4,404 research outputs found
Simplified TeV leptophilic dark matter in light of DAMPE data
Using a simplified framework, we attempt to explain the recent DAMPE cosmic
flux excess by leptophilic Dirac fermion dark matter (LDM). The
scalar () and vector () mediator fields connecting LDM and
Standard Model particles are discussed. Under constraints of DM relic density,
gamma-rays, cosmic-rays and Cosmic Microwave Background (CMB), we find that the
couplings , , and can
produce the right bump in flux for a DM mass around 1.5 TeV with a
natural thermal annihilation cross-section today. Among them, coupling is tightly constrained by
PandaX-II data (although LDM-nucleus scattering appears at one-loop level) and
the surviving samples appear in the resonant region, . We also study the related collider signatures, such as dilepton
production , and muon anomaly. Finally,
we present a possible realization for such leptophilic dark matter.Comment: discussions added, version accepted by JHE
Stabilnost i antioksidacijska aktivnost antocijanina iz borovnica
Anthocyanins from highbush blueberry (Vaccinium corymbosum L.) have tremendous potential as natural colorants and functional food with pharmaceutical purposes in food applications. To exploit the potential for food applications, the stability and antioxidant activity of anthocyanins present in blueberries have been studied. The results indicate that anthocyanins from blueberry were stable against the low pH (≤5.0), NaCl (0.125–0.500 mol/L), sucrose (0.584–2.336 mol/L) and preservative (sodium benzoate, 0.035–0.140 mol/L), but were sensitive to alkaline conditions (≥7.0), high temperature (≥80 °C), light (natural light), oxidizing agent (H2O2, 0.5–2.0 %) and reducing agent (Na2SO3, 0.005–0.040 mol/L). At concentrations of 25 and 50 mg/mL, anthocyanins from blueberry could protect ECV-304 cells against oxidative damage induced by H2O2. These results suggest that anthocyanins from blueberry can be regarded as a potential colorant for some acidic (pH≤5.0) food products and could be used as health food to prevent diseases arising from oxidative processes.Antocijanini iz američkih borovnica (Vaccinium corymbosum L.) koriste se u prehrambenoj industriji kao prirodna bojila i za proizvodnju funkcionalne hrane. Stoga je u radu ispitana stabilnost i antioksidacijska aktivnost antocijanina izoliranih iz borovnica. Rezultati pokazuju da su antocijanini bili stabilni pri niskoj pH-vrijednosti (pH≤5) te malim koncentracijama soli (0,125–0,500 mol/L), saharoze (0,584–2,336 mol/L) i konzervansa natrijeva benzoata (0,035–0,140 mol/L), ali osjetljivi u lužnatoj sredini (pH≥7), pri visokoj temperaturi (≥80 °C), na prirodnom izvoru svjetlosti i u prisutnosti oksidansa (H2O2, 0,5–2 %) i reducensa (Na2SO3, 0,005–0,04 mol/L). Antocijanini iz borovnica u koncentracijama od 25 i 50 μg/mL štite ECV-304 stanice od stresa uzrokovanog dodatkom vodikova peroksida. Rezultati pokazuju da se antocijanini iz borovnica mogu upotrijebiti kao bojilo u proizvodnji hrane male pH-vrijednosti (pH≤5) te u proizvodnji zdrave hrane koja sprječava razvoj bolesti uzrokovanih oksidacijskim stresom
Attention Optimization for Abstractive Document Summarization
Attention plays a key role in the improvement of sequence-to-sequence-based
document summarization models. To obtain a powerful attention helping with
reproducing the most salient information and avoiding repetitions, we augment
the vanilla attention model from both local and global aspects. We propose an
attention refinement unit paired with local variance loss to impose supervision
on the attention model at each decoding step, and a global variance loss to
optimize the attention distributions of all decoding steps from the global
perspective. The performances on the CNN/Daily Mail dataset verify the
effectiveness of our methods
Nonlocal coherence harvesting from quantum vacuum
It is well known that nonlocal coherence reflects nonclassical correlations
better than quantum entan-glement. Here, we analyze nonlocal coherence
harvesting from the quantum vacuum to particle detectors adiabatically
interacting with a quantum scalar field in Minkowski spacetime. We find that
the harvesting-achievable separation range of nonlocal coherence is larger than
that of quantum entanglement. As the energy gap grows sufficiently large, the
detectors harvest less quantum coherence, while the detectors could extract
more quantum entanglement from the vacuum state. Compared with the linear
configuration and the scalene configuration, the equilateral triangle
configuration is the best model to harvest tripartite coherence. Finally, we
find a monogamous relationship, which means that tripartite l1-norm of
coherence is essentially bipartite types.Comment: 18 pages, 5 figure
Synthetic rabbit-human antibody conjugate as a control in immunoassays for immunoglobulin M specific to hepatitis E virus
<p>Abstract</p> <p>Background</p> <p>In assays for anti-hepatitis E virus (HEV) immunoglobulin M (IgM), large volumes of the patient's sera cannot be easily obtained for use as a positive control. In this study, we investigated an alternative chemical method in which rabbit anti-HEV IgG was conjugated with human IgM and was used as a positive control in the anti-HEV IgM assay. Rabbit anti-HEV IgG was isolated from immune sera by chromatography on protein A-Sepharose and was conjugated with human IgM by using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC) as a crosslinker.</p> <p>Results</p> <p>The specific anti-HEV IgG antibody titer was 100,000 times that of the negative control, i.e., prebleed rabbit serum. The results of anti-HEV IgM enzyme-linked immunosobent assay showed that the antibody conjugate was similar to anti-HEV IgM antibodies produced in humans. The results of a stability experiment showed that the antibody conjugate was stable for use in external quality assessment or internal quality control trials.</p> <p>Conclusions</p> <p>We concluded that the chemically conjugated rabbit-human antibody could be used instead of the traditional serum control as a positive control in the anti-HEV IgM assay.</p
Direct detection of cosmic ray-boosted puffy dark matter
For the light relativistic dark matter (DM) boosted by high energy cosmic
ray, its scattering cross section with the nucleon is sensitively dependent on
the momentum-transfer and such an dependence is caused by the mediator in the
scattering. For puffy DM particle with a size, the momentum-transfer dependence
can also arise from the DM radius effect. All these momentum-transfer
dependences should be considered. In this note we study the direct detection
limits on the cosmic ray-boosted puffy DM for a simplified model with a light
mediator. For comparison, we first re-derive the direct detection limits on the
cosmic ray-boosted point-like DM. We display the limits on various planes of
parameters and find that the limits for the cosmic ray-boosted puffy DM are
stronger than for the point-like DM.Comment: 14 pages, 7 figure
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