The gravitational wave (GW) as a standard siren directly determines the luminosity distance from the gravitational waveform without reference to the specific cosmological model, of which the redshift can be obtained separately by means of the electromagnetic counterpart like GW events from binary neutron stars and massive black hole binaries (MBHBs). To see to what extent the standard siren can reproduce the presumed dipole anisotropy written in the simulated data of standard siren events from typical configurations of GW detectors, we find that (1) for the Laser Interferometer Space Antenna with different MBHB models during five-year observations, the cosmic isotropy can be ruled out at 3σ confidence level (C.L.) and the dipole direction can be constrained roughly around 20% at 2σ C.L., as long as the dipole amplitude is larger than 0.03, 0.06 and 0.025 for MBHB models Q3d, pop III and Q3nod with increasing constraining ability, respectively; (2) for Einstein Telescope with no less than 200 standard siren events, the cosmic isotropy can be ruled out at 3σ C.L. if the dipole amplitude is larger than 0.06, and the dipole direction can be constrained within 20% at 3σ C.L. if the dipole amplitude is near 0.1; (3) for the Deci-Hertz Interferometer Gravitational wave Observatory with no less than 100 standard siren events, the cosmic isotropy can be ruled out at 3σ C.L. for dipole amplitude larger than 0.03 , and the dipole direction can even be constrained within 10% at 3σ C.L. if the dipole amplitude is larger than 0.07. Our work manifests the promising perspective of the constraint ability on the cosmic anisotropy from the standard siren approach.

Geraniin, a polyphenolic component isolated from Phyllanthus amarus, has been reported to possess diverse biological activities, including antitumor, antiinflammatory, antihyperglycemic, antihypertensive, and antioxidant. However, the role and underlying mechanisms of geraniin in colorectal cancer still remain unclear. In the present study, we found that geraniin notably inhibited cell proliferation and clonogenic formation of colorectal cancer cell SW480 and HT-29 in a dose-dependent manner by Cell Counting Kit 8, EdU, and colony formation assays, respectively. Additionally, geraniin remarkably induced apoptosis of SW480 and HT-29 cells in a dose-dependent way by Hoechst 33342 staining, flow cytometric analysis, and TdT-mediated dUTP nick-end labeling assays and increased the expressions of Bax, caspase-3, and caspase-9, while decreased the level of Bcl-2. Besides, wound healing, transwell migration, and invasion assays demonstrated that geraniin obviously inhibited the migration and invasion of SW480 and HT-29 cells. Moreover, it also inhibited the levels of phospho (p)-phosphatidylinositol 3-kinase and p-Akt. Furthermore, in-vivo animal study revealed that geraniin had the significant inhibitory effects on tumor growth and promoted cancer cell apoptosis remarkably, which further confirmed the antitumor effect of geraniin. Taken together, the present study exhibited the positive role of geraniin in inhibiting proliferation and inducing apoptosis through suppression of phosphatidylinositol 3-kinase/Akt pathway in colorectal cancer cells in vitro and in vivo, which might provide new insights in searching for new drug candidates of anticolorectal cancer.

A preliminary estimation of gravitational waves (GWs) from the extreme-mass-ratio-inspirals (EMRIs) system in the Galactic Centre (GC) is given for the 37 observed S-stars revolving around the supermassive black hole (SMBH) at Sagittarius (Sgr) A*. Within this century, the total strain of the gravitational waveform calculated from the post-Newtonian (PN) method with eccentricity is well below the current planned sensitivity of pulsar-timing-array (PTA). New technology might be required in order to extract GW signal from this EMRIs system for future PTA detections.

Recently it was shown that cosmic anisotropy can be well tested using either standard siren measurement of luminosity distance d L (z) from gravitational-wave (GW) observation or dispersion measure (DM(z)) from fast radio burst (FRB). It was also observed that the combined measurement of d L (z) · DM(z) from the GW/FRB association system as suggested in some of FRB models is more effective to constrain cosmological parameters than d L (z) or DM(z) separately. In this paper, we show that this upgraded siren from the combined GW/FRB observations could test cosmic anisotropy with a double relative sensitivity compared to the usual standard siren from GW observations only.