Complexes of 3d Metals with a Bulky Carbazolyl Ligand

In this contribution, the synthesis and properties of nine novel 3d metal complexes are reported. As supporting ligand scaffold, the bulky 1,8-bis(3,5-ditertbutylphenyl)-3,6-ditertbutylcarbazole (R) was employed. After deprotonation and salt metathesis reactions, a series of four complexes, the dimeric [RMn(THF)(μ-Cl)]$_{2}$ (1 a), [RFe(THF)(μ-Cl)]$_{2}$ (2 a), and [RCo(THF)(μ-Cl)]$_{2}$ (3 a) as well as a monomeric [RCr(THF)$_{2}$(Cl)] (4 a), were obtained, while the analogous Ni(II) complex remained elusive. However, incorporation of PMe$_{3}$ as stronger donor molecule in comparison sufficed to stabilise also the Ni(II) complex [RNi(PMe$_{3}$)$_{2}$(Cl)] (5 b). The series was completed by treatment of 1 a–4 a with PMe$_{3}$, which afforded the related phosphine complexes 1 b–4 b. All complexes were characterised in the solid state by single crystal structure elucidation and their magnetic moments in solution were determined by NMR experiments with the Evans method

The Multiplicity of M-Dwarfs in Young Moving Groups

We image 104 newly identified low-mass (mostly M-dwarf) pre-main sequence members of nearby young moving groups with Magellan Adaptive Optics (MagAO) and identify 27 binaries with instantaneous projected separation as small as 40 mas. 15 were previously unknown. The total number of multiple systems in this sample including spectroscopic and visual binaries from the literature is 36, giving a raw multiplicity rate of at least $35^{+5}_{-4}\%$ for this population. In the separation range of roughly 1 - 300 AU in which infrared AO imaging is most sensitive, the raw multiplicity rate is at least $24^{+5}_{-4}\%$ for binaries resolved by the MagAO infrared camera (Clio). The M-star sub-sample of 87 stars yields a raw multiplicity of at least $30^{+5}_{-4}\%$ over all separations, $21^{+5}_{-4}\%$ for secondary companions resolved by Clio from 1 to 300 AU ($23^{+5}_{-4}\%$ for all known binaries in this separation range). A combined analysis with binaries discovered by the Search for Associations Containing Young stars shows that multiplicity fraction as a function of mass and age over the range of 0.2 to 1.2 $M_\odot$ and 10 - 200 Myr appears to be linearly flat in both parameters and across YMGs. This suggests that multiplicity rates are largely set by 100 Myr without appreciable evolution thereafter. After bias corrections are applied, the multiplicity fraction of low-mass YMG members ($< 0.6 M_\odot$) is in excess of the field.Comment: 25 page

SerpinB2 regulates stromal remodelling and local invasion in pancreatic cancer

Pancreatic cancer has a devastating prognosis, with an overall 5-year survival rate of ~8%, restricted treatment options and characteristic molecular heterogeneity. SerpinB2 expression, particularly in the stromal compartment, is associated with reduced metastasis and prolonged survival in pancreatic ductal adenocarcinoma (PDAC) and our genomic analysis revealed that SERPINB2 is frequently deleted in PDAC. We show that SerpinB2 is required by stromal cells for normal collagen remodelling in vitro, regulating fibroblast interaction and engagement with collagen in the contracting matrix. In a pancreatic cancer allograft model, co-injection of PDAC cancer cells and SerpinB2(-/-) mouse embryonic fibroblasts (MEFs) resulted in increased tumour growth, aberrant remodelling of the extracellular matrix (ECM) and increased local invasion from the primary tumour. These tumours also displayed elevated proteolytic activity of the primary biochemical target of SerpinB2-urokinase plasminogen activator (uPA). In a large cohort of patients with resected PDAC, we show that increasing uPA mRNA expression was significantly associated with poorer survival following pancreatectomy. This study establishes a novel role for SerpinB2 in the stromal compartment in PDAC invasion through regulation of stromal remodelling and highlights the SerpinB2/uPA axis for further investigation as a potential therapeutic target in pancreatic cancer

Histone deacetylase inhibitors: potential targets responsible for their anti-cancer effect

The histone deacetylase inhibitors (HDACi) have demonstrated anticancer efficacy across a range of malignancies, most impressively in the hematological cancers. It is uncertain whether this clinical efficacy is attributable predominantly to their ability to induce apoptosis and differentiation in the cancer cell, or to their ability to prime the cell to other pro-death stimuli such as those from the immune system. HDACi-induced apoptosis occurs through altered expression of genes encoding proteins in both intrinsic and extrinsic apoptotic pathways; through effects on the proteasome/aggresome systems; through the production of reactive oxygen species, possibly by directly inducing DNA damage; and through alterations in the tumor microenvironment. In addition HDACi increase the immunogenicity of tumor cells and modulate cytokine signaling and potentially T-cell polarization in ways that may contribute the anti-cancer effect in vivo. Here, we provide an overview of current thinking on the mechanisms of HDACi activity, with attention given to the hematological malignancies as well as scientific observations arising from the clinical trials. We also focus on the immune effects of these agents

First light of the VLT planet finder SPHERE IV : Physical and chemical properties of the planets around HR8799

This is a pre-copyedited, author produced PDF of an article accepted for publication in Astronomy & Astrophysics following peer review. Subject to 12 month's embargo period. Embargo end date: 16 February 2017. The version of record [Bonnefoy, M., 'First light of the VLT planet finder SPHERE, IV. Physical and chemical properties of the planets around HR8799', A&A, 587, A58 (2016), first published online 16 February 2016] is available online at doi http://dx.doi.org/10.1051/0004-6361/201526906Context. The system of four planets discovered around the intermediate-mass star HR8799 offers a unique opportunity to test planet formation theories at large orbital radii and to probe the physics and chemistry at play in the atmospheres of self-luminous young (∼30 Myr) planets. We recently obtained new photometry of the four planets and low-resolution (R∼30) spectra of HR8799 d and e with the SPHERE instrument (paper III). Aims. In this paper (paper IV), we aim to use these spectra and available photometry to determine how they compare to known objects, what the planet physical properties are, and how their atmospheres work. Methods. We compare the available spectra, photometry, and spectral-energy distribution (SED) of the planets to field dwarfs and young companions. In addition, we use the extinction from corundum, silicate (enstatite and forsterite), or iron grains likely to form in the atmosphere of the planets to try to better understand empirically the peculiarity of their spectrophotometric properties. To conclude, we use three sets of atmospheric models (BT-SETTL14, Cloud-AE60, Exo-REM) to determine which ingredients are critically needed in the models to represent the SED of the objects, and to constrain their atmospheric parameters (T eff , log g, M/H). Results. We find that HR8799d and e properties are well reproduced by those of L6-L8 dusty dwarfs discovered in the field, among which some are candidate members of young nearby associations. No known object reproduces well the properties of planets b and c. Nevertheless, we find that the spectra and WISE photometry of peculiar and/or young early-T dwarfs reddened by submicron grains made of corundum, iron, enstatite, or forsterite successfully reproduce the SED of these planets. Our analysis confirms that only the Exo-REM models with thick clouds fit (within 2σ) the whole set of spectrophotometric datapoints available for HR8799 d and e for T eff = 1200 K, log g in the range 3.0-4.5, and M/H=+0.5. The models still fail to reproduce the SED of HR8799c and b. The determination of the metallicity, log g, and cloud thickness are degenerate. Conclusions. Our empirical analysis and atmospheric modelling show that an enhanced content in dust and decreased CIA of H2 is certainly responsible for the deviation of the properties of the planet with respect to field dwarfs. The analysis suggests in addition that HR8799c and b have later spectral types than the two other planets, and therefore could both have lower masses.Peer reviewe

Generic peer-to-peer support for a personal service platform

Building on previous work of the OASIS group at SICS, this paper presents a generic peer-to-peer system for the sView personal service platform. The sView platform provides each user with a personal service briefcase from which services may be reached using a variety of devices and interfaces. With the peer-to-peer system, called Briefcase Connectivity, we leverage the community of all sView users, the ultimate purpose of which is to simplify the propagation of cooperating services, to enable users to become individual service providers, and to bring to the users a greater number of specialized services. We suggest that sView with Briefcase Connectivity and todayís electronic services demonstrate a viable model to make a step toward tomorrowís ubiquitous computing