1,054 research outputs found
Bis(3-methylanilinium) naphthalene-1,5-disulfonate
In the crystal of the title molecular salt, 2C7H10N+·C10H6O6S2
2−, the naphthalene-1,5-disulfonate anion is located on an inversion center and accepts N—H⋯O hydrogen bonds from the 3-methylanilinium cations, forming supramolecular layers parallel to the ac plane
Studying newborn neutron stars by the transient emission after stellar collapses and compact binary mergers
The formation of neutron stars (NSs), both from collapses of massive stars
and mergers of compact objects, can be usually indicated by bright transients
emitted from explosively-ejected material. In particular, if the newborn NSs
can rotate at a millisecond period and have a sufficiently high magnetic field,
then the spin-down of the NSs would provide a remarkable amount of energy to
the emitting material. As a result, super-luminous supernovae could be produced
in the massive stellar collapse cases, while some unusual fast evolving and
luminous optical transients could arise from the cases of NS mergers and
accretion-induced collapses of white dwarfs. In all cases, if the dipolar
magnetic fields of the newborn NSs can be amplified to be as high as
G, a relativistic jet could be launched and then a gamma-ray burst can be
produced as the jet successfully breaks out from the surrounding
nearly-isotropic ejected material.Comment: 10 pages, 9 pictures, to appear in the AIP Proceedings of the
Xiamen-CUSTIPEN Workshop on the EOS of Dense Neutron-Rich Matter in the Era
of Gravitational Wave Astronomy, Jan. 3-7, Xiamen, Chin
A comparison of acidic and enzymatic hydrolysis of rutin
Rutin and its hydrolysis products (isoquercitrin and quercetin) are widely used as important materials in food and pharmaceutical industry. In this study, the effects of various acids and enzymes as catalysts on the hydrolysis reaction of rutin were studied. In comparison with acidic and enzymatic catalysis of rutin, the research results indicated that there was a sharp difference in the selectivity of hydrolysis product between the methods. When 2.5% H3PO4, 1% HCl and 0.5% H2SO4 were used as catalysts, transformation yields of isoquercitin hydrolyzed from rutin were 9.60, 0.69 and 1.25%, but those of quercetin were 11.13, 100 and 2.57%, respectively. When hesperidinase, snailase and cellulase-T2440 were used as catalysts, transformation yields of isoquercitin hydrolyzed from rutin were 43.21, 3.07 and 0.00%, but those of quercetin were 58.10, 96.39 and 30.89%, respectively. In conclusion, the aglycon of rutin was deglycosolated easily under mild acidic hydrolysis conditions at appropriate temperatures, but its secondary glucoside was difficult to be obtained. Contrarily, the prepared isoquercitrin by enzymatic hydrolysis of rutin was preferable to the acidic hydrolysis, especially for hesperidinase.Key words: Rutin, isoquercitrin, quercetin, hydrolysis, acid, enzym
The influence of hadronic rescatterings on the net-baryon number fluctuations
Fluctuations of conserved charges, such as the net-baryon number
fluctuations, are influenced by different dynamical evolution processes. In
this paper, we investigate the influence of hadronic rescatterings on different
orders of cumulants of the net-baryon number distribution. At the start of
hadronic rescatterings, we introduce net-baryon number distributions
reconstructed based on net-baryon cumulants of different orders obtained from
computation in functional renormalization group (FRG), where the distributions
were constructed using the maximum entropy method. This way we introduce the
critical fluctuations of Quantum Chromodynamics (QCD) into the AMPT model.
Firstly, we find that hadronic rescatterings have distinct effects on cumulant
ratios of different orders for the net-baryon number. Secondly, we observe that
the effect of hadronic rescatterings is more significant for critical
fluctuations than dynamical fluctuations, because the two-, three- and
four-particle correlation functions due to critical fluctuations are weakened
more significantly by hadronic rescatterings.Comment: 10 pages, 8 figure
SARS-CoV-2 Causes a Significant Stress Response Mediated by Small RNAs in the Blood of COVID-19 Patients
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has had a serious impact on the world. In this study, small RNAs from the blood of COVID-19 patients with moderate or severe symptoms were extracted for high-throughput sequencing and analysis. Interestingly, the levels of a special group of tRNA-derived small RNAs (tsRNAs) were found to be dramatically upregulated after SARS-CoV-2 infection, particularly in coronavirus disease 2019 (COVID-19) patients with severe symptoms. In particular, the 3′CCA tsRNAs from tRNA-Gly were highly consistent with the inflammation indicator C-reactive protein (CRP). In addition, we found that the majority of significantly changed microRNAs (miRNAs) were associated with endoplasmic reticulum (ER)/unfolded protein response (UPR) sensors, which may lead to the induction of proinflammatory cytokine and immune responses. This study found that SARS-CoV-2 infection caused significant changes in the levels of stress-associated small RNAs in patient blood and their potential functions. Our research revealed that the cells of COVID-19 patients undergo tremendous stress and respond, which can be reflected or regulated by small non-coding RNA (sncRNAs), thus providing potential thought for therapeutic intervention in COVID-19 by modulating small RNA levels or activities
Patterned Electrode Assisted One-Step Fabrication of Biomimetic Morphing Hydrogels with Sophisticated Anisotropic Structures
Anisotropic structures are ubiquitous in nature, affording fascinating morphing behaviors. Biomimetic morphing materials can be developed by spatially controlling the orientations of molecules or nanofillers that produce anisotropic responses and internal stresses under external stimuli. However, it remains a serious challenge to fabricate materials with sophisticated anisotropic architectures. Here, a facile strategy to fabricate morphing hydrogels with elaborately ordered structures of nanosheets, which are oriented under distributed electric field and immobilized by polymerization to form a poly(N‐isopropylacrylamide) matrix, is proposed. Diverse sophisticated anisotropic structures are obtained by engineering the electric field through the patterns and relative locations of the electrodes. Upon heating, the monolithic hydrogels with through‐thickness and/or in‐plane gradients in orientation of the nanosheets deform into various three‐dimensional configurations. After incorporating gold nanoparticles, the hydrogels become photoresponsive and capable of programmable motions, for example, dynamic twisting and flipping under spatiotemporal stimuli. Such a strategy of using patterned electrodes to generate distributed electric field should be applicable to systems of liquid crystals or charged particles/molecules to direct orientation or electrophoresis and form functional structures. The biomimetically architectured hydrogels would be ideal materials to develop artificial muscles, soft actuators/robots, and biomedical devices with versatile applications
- …