Constraining the nuclear symmetry energy and properties of neutron star from GW170817 by Bayesian analysis

Based on the distribution of tidal deformabilities and component masses of binary neutron star merger GW170817, the parametric equation of states (EOS) are employed to probe the nuclear symmetry energy and the properties of neutron star. To obtain a proper distribution of the parameters of the EOS that is consistent with the observation, Bayesian analysis is used and the constraints of causality and maximum mass are considered. From this analysis, it is found that the symmetry energy at twice the saturation density of nuclear matter can be constrained within $E_{sym}(2{\rho_{0}})$ = $34.5^{+20.5}_{-2.3}$ MeV at 90\% credible level. Moreover, the constraints on the radii and dimensionless tidal deformabilities of canonical neutron stars are also demonstrated through this analysis, and the corresponding constraints are 10.80 km $< R_{1.4} <$ 13.20 km and $133 < \Lambda_{1.4} < 686$ at 90\% credible level, with the most probable value of $\bar{R}_{1.4}$ = 12.60 km and $\bar{\Lambda}_{1.4}$ = 500, respectively. With respect to the prior, our result (posterior result) prefers a softer EOS, corresponding to a lower expected value of symmetry energy, a smaller radius and a smaller tidal deformability.Comment: 15 pages, 15 figure

GPVI and GPIbα Mediate Staphylococcal Superantigen-Like Protein 5 (SSL5) Induced Platelet Activation and Direct toward Glycans as Potential Inhibitors

Background Staphylococcus aureus (S. aureus) is a common pathogen capable of causing life-threatening infections. Staphylococcal superantigen-like protein 5 (SSL5) has recently been shown to bind to platelet glycoproteins and induce platelet activation. This study investigates further the interaction between SSL5 and platelet glycoproteins. Moreover, using a glycan discovery approach, we aim to identify potential glycans to therapeutically target this interaction and prevent SSL5-induced effects. Methodology/Principal Findings In addition to platelet activation experiments, flow cytometry, immunoprecipitation, surface plasmon resonance and a glycan binding array, were used to identify specific SSL5 binding regions and mediators. We independently confirm SSL5 to interact with platelets via GPIbα and identify the sulphated-tyrosine residues as an important region for SSL5 binding. We also identify the novel direct interaction between SSL5 and the platelet collagen receptor GPVI. Together, these receptors offer one mechanistic explanation for the unique functional influences SSL5 exerts on platelets. A role for specific families of platelet glycans in mediating SSL5-platelet interactions was also discovered and used to identify and demonstrate effectiveness of potential glycan based inhibitors in vitro. Conclusions/Significance These findings further elucidate the functional interactions between SSL5 and platelets, including the novel finding of a role for the GPVI receptor. We demonstrate efficacy of possible glycan-based approaches to inhibit the SSL5-induced platelet activation. Our data warrant further work to prove SSL5-platelet effects in viv

A first-principles study of CO oxidation by surface oxygen on Pt-incorporated perovskite catalyst (CaPtxTi1-xO3)

In the present work, we investigated the structural and catalytic properties of a prototype system Pt-doped CaTiO3 by means of first principles calculations. We paid particular attention to the aggregation and penetration of Pt on different surfaces of CaTiO3, and subsequent CO oxidation by surface oxygen atoms on Pt-doped CaTiO3. Our calculations indicate that CO oxidation can potentially take place when Pt is doped on the first layer of CaTiO3(001). The activation barriers are calculated to be 0.20-0.45 eV. The possibly induced O vacancy on the surface will produce a magnetic behavior by breaking the spin density symmetry due to one Pt-O bond cleavage. Our study is expected to provide an insight into the catalytic behavior of Pt ions in Pt-doped perovskite toward the oxidation of exhaust gas

Preliminary validation of a Chinese version of the comprehensive assessment of acceptance and commitment therapy processes

Acceptance and Commitment Therapy (ACT) improves mental health by augmenting psychological flexibility. Studies showed that psychological flexibility affects mental health; however, although studies have examined individual aspects of psychological flexibility, few have comprehensively examined an entire psychological flexibility model, especially in China. The Comprehensive Assessment of Acceptance and Commitment Therapy Processes (CompACT) is a comprehensive evaluation method that reflects psychological flexibility. The objectives of this study were to develop a Chinese version of CompACT that fits with Chinese culture and examine its reliability and validity. We studied 4999 non-clinical Chinese civil servants and explored the characteristics of the Chinese version of CompACT. Exploratory factor analysis was used to measure Openness to Experience, Behavioral Awareness, and Valued Action that explained 54.3% of the total variance. Confirmatory factor analysis provided support for the three-factor model. The Cronbach&#39;s alpha-coefficient of the scale was 0.87, suggesting that the Chinese version of the CompACT is reliable. The Chinese CompACT total score represents the overall level of psychological flexibility; it is significantly negatively correlated with negative emotions and positively associated with well-being. Our findings suggest that the Chinese version of the CompACT accurately assesses psychological flexibility in Chinese adults.</p

First principles study of enhanced CO2 adsorption on MOF-253 by salt-insertion

We investigated the basic electron variation in salt-chelated MOF-253 and revealed increased CO2 adsorption by chelating PdCl2 and Cu(BF4)(2) through the DFT-D2 method. The two N atoms preferentially orient to opposite side of the 2,2'-bipyridine (bpy) in bare MOF-253 to yield a CO2 adsorption energy of -0.15 eV, which mainly contributes to the experimentally determined isotopic heat energy of -0.24 eV. Following salt insertion, the two pyridine rings rotate to the same side to hold the salt that binds on NN atoms. While PdCl2 insertion does not significantly enhance CO2 adsorption, dipole polarization creates multiple adsorption sites by adding a PdACl bond and co-linker site, thereby increasing the adsorption capacity of the resultant material. Cu(BF4)(2) chelation significantly increases the CO2 adsorption energy to -0.49 eV, which is ascribed to the large positive charge of the Cu ion inducing significant electrostatic interactions with the O atom of CO2. Our calculation results demonstrate the effect of inherent electron distribution during salt insertion on CO2 adsorption and clearly explain the observed 7 kJ/mol enhancement in CO2 absorption upon loading of Cu(BF4)(2) on MOF-253. This study provides new insights into the selection of an ideal salt for chelation with the open bpy linker to improve gas uptake and illustrates the potential application of catalysis by MOF-253 to gas conversion. (C) 2015 Elsevier B.V. All rights reserved

East Asian summer monsoon precipitation variability since the last deglaciation

The lack of a precisely-dated, unequivocal climate proxy from northern China, where precipitation variability is traditionally considered as an East Asian summer monsoon (EASM) indicator, impedes our understanding of the behaviour and dynamics of the EASM. Here we present a well-dated, pollen-based, ~20-yr-resolution quantitative precipitation reconstruction (derived using a transfer function) from an alpine lake in North China, which provides for the first time a direct record of EASM evolution since 14.7 ka (ka = thousands of years before present, where the “present” is defined as the year AD 1950). Our record reveals a gradually intensifying monsoon from 14.7–7.0 ka, a maximum monsoon (30% higher precipitation than present) from ~7.8–5.3 ka, and a rapid decline since ~3.3 ka. These insolation-driven EASM trends were punctuated by two millennial-scale weakening events which occurred synchronously to the cold Younger Dryas and at ~9.5–8.5 ka, and by two centennial-scale intervals of enhanced (weakened) monsoon during the Medieval Warm Period (Little Ice Age). Our precipitation reconstruction, consistent with temperature changes but quite different from the prevailing view of EASM evolution, points to strong internal feedback processes driving the EASM, and may aid our understanding of future monsoon behaviour under ongoing anthropogenic climate change

Initial investigation of B4C-TiB2 composites as neutron absorption material for nuclear reactors

In this study, a specifically designed B4C-TiB2 composite with the typical microstructural feature of a TiB2 network (cages) that encapsulates a B4C matrix was fabricated by the molten-salt and spark plasma sintering (SPS) method. The finite-element (FE) calculation results show that the connected TiB2 cages constitute a thermally conductive network, which effectively improves the overall thermal conductivity of the composite; these results agree well with the experimental results. Moreover, the Vickers indentation results reveal that the TiB2 network (cages) can effectively impinge/block the propagation of cracks, which increases the composite toughness. The composite was subjected to helium (He) ion irradiation to simulate the situation in which the B4C-TiB2 composites serve as neutron absorption material, and for which case a high quantity of He atoms is produced by the B-10(n, alpha)Li-7 nuclear reaction. According to the transmission electron microscopy (TEM) results, the interfaces between TiB2 and B4C act as effective sinks for He atoms, and are preferential nucleation sites for He bubbles. The theoretical and experimental results show that when the B4C-TiB2 composites serve as neutron absorption pellets in nuclear reactors, they exhibit a better resistance to their disintegration than pure B4C pellets. Consequently, the performance of the control rods of nuclear reactors can be improved. (C) 2020 Elsevier B.V. All rights reserved