Di-μ2-bromido-bis­[bromido(η6-1,2,4,5-tetra­methyl­benzene)ruthenium(II)]

The asymmetric unit of the title compound, [Ru2Br4(C10H14)2], contains one half of the centrosymmetric mol­ecule. Each Ru center is coordinated by tetra­methyl­benzene ring in a η6-coordination mode, and one terminal and two bridging bromine atoms. The aromatic rings and the Ru2Br2 four-membered ring form a dihedral angle of 55.99 (8)°. In the crystal structure, weak inter­molecular C—H⋯Br inter­actions link mol­ecules into chains propagated in [001]

Di-μ2-chlorido-bis­[chlorido(η6-hexa­methyl­benzene)ruthenium(II)]

Dimeric mol­ecules of the title compound, [Ru2Cl4(C12H18)2], are located on a crystallographic centre of inversion with one mol­ecule in the asymmetric unit. The hexa­methyl­benzene rings are in an η6-coordination to the ruthenium centres, which are bridged by two chloride ligands. In addition, the ruthenium centres are bonded to another chloride ligand. The aromatic rings and the Ru2Cl2 four-membered ring enclose a dihedral angle of 55.85 (6)°

Charge and spin excitations of insulating lamellar copper oxides

A consistent description of low-energy charge and spin responses of the insulating Sr_2CuO_2Cl_2 lamellar system is found in the framework of a one-band Hubbard model which besides $U$ includes hoppings up to 3^{rd} nearest-neighbors. By combining mean-field calculations, exact diagonalization (ED) results, and Quantum Monte Carlo simulations (QMC), we analyze both charge and spin degrees of freedom responses as observed by optical conductivity, ARPES, Raman and inelastic neutron scattering experiments. Within this effective model, long-range hopping processes flatten the quasiparticle band around $(0,\pi)$. We calculate also the non-resonant A_{1g} and B_{1g} Raman profiles and show that the latter is composed by two main features, which are attributed to 2- and 4-magnon scattering.Comment: 6 pages, 3 figures, To be published in PRB (july

On the maximal superalgebras of supersymmetric backgrounds

In this note we give a precise definition of the notion of a maximal superalgebra of certain types of supersymmetric supergravity backgrounds, including the Freund-Rubin backgrounds, and propose a geometric construction extending the well-known construction of its Killing superalgebra. We determine the structure of maximal Lie superalgebras and show that there is a finite number of isomorphism classes, all related via contractions from an orthosymplectic Lie superalgebra. We use the structure theory to show that maximally supersymmetric waves do not possess such a maximal superalgebra, but that the maximally supersymmetric Freund-Rubin backgrounds do. We perform the explicit geometric construction of the maximal superalgebra of AdS_4 x S^7 and find that is isomorphic to osp(1|32). We propose an algebraic construction of the maximal superalgebra of any background asymptotic to AdS_4 x S^7 and we test this proposal by computing the maximal superalgebra of the M2-brane in its two maximally supersymmetric limits, finding agreement.Comment: 17 page

An in vivo culture system for human embryos using an encapsulation technology: a pilot study

BACKGROUND Animal studies have demonstrated better embryo development in vivo than in vitro. This pilot study tested the feasibility of using a novel in utero culture system (IUCS) to obtain normal human fertilization and embryo development. METHODS The IUCS device comprised a perforated silicone hollow tube. The study included 13 patients (<36 years) undergoing a first intracytoplasmic sperm injection (ICSI) treatment and 167 metaphase II oocytes in three groups. In Group 1, 1-2 h after ICSI, sibling oocytes were assigned to IUCS or conventional in vitro culture. The device was retrieved on Day 1, and all zygotes were cultured in vitro till Day 5. In Group 2, fertilized oocytes were assigned on Day 1, embryos retrieved on Day 3 and all embryos cultured till Day 5. In Group 3, after Day 0 assignment, embryos were retrieved on Day 3 for blastomere biopsy and fluorescence in situ hybridization (FISH) and cultured until Day 5. The highest quality blastocysts were transferred on Day 5. RESULTS Fertilization and embryo development were comparable in the in vitro and IUCS arms, with a tendency towards better embryo quality in the IUCS. FISH analysis in Group 3 revealed more normal embryos using the IUCS (P = 0.049). Three clinical pregnancies and live births were obtained: two from the IUCS arm and one from the in vitro arm. CONCLUSIONS Our pilot study shows that this new IUCS appears to be feasible and safe, supporting normal fertilization, embryo development and normal chromosomal segregation. Furthermore, live births are possible after the transient presence of a silicone device in the uterus.Clinicaltrials.gov: NCT0048010

Understanding the ellagitannin extraction process from oak wood

[EN] The extractability of the main oak ellagitannins has been studied in five model solutions containing different types of oak chips (two sizes and different toasting degrees for each size). A new extraction kinetic model has been proposed from the quantitative experimental results obtained by means of HPLCeESI-MS/MS-multiple reaction monitoring method. The model considers an initial extraction (i.e., washing step) followed by a diffusion step, which involves two different processes that follow first-order kinetics at different rates. Differences in the extractability of the ellagitannins in the different model solutions have been observed and explained on the basis of the kinetic model here proposed

A Shape‐Adaptable Organometallic Supramolecular Coordination Cage for the Encapsulation of Fullerenes

The development of three‐dimensional supramolecular coordination complexes (SCCs), with cavities suitable for guest binding, is of great interest because these materials are useful in a large number of applications. Herein, a nickel‐conjoined organometallic molecular prism is described, which has been fully characterized. The X‐ray diffraction structure of the molecule reveals that the cage possesses an internal cavity with a volume of 1028 Å3, thus suitable for the encapsulation of large 3D‐molecules, such as fullerenes. This cage shows highly selective complexation of C70 over C60, thus being potentially useful for fullerene separation and purification. The combined experimental and computational studies suggest that the complexation process is largely entropically‐driven, and DFT calculations suggest that the cage is flexible and can adapt the size and the shape of the cavity to maximize the face‐to‐face interaction with the fullerenes

Did wine consumption change during the Covid-19 lockdown in France, Italy, Spain, and Portugal?

This article documents how the COVID-19 crisis has affected the drinking behavior of Latin European wine consumers. Using a large online survey conducted during the first lockdown inFrance, Italy, Portugal, and Spain (n= 7,324 individuals), we reconstruct the purchasing and consumption patterns of the respondents. The number of people who maintained their wine consumption frequency is significantly higher than those who increased or decreased their consumption. Wine consumption frequency held up better than other types of alcohol (beer andspirits). We analyze heterogeneities among countries and individuals by employing the Marascuilo procedure and an ordered logit model. The latter identifies the impact of demographic, commercial, and psychosocial factors on wine consumption frequency. The results shed light on changes in wine consumer behavior during the first lockdown and consider possible post-lockdown trends that could be useful to industry players

Kepler observations of variability in B-type stars

The analysis of the light curves of 48 B-type stars observed by Kepler is presented. Among these are 15 pulsating stars, all of which show low frequencies characteristic of SPB stars. Seven of these stars also show a few weak, isolated high frequencies and they could be considered as SPB/beta Cep hybrids. In all cases the frequency spectra are quite different from what is seen from ground-based observations. We suggest that this is because most of the low frequencies are modes of high degree which are predicted to be unstable in models of mid-B stars. We find that there are non-pulsating stars within the beta Cep and SPB instability strips. Apart from the pulsating stars, we can identify stars with frequency groupings similar to what is seen in Be stars but which are not Be stars. The origin of the groupings is not clear, but may be related to rotation. We find periodic variations in other stars which we attribute to proximity effects in binary systems or possibly rotational modulation. We find no evidence for pulsating stars between the cool edge of the SPB and the hot edge of the delta Sct instability strips. None of the stars show the broad features which can be attributed to stochastically-excited modes as recently proposed. Among our sample of B stars are two chemically peculiar stars, one of which is a HgMn star showing rotational modulation in the light curve.Comment: 19 pages, 11 figures, 4 table

Multiple sclerosis management during the COVID-19 pandemic

Altres ajuts: The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors. The development of standardized data collection as part of routine clinical care through Multiple Sclerosis Partners Advancing Technology and Health Solutions (MS PATHS) was developed and implemented at CC, JH, and CEMCAT in partnership with Biogen. Biogen did not have involvement in study design, data analysis or interpretation, or manuscript preparation.People with multiple sclerosis (MS) may be at higher risk for complications from the 2019 coronavirus (COVID-19) pandemic due to use of immunomodulatory disease modifying therapies (DMTs) and greater need for medical services. To evaluate risk factors for COVID-19 susceptibility and describe the pandemic's impact on healthcare delivery. Surveys sent to MS patients at Cleveland Clinic, Johns Hopkins, and Vall d'Hebron-Centre d'Esclerosi Múltiple de Catalunya in April and May 2020 collected information about comorbidities, DMTs, exposures, COVID-19 testing/outcomes, health behaviors, and disruptions to MS care. There were 3028/10,816 responders. Suspected or confirmed COVID-19 cases were more likely to have a known COVID-19 contact (odds ratio (OR): 4.38; 95% confidence interval (CI): 1.04, 18.54). In multivariable-adjusted models, people who were younger, had to work on site, had a lower education level, and resided in socioeconomically disadvantaged areas were less likely to follow social distancing guidelines. 4.4% reported changes to therapy plans, primarily delays in infusions, and 15.5% a disruption to rehabilitative services. Younger people with lower socioeconomic status required to work on site may be at higher exposure risk and are potential targets for educational intervention and work restrictions to limit exposure. Providers should be mindful of potential infusion delays and MS care disruption