Previous nonhepatectomy abdominal surgery did not increase the difficulty in laparoscopic hepatectomy for hepatocellular carcinoma: A case-control study in 100 consecutive patients.

Objectives: Laparoscopic hepatectomy (LH) is still technically challenging for patients with previous nonhepatectomy abdominal surgery (AS). Therefore, this study aimed to assess the difficulty of performing LH for patients with hepatocellular carcinoma (HCC) and a history of nonhepatectomy AS during the initial developing period of LH. Materials and Methods: The retrospective study enrolled patients who were newly diagnosed with HCC receiving LH from January 2013 to June 2021. Demographic characteristics, perioperative variables, and surgical complications were prospectively collected. Results: One hundred patients were reviewed consecutively, comprising 23 in the AS group and 77 in the non-AS group. No significant differences were observed in median IWATE score (5 vs. 5, P = 0.194), operative time (219 vs. 200 min, P = 0.609), blood loss (100.0 vs. 200.0 mL, P = 0.734), transfusion rate (4.3% vs. 10.4%, P = 0.374), duration of parenchyma transection (90.0 vs. 72.4 min, P = 0.673), and mean nonparenchymal transection time (191.0 vs. 125.0 min, P = 0.228), without increasing the conversion rate (0.0% vs. 3.9%, P = 0.336), postoperative complications (30.3% vs. 33.8%, P = 0.488), and postoperative hospital stay (6 vs. 7 days, P = 0.060) in AS group and non-AS groups. Conclusion: History of previous nonhepatectomy AS can lead to longer nonparenchymal transection time instead of conversion and did not increase the difficulty. Prolonged nonparenchymal transection time did not increase the surgical complications, prolong the postoperative hospital stay, and compromise the survival outcomes.

Sub-second periodicity in a fast radio burst.

Fast radio bursts (FRBs) are millisecond-duration flashes of radio waves that are visible at distances of billions of light years1. The nature of their progenitors and their emission mechanism remain open astrophysical questions2. Here we report the detection of the multicomponent FRB 20191221A and the identification of a periodic separation of 216.8(1) ms between its components, with a significance of 6.5σ. The long (roughly 3 s) duration and nine or more components forming the pulse profile make this source an outlier in the FRB population. Such short periodicity provides strong evidence for a neutron-star origin of the event. Moreover, our detection favours emission arising from the neutron-star magnetosphere3,4, as opposed to emission regions located further away from the star, as predicted by some models5.

Dense magnetized plasma associated with a fast radio burst.

Fast radio bursts are bright, unresolved, non-repeating, broadband, millisecond flashes, found primarily at high Galactic latitudes, with dispersion measures much larger than expected for a Galactic source. The inferred all-sky burst rate is comparable to the core-collapse supernova rate out to redshift 0.5. If the observed dispersion measures are assumed to be dominated by the intergalactic medium, the sources are at cosmological distances with redshifts of 0.2 to 1 (refs 10 and 11). These parameters are consistent with a wide range of source models. One fast burst revealed circular polarization of the radio emission, but no linear polarization was detected, and hence no Faraday rotation measure could be determined. Here we report the examination of archival data revealing Faraday rotation in the fast radio burst FRB 110523. Its radio flux and dispersion measure are consistent with values from previously reported bursts and, accounting for a Galactic contribution to the dispersion and using a model of intergalactic electron density, we place the source at a maximum redshift of 0.5. The burst has a much higher rotation measure than expected for this line of sight through the Milky Way and the intergalactic medium, indicating magnetization in the vicinity of the source itself or within a host galaxy. The pulse was scattered by two distinct plasma screens during propagation, which requires either a dense nebula associated with the source or a location within the central region of its host galaxy. The detection in this instance of magnetization and scattering that are both local to the source favours models involving young stellar populations such as magnetars over models involving the mergers of older neutron stars, which are more likely to be located in low-density regions of the host galaxy.