Vela pulsar wind nebula X-rays are polarized to near the synchrotron limit.

Pulsar wind nebulae are formed when outflows of relativistic electrons and positrons hit the surrounding supernova remnant or interstellar medium at a shock front. The Vela pulsar wind nebula is powered by a young pulsar (B0833-45, aged 11,000 years)1 and located inside an extended structure called Vela X, which is itself inside the supernova remnant2. Previous X-ray observations revealed two prominent arcs that are bisected by a jet and counter jet3,4. Radio maps have shown high linear polarization of 60% in the outer regions of the nebula5. Here we report an X-ray observation of the inner part of the nebula, where polarization can exceed 60% at the leading edge-approaching the theoretical limit of what can be produced by synchrotron emission. We infer that, in contrast with the case of the supernova remnant, the electrons in the pulsar wind nebula are accelerated with little or no turbulence in a highly uniform magnetic field.

Skills transfer from the DaVinci® system to the Hugo™ RAS system.

PURPOSE: Recently, the robotic surgical system, Hugo™ was approved for clinical use. The transfer of skills is important for understanding the implementation of surgical innovation. We explored the transfer of skills from the DaVinci® to the Hugo™ by studying the learning curve and short-term patient outcomes during radical prostatectomy (RARP). METHODS: We examined the transfer of skills from one surgeon performing RARP from the first case with the Hugo™ system in April 2022. The surgeon had previously performed > 1000 RARPs using DaVinci®. Perioperative and clinical outcomes were collected for procedures on both Hugo™ and DaVinci®. Patient follow-up time was 3 months. RESULTS: Nineteen Hugo™ cases and 11 DaVinci® cases were recorded. No clinically relevant difference in procedure time was found when transferring to Hugo™. Patients operated using Hugo™ had more contacts postoperatively compared to the DaVinci®, all Clavien-Dindo (CD) grade 1 (53% vs 18%). Three patients from the Hugo™ group were re-admitted within 30 days with catheter malfunction (CD grade 1), infection without a focus (CD grade 2), and ileus due to a hernia in the port hole (CD grade 3b). The 3-month follow-up showed similar results in prostate-specific antigen levels (PSA) and erectile dysfunction between the two robotic systems, but a higher incidence of incontinence was found for the Hugo™. CONCLUSION: We observed that the skills of an experienced robotic surgeon are transferable from DaVinci® to Hugo™ when performing RARP. No obvious benefits were found for using Hugo™ compared to DaVinci® for RARP although this needs confirmatory studies.

A case for a binary black hole system revealed via quasi-periodic outflows.

Binaries containing a compact object orbiting a supermassive black hole are thought to be precursors of gravitational wave events, but their identification has been extremely challenging. Here, we report quasi-periodic variability in x-ray absorption, which we interpret as quasi-periodic outflows (QPOuts) from a previously low-luminosity active galactic nucleus after an outburst, likely caused by a stellar tidal disruption. We rule out several models based on observed properties and instead show using general relativistic magnetohydrodynamic simulations that QPOuts, separated by roughly 8.3 days, can be explained with an intermediate-mass black hole secondary on a mildly eccentric orbit at a mean distance of about 100 gravitational radii from the primary. Our work suggests that QPOuts could be a new way to identify intermediate/extreme-mass ratio binary candidates.

Inguinal metastases from testicular cancer.

OBJECTIVE: To evaluate the incidence of inguinal metastases in patients with testicular cancer and relapse after initial stage I disease. PATIENTS AND METHODS: Of 695 patients, 14 (2%) with stage I testicular cancer developed inguinal metastases during the follow-up on a surveillance programme. At orchidectomy, one patient had involvement of the tunica albuginea and one a history of cryptorchidism and development of testicular cancer on the contralateral side. The remaining patients had no history of previous surgery in the inguinal region or in the scrotal area, or any other known risk factors for developing inguinal-node metastases. Two patients had a seminoma (0.5%) and 12 (4%) a nonseminoma. The histopathological examination showed that the metastases were in lymph nodes in four patients, the remainder having a more diffuse involvement of the tissue in the inguinal region. At relapse, patients were treated by three or four cycles of bleomycin, etoposide and cisplatin, except those with low-stage seminomas (stage IIa and IIb), who were treated by radiation therapy. RESULTS: All patients had a complete remission after treatment with chemotherapy or radiotherapy. No patients died or developed a recurrence during the median follow-up of 72 months. CONCLUSION: Metastases to the inguinal region are found in approximately 2% of patients with testicular cancer; about a quarter have lymph-node metastases, the rest probably having metastases to the spermatic cord with direct invasion into the surrounding tissue. High ligation of the spermatic cord is therefore important. Chemotherapy for patients with nonseminoma and radiotherapy for patients with seminoma gives excellent results.