Incommensurate spin order in the metallic perovskite MnVO3

Incommensurate Mn spin order has been discovered in the perovskite MnVO3 containing localized 3d5 Mn2+ and itinerant 3d1 V4+ states. This phase has a distorted Pnma crystal structure (a = 5.2741(6) Å, b = 7.4100(11) Å, and c = 5.1184(8) Å at 300 K) and is metallic at temperatures of 2-300 K and at pressures of up to 67 kbar. Neutron scattering reveals a (0.29 0 0) magnetic vector below the 46 K spin ordering transition, and both helical and spin density wave orderings are consistent with the diffraction intensities. Electronic structure calculations show large exchange splittings of the Mn and V 3d bands, and (kx 0 0) crossings of the Fermi energy by spin up and down V 3d bands may give rise to Ruderman-Kittel-Kasuya-Yosida coupling of Mn moments, in addition to their superexchange interactions. © 2011 American Physical Society

Kinetics and Cluster Morphology Evolution of Shear-Driven Aggregation of Well-Stabilized Colloids

We investigate the shear-driven aggregation of polystyrene colloids that are stabilized by both fixed and surfactant charges, using a microchannel device, in various particle volume fractions. The objective is to understand how the primary particles evolve to clusters with shearing time, how the cluster morphology develops along the aggregation with the effect of breakage and restructuring, and whether non-Derjaguin–Landau–Verwey–Overbeek (DLVO) interactions are present, affecting the kinetics. The time evolution of the primary particle conversion to big clusters is characterized by an induction time, followed by an explosive increase when the cluster size reaches a certain critical value, which confirms the self-acceleration kinetics developed in the literature. The size of the critical clusters has been quantified for the first time, and its scaling with the shear rate follows the literature prediction well. Moreover, analysis of the shear-driven kinetics confirms the presence of substantial non-DLVO interactions in the given system

Direct Access to Enantioenriched Spiroacetals through Asymmetric Relay Catalytic Three-Component Reaction

The gold(I)/chiral Brønsted acid relay catalysis enabled a highly stereoselective three-component reaction of salicylaldehydes, anilines, and alkynols to give aromatic spiroacetals in high yields and stereoselectivities

Direct Access to Enantioenriched Spiroacetals through Asymmetric Relay Catalytic Three-Component Reaction

The gold(I)/chiral Brønsted acid relay catalysis enabled a highly stereoselective three-component reaction of salicylaldehydes, anilines, and alkynols to give aromatic spiroacetals in high yields and stereoselectivities

Effect of Dispersed Polymeric Nanoparticles on the Bulk Polymerization of Methyl Methacrylate

We proposed a methodology to investigate the effect of dispersed nanoparticles (NPs) on bulk polymerization of methyl methacrylate (MMA), based on DSC experiments and modeling of the bulk polymerization kinetics. As examples, we have applied it to polymeric NPs, polytetra­fluoroethylene (PTFE) and polystyrene (PS), and compared the results with those from linear PMMA and cross-linked PMMA (cPMMA). The presence of dissolved linear PMMA enhances the MMA bulk polymerization kinetics, as if the system was prepolymerized at a conversion equal to the dissolved amount of the linear PMMA. The dispersed cPMMA also enhances the MMA polymerization kinetics, but the enhancement decreases as the cross-linker in the cPMMA increases. The PTFE NPs behave like (inert) dead volume, while the PS NPs do enhance the MMA polymerization kinetics due to their slight swelling in MMA. Therefore, we can conclude that dispersed nonswellable polymeric NPs behave like inert dead volume, and swellable polymeric NPs enhance the MMA bulk polymerization kinetics and the enhancement extent increases as the swelling extent increases. The CryoSEM image of the bulk PMMA shows grainlike microstructure when the NPs are present

Immunofluorescence staining under confocal microscopy.

<p>Neutrophils challenged by cKP (9 isolates, A-D) and HvKP-K1 (9 isolates, E-H) were stained for DNA (DAPI, blue, A and E), myeloperoxidase (MPO, red, B and F) and citrullinated histone H3 (cit-H3, green, C and G). The merged images of cKP (D) and HvKP-K1 (H) illustrated the characteristic neutrophil extracellular traps. Original magnification 40×.</p

Phagocytosis of neutrophils against HvKP-K1, HvKP-K2 and cKP.

<p>The rate of phagocytosis against cKP (15 isolates) was higher than that against HvKP-K1 (16 isolates) or HvKP-K2 (14 isolates) at 10, 30, 60 min. The mean ± standard deviation (S.D.) of each group at each time point was calculated respectively. Statistics was performed using one-way analysis of variance for each time point. Differences between groups were assessed by <i>t</i> test. At 10, 30, 60 min, HvKP-K1 vs. cKP or HvKP-K2 vs. cKP: p < 0.05.</p

NETs under scanning electron microscopy.

<p>NETs induced by PMA (A and B), cKP (3 isolates, C and D), and HvKP-K1 (3 isolates, E and F). More cKP (C) than HvKP-K1 (E) were trapped in NETs by magnification of 5K. The pores (indicated by white arrows) on the surface of cKP, but not on the surface of HvKP-K1 were observed by magnification of 20K (D and F). Bacteria were indicated by black arrows.</p

Survival of cKP, HvKP-K1 and HvKP-K2 within human neutrophils.

<p>The survival index was calculated with the equation described in the method. The survival index of cKP (15 isolates) was lower than that of HvKP-K1 (16 isolates) or HvKP-K2 (14 isolates). Each strain was repeated twice and averaged. Then the mean ± standard deviation (S.D.) of each group was calculated. Statistics was performed using one-way analysis of variance. Differences between groups were assessed by <i>t</i> test. HvKP-K1 vs. cKP or HvKP-K2 vs. cKP: p < 0.001.</p

Forest plot of late xerostomia in HNSCC patients treated with radiotherapy/concomitant chemoradiation.

<p>The squares and horizontal lines demonstrate the study-specific OR and 95% CI. The area of the squares reflects the study specific weight (inverse of the variance). The diamond represents the pooled OR and 95% CI.</p