In Quest of Strong Be–Ng Bonds among the Neutral Ng–Be Complexes

The global minimum geometries of BeCN₂ and BeNBO are linear BeN–CN and BeN–BO, respectively. The Be center of BeCN₂ binds He with the highest Be–He dissociation energy among the studied neutral He–Be complexes. In addition, BeCN₂ can be further tuned as a better noble gas trapper by attaching it with any electron-withdrawing group. Taking BeO, BeS, BeNH, BeNBO, and BeCN₂ systems, the study at the CCSD­(T)/def2-TZVP level of theory also shows that both BeCN₂ and BeNBO systems have higher noble gas binding ability than those related reported systems. Δ<i>G</i> values for the formation of NgBeCN₂/NgBeNBO (Ng = Ar–Rn) are negative at room temperature (298 K), whereas the same becomes negative at low temperature for Ng = He and Ne. The polarization plus the charge transfer is the dominating term in the interaction energy

Carbo-Cages: A Computational Study

Inspired by their geometrical perfection, intrinsic beauty, and particular properties of polyhedranes, a series of carbo-cages is proposed in silico via density functional theory computations. The insertion of alkynyl units into the C–C bonds of polyhedranes results in a drastic lowering of the structural strain. The induced magnetic field shows a significant delocalization around the three-membered rings. For larger rings, the response is paratropic or close to zero, suggesting a nonaromatic behavior. In the carbo-counterparts, the values of the magnetic response are shifted with respect to their parent compounds, but the aromatic/nonaromatic character remains unaltered. Finally, Born–Oppenheimer molecular dynamics simulations at 900 K do not show any drastic structural changes up to 10 ps. In the particular case of a carbo-prismane, no structural change is perceived until 2400 K. Therefore, although carbo-cages have enthalpies of formation 1 order of magnitude higher than those of their parent compounds, their future preparation and isolation should not be discarded, because the systems are kinetically stable, explaining why the similar systems like carbo-cubane have already been synthesized

Multivariate linear regression analysis of the bacterial groups significantly different between active and sedentary women as dependent variants, and diet composition, fecal water, body composition parameters and physical activity parameters as independent variables.

<p>Multivariate linear regression analysis of the bacterial groups significantly different between active and sedentary women as dependent variants, and diet composition, fecal water, body composition parameters and physical activity parameters as independent variables.</p

Consumption of macronutrients, fiber, ethanol and main food groups.

<p>Consumption of macronutrients, fiber, ethanol and main food groups.</p

Fat and muscle body composition parameters.

<p>Fat and muscle body composition parameters.</p

Changes induced in relative abundance of gut bacteria species by lifestyle in women.

<p>(A) <i>Bifidobacterium longum</i>, <i>(</i>B) <i>Faecalibacterium prausnitzii</i>, (C) <i>Roseburia hominis</i>, (D) <i>Akkermansia muciniphila</i>. Data were log transformed and analyzed by t-test * p<0.05 **p<0.01.</p

Bacterial phyla and families in feces of active and sedentary women.

<p>Bacterial phyla and families in feces of active and sedentary women.</p

Spearman correlation of microbiota genera, body composition and physical activity parameters.

<p>Spearman correlation of microbiota genera, body composition and physical activity parameters.</p

Differences in gut microbiota profile between women with active lifestyle and sedentary women - Fig 1

<p><b>Principal Coordinates Analysis (PcoA) plots of unweighted (A) and weighted (B) Unifrac distance metrics obtained from sequencing the 16s rRNA gene in fecal samples</b>. Axes represent percentage of data explained by each coordinate dimension.</p