9 research outputs found
In Quest of Strong BeâNg Bonds among the Neutral NgâBe Complexes
The
global minimum geometries of BeCN<sub>2</sub> and BeNBO are linear
BeNâCN and BeNâBO, respectively. The Be center of BeCN<sub>2</sub> binds He with the highest BeâHe dissociation energy
among the studied neutral HeâBe complexes. In addition, BeCN<sub>2</sub> can be further tuned as a better noble gas trapper by attaching
it with any electron-withdrawing group. Taking BeO, BeS, BeNH, BeNBO,
and BeCN<sub>2</sub> systems, the study at the CCSDÂ(T)/def2-TZVP level
of theory also shows that both BeCN<sub>2</sub> and BeNBO systems
have higher noble gas binding ability than those related reported
systems. Î<i>G</i> values for the formation of NgBeCN<sub>2</sub>/NgBeNBO (Ng = ArâRn) 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 CâC 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, BornâOppenheimer 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