706 research outputs found

    Confusion noise from Galactic binaries for Taiji

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    Gravitational waves (GWs) from tens of millions of compact binaries in our Milky Way enter the milli-Hertz band of space-based detection. The majority of them cannot be resolved individually, resulting in a foreground confusion noise for Laser Interferometer Space Antenna (LISA). The concept of Taiji mission is similar to LISA's with slightly better sensitivity, which means that the galactic GW signals will also affect the detection with Taiji. Here we generate the GW signals from 29.8 million galactic binaries for Taiji and subtract the `resolvable' sources. The confusion noise is estimated and fitted in an analytic form with 6-month, 1-year, 2-year and 4-year observation time. We find that the full sensitivity curve is slightly lower for Taiji than for LISA at frequencies of 0.8\leq 0.8 mHz and around 2~mHz. For a 4-year lifetime, more than 29 thousand sources are resolvable with Taiji. Compared to LISA, Taiji can subtract 20%\sim 20 \% more sources and the distribution of them in our Milky Way is consistent with that of the resolvable sources with LISA. At frequencies around 2~mHz or with the chirp masses ranging from 0.2M0.2 M_\odot to 0.4M0.4 M_\odot, more sources become resolvable with Taiji.Comment: 7 pages, 5 figures. Version accepted by PR

    Parameter inference for coalescing massive black hole binaries using deep learning

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    In the 2030s, a new era of gravitational-wave (GW) observations will dawn as multiple space-based GW detectors, such as the Laser Interferometer Space Antenna, Taiji and TianQin, open the millihertz window for GW astronomy. These detectors are poised to detect a multitude of GW signals emitted by different sources. It is a challenging task for GW data analysis to recover the parameters of these sources at a low computational cost. Generally, the matched filtering approach entails exploring an extensive parameter space for all resolvable sources, incurring a substantial cost owing to the generation of GW waveform templates. To alleviate the challenge, we make an attempt to perform parameter inference for coalescing massive black hole binaries (MBHBs) using deep learning. The model trained in this work has the capability to produce 50,000 posterior samples for redshifted total mass, mass ratio, coalescence time and luminosity distance of a MBHB in about twenty seconds. Our model can serve as a potent data pre-processing tool, reducing the volume of parameter space by more than four orders of magnitude for MBHB signals with a signal-to-noise ratio larger than 100. Moreover, the model exhibits robustness when handling input data that contains multiple MBHB signals.Comment: 8 pages, 4 figure

    Gravitational and electromagnetic radiation from binary black holes with electric and magnetic charges: Elliptical orbits on a cone

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    Extending the electromagnetic and gravitational radiations from binary black holes with electric and magnetic charges in circular orbits in Phys. Rev. D {\bf 102}, 103520 (2020), we calculate the total emission rates of energy and angular momentum due to gravitational and electromagnetic radiations from dyonic binary black holes in precessing elliptical orbits. It is shown that the emission rates of energy and angular momentum due to gravitational and electromagnetic radiations have the same dependence on the conic angle for different orbits. Moreover, we obtain the evolutions of orbits and find that a circular orbit remains circular while an elliptic orbit becomes quasi-circular due to electromagnetic and gravitational radiations. Using the evolution of orbits, we derive the waveform models for dyonic binary black hole inspirals and show the amplitudes of the gravitational waves for dyonic binary black hole inspirals differ from those for Schwarzschild binary black hole inspirals, which can be used to test electric and magnetic charges of black holes.Comment: 10 pages, 2 figures, a new section adde

    Effect of route of delivery on heterologous protection against HCV induced by an adenovirus vector carrying HCV structural genes

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    BACKGROUND: An effective vaccine and new therapeutic methods for hepatitis C virus (HCV) are needed, and a potent HCV vaccine must induce robust and sustained cellular-mediated immunity (CMI). Research has indicated that adenoviral and vaccinia vectors may have the ability to elicit strong B and T cell immune responses to target antigens. RESULTS: A recombinant replication-defective adenovirus serotype 5 (rAd5) vector, rAd5-CE1E2, and a recombinant Tian Tan vaccinia vector, rTTV-CE1E2, were constructed to express the HCV CE1E2 gene (1-746 amino acid HCV 1b subtype). Mice were prime-immunised with rAd5-CE1E2 delivered via intramuscular injection (i.m.), intranasal injection (i.n.), or intradermal injection (i.d.) and boosted using a different combination of injection routes. CMI was evaluated via IFN-γ ELISPOT and ICS 2 weeks after immunisation, or 16 weeks after boost for long-term responses. The humoral response was analysed by ELISA. With the exception of priming by i.n. injection, a robust CMI response against multiple HCV antigens (core, E1, E2) was elicited and remained at a high level for a long period (16 weeks post-vaccination) in mice. However, i.n. priming elicited the highest anti-core antibody levels. Priming with i.d. rAd5-CE1E2 and boosting with i.d. rTTV-CE1E2 carried out simultaneously enhanced CMI and the humoral immune response, compared to the homologous rAd5-CE1E2 immune groups. All regimens demonstrated equivalent cross-protective potency in a heterologous surrogate challenge assay based on a recombinant HCV (JFH1, 2a) vaccinia virus. CONCLUSIONS: Our data suggest that a rAd5-CE1E2-based HCV vaccine would be capable of eliciting an effective immune response and cross-protection. These findings have important implications for the development of T cell-based HCV vaccine candidates

    Luminescent biodegradable polycaprolactone materials prepared by blending with bio-based hyperbranched polymers

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    Evaluation of dry eye disease symptomatology and mental health status among patients with different COVID-19 statuses

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    AIM: To evaluate dry eye disease (DED) symptomatology and mental health status in different COVID-19 patients. METHODS: A cross-sectional observational design was used. Totally 123 eligible adults (46.34% of men, age range, 18-59y) with COVID-19 included in the study from August to November, 2022. Ocular Surface Disease Index (OSDI), Five-item Dry Eye Questionnaire (DEQ-5), Hospital Anxiety and Depression Scale (HADS), and Pittsburgh Sleep Quality Index (PSQI) were used in this study. RESULTS: OSDI scores were 6.82 (1.25, 15.91) in asymptomatic carriers, 7.35 (2.50, 18.38) in mild cases, and 16.67 (4.43, 28.04) in recurrent cases, with 30.00%, 35.56%, and 57.89%, respectively evaluated as having DED symptoms (χ2=7.049, P=0.029). DEQ-5 score varied from 2.00 (0, 6.00) in asymptomatic carriers, 3.00 (0, 8.00) in mild cases, and 8.00 (5.00, 10.00) in recurrent cases, with 27.50%, 33.33%, and 55.26%, respectively assessed as having DED symptoms (χ2=8.532, P=0.014). The prevalence of clinical anxiety (50.00%) and depression (47.37%) symptoms were also significantly higher in patients with recurrent infection (χ2=24.541, P<0.001; χ2=30.871, P<0.001). Recurrent infection was a risk factor for high OSDI scores [odds ratio, 2.562; 95% confidence interval (CI), 1.631-7.979; P=0.033] and DEQ-5 scores (odds ratio, 3.353; 95%CI, 1.038-8.834; P=0.043), whereas having a fixed occupation was a protective factor for OSDI scores (odds ratio, 0.088; 95%CI, 0.022-0.360; P=0.001) and DEQ-5 scores (odds ratio, 0.126; 95%CI, 0.039-0.405; P=0.001). CONCLUSION: Patients with recurrent COVID-19 have more severe symptoms of DED, anxiety, and depression
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