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Changes in consumption of added sugars from age 13 to 30 years: a systematic review and meta-analysis of longitudinal studies
Added sugar intake during adolescence has been associated with weight gain and cardiometabolic risk factors. Moreover, dietary habits may persist into adulthood, increasing chronic disease risk in later life. This systematic review investigated changes in intake of added sugars between the ages of 13 and 30 years.
Literature databases were searched for longitudinal studies of diet during adolescence or early adulthood. Retrieved articles were screened for studies including multiple measures of intake of sugars or sugary foods from cohort participants between the ages of 13 and 30. Data were analysed using random-effects meta-analysis, by the three main nutrient and food group categories identified (PROSPERO: CRD42015030126).
Twenty-four papers reported longitudinal data on intake of added sugar or sucrose ( = 6), sugar-sweetened beverages (SSBs) ( = 20) and/or confectionery ( = 9). Meta-analysis showed a non-significant per year of age decrease in added sugar or sucrose intake (-0.15% total energy intake (95%CI -0.41; 0.12)), a decrease in confectionery consumption (-0.20 servings/week (95%CI -0.41; -0.001)) and a non-significant decrease in SSB consumption (-0.15 servings/week (95%CI -0.32; 0.02)). Taken together, the overall decrease in added sugar intake observed from adolescence to early adulthood may suggest opportunities for intervention to further improve dietary choices within this age range
Quantum information analysis of electronic states at different molecular structures
We have studied transition metal clusters from a quantum information theory
perspective using the density-matrix renormalization group (DMRG) method. We
demonstrate the competition between entanglement and interaction localization.
We also discuss the application of the configuration interaction based
dynamically extended active space procedure which significantly reduces the
effective system size and accelerates the speed of convergence for complicated
molecular electronic structures to a great extent. Our results indicate the
importance of taking entanglement among molecular orbitals into account in
order to devise an optimal orbital ordering and carry out efficient
calculations on transition metal clusters. We propose a recipe to perform DMRG
calculations in a black-box fashion and we point out the connections of our
work to other tensor network state approaches
A cationic and ferromagnetic hexametallic Mn(III) single-molecule magnet based on the salicylamidoxime ligand
Limits on intrinsic magnetism in graphene
We have studied magnetization of graphene nanocrystals obtained by sonic
exfoliation of graphite. No ferromagnetism is detected at any temperature down
to 2 K. Neither do we find strong paramagnetism expected due to the massive
amount of edge defects. Rather, graphene is strongly diamagnetic, similar to
graphite. Our nanocrystals exhibit only a weak paramagnetic contribution
noticeable below 50K. The measurements yield a single species of defects
responsible for the paramagnetism, with approximately one magnetic moment per
typical graphene crystallite.Comment: 2nd version, modified in response to comment
Change in diet in the period from adolescence to early adulthood: a systematic scoping review of longitudinal studies
Late adolescence to early adulthood is a period of lifestyle change and personal development which may influence dietary behaviour. Understanding dietary trajectories across this age range may help in targeting interventions appropriately. This scoping review aimed to assess how longitudinal change in diet is conceptualised and measured between the ages of 13 to 30.We searched Medline, SCOPUS, Embase, PsycInfo (EBSCO), ASSIA, Sportdiscus, and Web of Science Core Collection (January 2016) using search terms combining diet outcomes, longitudinal methods and indicators of adolescent or young adult age. Titles and abstracts were screened and data extracted following published guidelines for scoping reviews. Data were analysed to summarize key data on each study and map availability of longitudinal data on macronutrients and food groups by age of study participants.We identified 98 papers reporting on 40 studies. Longitudinal dietary data were available on intake of energy, key macronutrients and several food groups, but this data had significant gaps and limitations. Most studies provided only two or three waves of data within the age range of interest and few studies reported data collected beyond the early twenties. A range of dietary assessment methods were used, with greater use of less comprehensive dietary assessment methods among studies reporting food group intakes.Despite limited availability of longitudinal data to aid understanding of dietary trajectories across this age range, this scoping review identified areas with scope for further evidence synthesis. We identified a paucity of longitudinal data continuing into the mid and late twenties, variability in (quality of) dietary assessment methods, and a large variety of macronutrients and food groups studied. Advances in dietary assessment methodologies as well as increased use of social media may facilitate new data collection to further understanding of changing diet across this life stage
On the possibility of magneto-structural correlations: detailed studies of di-nickel carboxylate complexes
A series of water-bridged dinickel complexes of the general formula [Ni<sub>2</sub>(μ<sub>2</sub>-OH<sub>2</sub>)(μ2-
O<sub>2</sub>C<sup>t</sup>Bu)<sub>2</sub>(O<sub>2</sub>C<sup>t</sup>Bu)2(L)(L0)] (L = HO<sub>2</sub>C<sup>t</sup>Bu, L0 = HO<sub>2</sub>C<sup>t</sup>Bu (1), pyridine (2),
3-methylpyridine (4); L = L0 = pyridine (3), 3-methylpyridine (5)) has been synthesized
and structurally characterized by X-ray crystallography. The magnetic properties
have been probed by magnetometry and EPR spectroscopy, and detailed measurements
show that the axial zero-field splitting, D, of the nickel(ii) ions is on the same order as
the isotropic exchange interaction, J, between the nickel sites. The isotropic exchange
interaction can be related to the angle between the nickel centers and the bridging
water molecule, while the magnitude of D can be related to the coordination sphere at
the nickel sites
Spin dynamics of molecular nanomagnets fully unraveled by four-dimensional inelastic neutron scattering
Molecular nanomagnets are among the first examples of spin systems of finite
size and have been test-beds for addressing a range of elusive but important
phenomena in quantum dynamics. In fact, for short-enough timescales the spin
wavefunctions evolve coherently according to the an appropriate cluster
spin-Hamiltonian, whose structure can be tailored at the synthetic level to
meet specific requirements. Unfortunately, to this point it has been impossible
to determine the spin dynamics directly. If the molecule is sufficiently
simple, the spin motion can be indirectly assessed by an approximate model
Hamiltonian fitted to experimental measurements of various types. Here we show
that recently-developed instrumentation yields the four-dimensional
inelastic-neutron scattering function S(Q,E) in vast portions of reciprocal
space and enables the spin dynamics to be determined with no need of any model
Hamiltonian. We exploit the Cr8 antiferromagnetic ring as a benchmark to
demonstrate the potential of this new approach. For the first time we extract a
model-free picture of the quantum dynamics of a molecular nanomagnet. This
allows us, for example, to examine how a quantum fluctuation propagates along
the ring and to directly test the degree of validity of the
N\'{e}el-vector-tunneling description of the spin dynamics
Recipes for spin-based quantum computing
Technological growth in the electronics industry has historically been
measured by the number of transistors that can be crammed onto a single
microchip. Unfortunately, all good things must come to an end; spectacular
growth in the number of transistors on a chip requires spectacular reduction of
the transistor size. For electrons in semiconductors, the laws of quantum
mechanics take over at the nanometre scale, and the conventional wisdom for
progress (transistor cramming) must be abandoned. This realization has
stimulated extensive research on ways to exploit the spin (in addition to the
orbital) degree of freedom of the electron, giving birth to the field of
spintronics. Perhaps the most ambitious goal of spintronics is to realize
complete control over the quantum mechanical nature of the relevant spins. This
prospect has motivated a race to design and build a spintronic device capable
of complete control over its quantum mechanical state, and ultimately,
performing computations: a quantum computer.
In this tutorial we summarize past and very recent developments which point
the way to spin-based quantum computing in the solid-state. After introducing a
set of basic requirements for any quantum computer proposal, we offer a brief
summary of some of the many theoretical proposals for solid-state quantum
computers. We then focus on the Loss-DiVincenzo proposal for quantum computing
with the spins of electrons confined to quantum dots. There are many obstacles
to building such a quantum device. We address these, and survey recent
theoretical, and then experimental progress in the field. To conclude the
tutorial, we list some as-yet unrealized experiments, which would be crucial
for the development of a quantum-dot quantum computer.Comment: 45 pages, 12 figures (low-res in preprint, high-res in journal)
tutorial review for Nanotechnology; v2: references added and updated, final
version to appear in journa
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