2,575 research outputs found
Nuclear matter symmetry energy and the neutron skin thickness of heavy nuclei
Correlations between the thickness of the neutron skin in finite nuclei and
the nuclear matter symmetry energy are studied in the Skyrme Hartree-Fock
model. From the most recent analysis of the isospin diffusion data in heavy-ion
collisions based on an isospin- and momentum-dependent transport model with
in-medium nucleon-nucleon cross sections, a value of MeV for the
slope of the nuclear symmetry energy at saturation density is extracted, and
this imposes stringent constraints on both the parameters in the Skyrme
effective interactions and the neutron skin thickness of heavy nuclei.
Predicted thickness of the neutron skin is fm for Pb,
fm for Sn, and fm for Sn.Comment: 6 pages, 4 figures, 1 table, revised version, to appear in PR
Effect of symmetry energy on two-nucleon correlation functions in heavy-ion collisions induced by neutron-rich nuclei
Using an isospin-dependent transport model, we study the effects of nuclear
symmetry energy on two-nucleon correlation functions in heavy ion collisions
induced by neutron-rich nuclei. We find that the density dependence of the
nuclear symmetry energy affects significantly the nucleon emission times in
these collisions, leading to larger values of two-nucleon correlation functions
for a symmetry energy that has a stronger density dependence. Two-nucleon
correlation functions are thus useful tools for extracting information about
the nuclear symmetry energy from heavy ion collisions.Comment: Revised version, to appear in Phys. Rev. Let
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A 25-hydroxycholecalciferol–fortified dairy drink is more effective at raising a marker of postprandial vitamin D status than cholecalciferol in men with suboptimal vitamin D status
Background: One strategy for improving population vitamin D status is consumption of fortified foods. However, the
effects of dairy products fortified with different vitamin D isoforms on postprandial vitamin D status and metabolic
outcomes have not been addressed.
Objective: We investigated whether consumption of dairy drinks fortified with either 25-hydroxycholecalciferol [25(OH)D3] or
cholecalciferol (vitamin D3) had differential effects on 24-h circulating plasma 25(OH)D3 concentration (a marker of vitamin
D status) and cardiometabolic risk markers.
Methods: A randomized, controlled, 3-way crossover, double-blind, postprandial study was conducted in 17 men with
suboptimal vitamin D status [mean 6 SEM age: 49 6 3 y; body mass index (in kg/m2): 26.4 6 0.6; and plasma 25(OH)D3
concentration: 31.7 6 3.4 nmol/L]. They were randomly assigned to consume 3 different test meals (4.54 MJ, 51 g fat, 125 g
carbohydrate, and 23 g protein),which contained either a nonfortified dairy drink (control), 20 mg 25(OH)D3-fortified (+HyD3) dairy
drink, or 20 mg vitamin D3–fortified (+D3) dairy drink with toasted bread and jam on different occasions, separated by a 2-wk
washout. Plasma 25(OH)D3 concentrations and cardiometabolic risk markers, including vascular stiffness, serum lipids, and
inflammatory markers, were measured frequently within 8 h postprandially and 24 h after the dairy drink was consumed.
Results: Plasma 25(OH)D3 concentrations (the primary outcome) were significantly higher after the +HyD3 dairy drink was
consumed compared with +D3 and control (P = 0.019), which was reflected in the 1.5-fold and 1.8-fold greater incremental
area under the curve for the 0–8 h response, respectively. The change in plasma 25(OH)D3 concentrations from baseline to
24 h for the +HyD3 dairy drink was also 0.9-fold higher than the +D3 dairy drink and 4.4-fold higher than the control
(P < 0.0001), which were not significantly different from each other.
Conclusion: The dairy drink fortified with 25(OH)D3 was more effective at raising plasma 25(OH)D3 concentrations
postprandially than was the dairy drink fortified with vitamin D3 in men with suboptimal vitamin D status
Serum leptin is associated with cardiometabolic risk and predicts metabolic syndrome in Taiwanese adults
<p>Abstract</p> <p>Background</p> <p>Leptin is associated with cardiovascular disease (CVD); however, few studies have assessed its relationship with metabolic syndrome, especially in an Asian population. Therefore, the aim of the present study was to assess leptin levels and evaluate its association with CVD and metabolic syndrome.</p> <p>Methods</p> <p>In 2009, 957 subjects, who underwent a routine physical examination and choose leptin examination, were selected to participate. Participants (269 females and 688 males) were stratified according to leptin level quartiles. Metabolic syndrome was defined by NCEP ATP III using waist circumference cutoffs modified for Asian populations, and CVD risk was determined using the Framingham Heart Study profile.</p> <p>Results</p> <p>Leptin levels were correlated with CVD risk in men and women. With the exception of fasting plasma glucose, increased leptin levels were observed as factors associated with metabolic syndrome increased in both males and females. After adjusting for age, an association between leptin levels and metabolic syndrome was observed. After adjusting for age alone or with tobacco use, subjects in the highest leptin quartile had a higher risk of having metabolic syndrome than those in the lowest quartile (OR = 6.14 and 2.94 for men and women, respectively). After further adjustment for BMI, metabolic syndrome risk remained significantly increased with increasing leptin quartiles in men. Finally, increased leptin levels were a predictor of metabolic syndrome in men and women.</p> <p>Conclusions</p> <p>Serum leptin levels are correlated with CVD risk and metabolic syndrome. Analysis of leptin as part of routine physical examinations may prove beneficial for early diagnosis of metabolic syndrome.</p
Design, synthesis, and protein methyltransferase activity of a unique set of constrained amine containing compounds
Epigenetic alterations relate to various human diseases, and developing inhibitors of Kme regulatory proteins is considered to be a new frontier for drug discovery. We were inspired by the known multicyclic ligands, UNC669 and UNC926, which are the first reported small molecule ligands for a methyl-lysine binding domain. We hypothesized that reducing the conformational flexibility of the key amine moiety of UNC669 would result in a unique set of ligands. Twenty-five novel compounds containing a fused bi- or tricyclic amine or a spirocyclic amine were designed and synthesized. To gauge the potential of these amine-containing compounds to interact with Kme regulatory proteins, the compounds were screened against a panel of 24 protein methyltransferases. Compound 13 was discovered as a novel scaffold that interacts with SETD8 and could serve as a starting point for the future development of PKMT inhibitors
The mechanical relaxation study of polycrystalline MgCNi3
The mechanical relaxation spectra of a superconducting and a
non-superconducting MgCNi3 samples were measured from liquid nitrogen
temperature to room temperature at frequency of kilohertz. There are two
internal friction peaks (at 300 K labeled as P1 and 125 K as P2) for the
superconducting sample. For the non-superconducting one, the position of P1
shifts to 250 K, while P2 is almost completely depressed. It is found that the
peak position of P2 shifts towards higher temperature under higher measuring
frequency. The calculated activation energy is 0.13eV. We propose an
explanation relating P2 to the carbon atom jumping among the off-center
positions. And further we expect that the behaviors of carbon atoms maybe
correspond to the normal state crossovers around 150 K and 50 K observed by
many other experiments.Comment: 4 figure
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Publisher Correction: Copper adparticle enabled selective electrosynthesis of n-propanol.
An amendment to this paper has been published and can be accessed via a link at the top of the paper
Combining machine learning and high-throughput experimentation to discover photocatalytically active organic molecules
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