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The LIGO detection of gravitational waves (GW) from merging black holes in 2015 marked the beginning of a new era in observational astronomy. The detection of an electromagnetic signal from a GW source is the critical next step to explore in detail the physics involved. The Antarctic Survey Telescopes (AST3), located at Dome A, Antarctica, is uniquely situated for rapid response time-domain astronomy with its continuous night-time coverage during the austral winter. We report optical observations of the GW source (GW 170817) in the nearby galaxy NGC 4993 using AST3. The data show a rapidly fading transient at around 1 day after the GW trigger, with the i-band magnitude declining from 17.23 ± 0.13 magnitude to 17.72 ± 0.09 magnitude in ∼ 1.8 hour. The brightness and time evolution of the optical transient associated with GW 170817 are broadly consistent with the predictions of models involving merging binary neutron stars. We infer from our data that the merging process ejected about ∼ 10 −2 solar mass of radioactive material at a speed of up to 30% the speed of light.

Colorectal cancer is one of the leading causes of cancer-related mortality worldwide. Cancer stem cells are cell populations with stem cell nature presenting in tumor tissues and are the root of tumor formation and metastasis. CCND1 and E2F3 play important roles in cell cycle regulation. The 3'UTRs of CCND1 and E2F3 contain miR-449 binding sites. By transfecting pre-miR-449b and inhibiting miR-449b, we found that cell cycle, cell proliferation ability and cell cycle regulatory protein expression levels of colon cancer stem cells were altered. The correlation between CCND1, E2F3 and miR-449b showed that miR-449b could downregulate CCND1 and E2F3 expression. This, in turn, reduced the proliferative ability of colon cancer stem cells. These data suggest that miR-449b plays a tumor-suppressive role in colon cancer stem cells.

Two-dimensional (2D) carbide Ti 3 C 2 was synthesized by exfoliating Ti 3 AlC 2 in HF solution and used for supercapacitive performance investigation in 3 M KOH electrolyte. The specific surface area (SSA) of as-synthesized Ti 3 C 2 was 22.35 m 2 /g. Ti 3 C 2 -based supercapacitor electrodes exhibited good energy storage ability and had a volumetric capacitance 119.8 F/cm 3 at the current density of 2.5 A/g. Moreover, the addition of carbon black into Ti 3 C 2 powders greatly improved the performance of Ti 3 C 2 -based capacitors because carbon black restrained the preferred orientation of 2D Ti 3 C 2 , providing fast ion transport channels, and in turn, decreasing electrical resistance from 16.7 Ω to 3.5 Ω.