicate that increasing the dispersity of Pt on the surfaces of the individual Ni–Fe spinel-type catalysts can efficiently promote the H₂-SCR activity. Our demonstration provides new insight into designing advanced catalysts for H₂-SCR

T Follicular Helper Cells and Regulatory B Cells Dynamics in Systemic Lupus Erythematosus

<div><p>T follicular helper (Tfh) cells aid effector B cells, and augment autoimmunity, whereas the role of Tfh cells on regulatory B (Breg) cells in systemic lupus erythematosus (SLE) is not known. The aim of this study is to investigate the percentage of Breg cells in SLE, and the role of Tfh cells on Breg cells. First, we demonstrated the presence of Breg cells in SLE peripheral blood mononuclear cells and in involved skins. Both the percentage of circulating Breg cells and the ability to produce interleukin-10 (IL-10) were elevated in SLE patients. The percentage of Breg cells increased during SLE flares and decreased following disease remission. Second, Tfh cell expansion was not only related to autoantibody production but also correlated with the increased percentage of Breg cells. Third, in vitro studies revealed that Tfh cell-derived IL-21 could promote IL-10 production and Breg cell differentiation. In conclusions, these data imply that SLE flares may be linked to the expansion of Tfh cells and that Breg cells are increased in a regulatory feedback manner. Thus, SLE development may be associated with the complex regulation of Tfh cells and diverse B cell subsets.</p></div

Hollandite Structure K_{<i>x</i>≈0.25}IrO₂ Catalyst with Highly Efficient Oxygen Evolution Reaction

Oxygen evolution reaction (OER) catalysts with high activity are of particular importance for renewable energy production and storage. Here, we prepare K_{<i>x</i>≈0.25}IrO₂ catalyst that exhibits an excellent OER activity compared to IrO₂, which is univerally acknoweledged as a state-of-the-art OER catalyst. The prepared catalyst reflects a small overpotential 0.35 V at a current density of 10 mA cm^–2 and a lower Tafel slope (65 mV dec^–1) compared to that for IrO₂ (74 mV dec^–1). The performed X-ray photoelectron spectroscopy (XPS) and X-ray adsorption (XAS) experiments indicate that the Ir-site of K_{<i>x</i>≈0.25}IrO₂ has a lower valence and more Ir-5d occupied states, suggesting more electrons on the Ir site. The extra electrons located on the Ir site and distorted IrO₆ octahedral symmetry have a significant effect on the 5d orbital energy distribution which is verified by our DOS calculation. The performed DFT calculations state that the K_{<i>x</i>≈0.25}IrO₂ essentially obtains good OER performance because it has a lower theoretical overpotential (0.50 V) compared to IrO₂ (0.61 V)

Table1_Thermal properties and kinetic analysis of pyrolysis products of nicotine salts from e-cigarettes using pyrolysis-gas chromatography/mass spectrometry.DOCX

Volatile organic chemicals (VOCs) released from e-cigarettes are a special source of air pollutants. In this work, we investigated the VOCs released from six nicotine salts (namely, nicotine benzoate, nicotine tartrate, nicotine citrate, nicotine malate, nicotine lactate, and nicotine levulinate) that are commonly used in e-cigarettes. The pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) and thermogravimetric methods were used to analyze the thermogravimetric characteristics and product release behavior of different nicotine salts. Moreover, the kinetic models and thermodynamic parameters of nicotine salts during the thermal decomposition process were obtained. Thermogravimetric characteristic parameters of six nicotine salts showed significant differences. By the use of Py-GC/MS, our data showed that the pyrolysis products of nicotine salts were mainly from nicotine, acid anhydrides, carboxylic acids, and N-heterocycles, while more than 90% of the nicotine of citrate, tartrate, and malate was transferred to smoke. The result revealed that activation energies of the nicotine salts range from 21.26 to 74.10 kJ mol-1, indicating that the pyrolysis of the nicotine salts is a non-spontaneous heat absorption process, and the organic acid was the key factor affecting the release of nicotine into the ambient air.</p

Effect of <i>ureB</i> on the ability of <i>C. rodentium</i> ICC169 to colonize mice.

<p>C57/BL6 mice were inoculated by oral gavage with approximately 10¹⁰ CFU of wild-type <i>C. rodentium</i> (▪) or a <i>ureB</i> mutant, ICA32 (▴). Results are the mean ± standard deviation log₁₀ CFU/g feces from at least four mice. The limit of detection was 100 CFU/g feces. *, <i>P</i><0.05; **, <i>P</i><0.005, Student’s t test.</p