Lithium dibenzoylphosphide · 1,2-Dimethoxyethane : a new 2-phospha-1,3-dionate

The lithium compound (1) was formed in place of dibenzoylphosphane on reaction of LiPH2 DME with PhCOCl. In its crystal, (1) exists as a dimer having a four-membered (LiOLiO) ring and pentacoordinated lithium

Lithiumdibenzoylphosphid·1,2-Dimethoxyethan, ein neues 2-Phospha-1,3-dionat

Die Lithiumverbindung (1) anstelle von Dibenzoylphosphan, entstand bei der Umsetzung von LiPH2 · DME mit PhCOCl. Im Kristall existiert (1) als Dimer mit (LiOLiO)-Vierring und pentakoordiniertem Lithium

Stabilizing a metalloid Zn12_{12} unit within a polymetallide environment in [K2_{2}Zn20_{20}Bi16_{16}]6−^{6-}

The access to molecules comprising direct Zn–Zn bonds has become very topical in recent years for various reasons. Low-valent organozinc compounds show remarkable reactivities, and larger Zn–Zn-bonded gas-phase species exhibit a very unusual coexistence of insulating and metallic properties. However, as Zn atoms do not show a high tendency to form clusters in condensed phases, synthetic approaches for generating purely inorganic metalloid Zn$_{x}$ units under ambient conditions have been lacking so far. Here we show that the reaction of a highly reductive solid with the nominal composition K$_{5}$Ga$_{2}$Bi$_{4}$ with ZnPh2 at room temperature yields the heterometallic cluster anion [K$_{2}$Zn$_{20}$Bi$_{16}$]$^{6-}$. A 24-atom polymetallide ring embeds a metalloid {Zn$_{12}$} unit. Density functional theory calculations reveal multicenter bonding, an essentially zero-valent situation in the cluster center, and weak aromaticity. The heterometallic character, the notable electron-delocalization, and the uncommon nano-architecture points at a high potential for nano-heterocatalysis

(2E,6E)-2,6-Bis(4-methyl­benzyl­idene)cyclo­hex-3-en-1-one

The title compound, C22H20O, shows an approximately planar cyclo­hexenone ring [maximum deviation = 0.069 (4) Å], with a disordered position of the C=C bond [ratio = 0.71 (2)/0.29 (2)]. The benzene rings of the 4-methyl­benzyl­idene units, attached in the 2- and 6-positions to the cyclo­hexenone ring, are rotated in the same direction by 28.6 (4) and 22.4 (4)°, with respect to the mean plane of the cyclo­hexenone ring [fraction 0.71 (2); maximum deviation = 0.06 (3) Å]. In the crystal, mol­ecules are packed in the manner of a distorted hexa­gonal rod packing with their long axes all aligned along [201]. A number of C—H⋯π inter­actions stablize the crystal structure

(4Z,6Z)-4,6-Bis(4-meth­oxy­benzyl­idene)-2,2-dimethyl-1,3-dioxan-5-one

The title compound, C22H22O5, crystallizes with two independent mol­ecules in the asymmetric unit, both of which possess pseudo-C s symmetry. The central 1,3-dioxanone rings have envelope conformations, with the C atom bearing the two methyl groups at the flap. The benzene rings of the meth­oxy­benzyl­idene units, attached in the 4- and 6-positions on the central 1,3-dioxanone rings, are tilted in the same direction with dihedral angles varying between 8.2 (1) and 18.1 (1)°. The crystal packing is influenced by π-stacking inter­actions of the parallel displaced type [centroid–centroid distance of 3.723 (1) Å for mol­ecule 1 and 3.884 (1) Å for mol­ecule 2, with ring slippages of 1.432 and 1.613 Å, respectively] and the T-shaped type, with the long mol­ecular axes all aligned along [010]

MOST detects corotating bright spots on the mid-O type giant {\xi} Persei

We have used the MOST (Microvariability and Oscillations of STars) microsatellite to obtain four weeks of contiguous high-precision broadband visual photometry of the O7.5III(n)((f)) star {\xi} Persei in November 2011. This star is well known from previous work to show prominent DACs (Discrete Absorption Components) on time-scales of about 2 d from UV spectroscopy and NRP (Non Radial Pulsation) with one (l = 3) p-mode oscillation with a period of 3.5 h from optical spectroscopy. Our MOST-orbit (101.4 min) binned photometry fails to reveal any periodic light variations above the 0.1 mmag 3-sigma noise level for periods of hours, while several prominent Fourier peaks emerge at the 1 mmag level in the two-day period range. These longer-period variations are unlikely due to pulsations, including gravity modes. From our simulations based upon a simple spot model, we deduce that we are seeing the photometric modulation of several co-rotating bright spots on the stellar surface. In our model, the starting times (random) and lifetimes (up to several rotations) vary from one spot to another yet all spots rotate at the same period of 4.18 d, the best-estimated rotation period of the star. This is the first convincing reported case of co-rotating bright spots on an O star, with important implications for drivers of the DACs (resulting from CIRs - Corotating Interaction Regions) with possible bright-spot generation via a breakout at the surface of a global magnetic field generated by a subsurface convection zone.Comment: 9 pages, 4 figures, 2 tables, MNRAS in pres

Mid-Infrared Properties of the Swift Burst Alert Telescope Active Galactic Nuclei Sample of the Local Universe. I. Emission-Line Diagnostics

We compare mid-infrared emission-line properties, from high-resolution Spitzer spectra of a hard X-ray (14 -- 195 keV) selected sample of nearby (z < 0.05) AGN detected by the Burst Alert Telescope (BAT) aboard Swift. The luminosity distribution for the mid-infrared emission-lines, [O IV] 25.89 micron, [Ne II] 12.81 micron, [Ne III] 15.56 micron and [Ne V] 14.32/24.32 micron, and hard X-ray continuum show no differences between Seyfert 1 and Seyfert 2 populations, however six newly discovered BAT AGNs are under-luminous in [O IV], most likely the result of dust extinction in the host galaxy. The overall tightness of the mid-infrared correlations and BAT fluxes and luminosities suggests that the emission lines primarily arise in gas ionized by the AGN. We also compare the mid-infrared emission-lines in the BAT AGNs with those from published studies of ULIRGs, PG QSOs, star-forming galaxies and LINERs. We find that the BAT AGN sample fall into a distinctive region when comparing the [Ne III]/[Ne II] and the [O IV]/[Ne III] ratios. These line ratios are lower in sources that have been previously classified in the mid-infrared/optical as AGN than those found for the BAT AGN, suggesting that, in our X-ray selected sample, the AGN represents the main contribution to the observed line emission. These ratios represent a new emission line diagnostic for distinguishing between AGN and star forming galaxies.Comment: 54 pages, 9 Figures. Accepted for publication in The Astrophysical Journal

The Biological Connection Markup Language: a SBGN-compliant format for visualization, filtering and analysis of biological pathways

Motivation: Many models and analysis of signaling pathways have been proposed. However, neither of them takes into account that a biological pathway is not a fixed system, but instead it depends on the organism, tissue and cell type as well as on physiological, pathological and experimental conditions

Circulating Apoptotic Progenitor Cells in Patients with Congestive Heart Failure

Background: Circulating CD34+ endothelial progenitor cells (EPCs) are capable of differentiating into mature endothelial cells to assist in angiogenesis and vasculogenesis. We sought to quantify the numbers of apoptotic progenitors in patients with congestive heart failure. Methods and Results: Peripheral blood mononuclear cells were isolated by Ficoll density-gradient from 58 patients with various degrees of heart failure and 23 matched controls. Apoptosis in progenitor CD34+ cells was assessed using the Annexin V-PE/PI detection kit, and FACS analysis was performed with triple staining for CD34, annexin-V and propidium iodide. The percentage of early and late apoptotic progenitor cells was determined in the subject groups and was correlated with clinical characteristics. While there was no significant difference in total CD34 positive cells or early apoptotic progenitors between control subjects and CHF patients (p = 0.42) or between severe and mild/moderate CHF groups (p = 0.544), there was an elevated number of late apoptotic progenitors in the severe CHF group compared with the mild/moderate CHF group (p = 0.03). Late apoptotic progenitors were significantly increased in CHF patients as compared to matched controls. There was also an inverse correlation between late apoptotic progenitors and ejection fraction (r = 20.252, p = 0.028) as well as a positive association with NYHA class (r = 0.223, p = 0.046). Conclusion: Severe heart failure patients exhibited higher numbers of late apoptotic progenitors, and this was positivel