Video Observations of Tiny Near-Earth Objects with Tomo-e Gozen

We report the results of video observations of tiny (diameter less than 100 m) near-Earth objects (NEOs) with Tomo-e Gozen on the Kiso 105 cm Schmidt telescope. A rotational period of a tiny asteroid reflects its dynamical history and physical properties since smaller objects are sensitive to the YORP effect. We carried out video observations of 60 tiny NEOs at 2 fps from 2018 to 2021 and successfully derived the rotational periods and axial ratios of 32 NEOs including 13 fast rotators with rotational periods less than 60 s. The fastest rotator found during our survey is 2020 HS7 with a rotational period of 2.99 s. We statistically confirmed that there is a certain number of tiny fast rotators in the NEO population, which have been missed with any previous surveys. We have discovered that the distribution of the tiny NEOs in a diameter and rotational period (D-P) diagram is truncated around a period of 10 s. The truncation with a flat-top shape is not explained well either by a realistic tensile strength of NEOs or suppression of YORP by meteoroid impacts. We propose that the dependence of the tangential YORP effect on the rotational period potentially explains the observed pattern in the D-P diagram.Comment: This article is published in PASJ as open access, published by OUP (https://doi.org/10.1093/pasj/psac043). 27 pages, 16 figure

Controlling bleeding during uniportal thoracoscopic major pulmonary resection

Aim: In uniportal thoracoscopic major pulmonary resection, it is important to appropriately manage significant vessel injury, to ensure patient safety and minimize conversion to thoracotomy. We analyzed cases of significant vessel injury and investigated efficacy of an algorithm to manage bleeding during thoracoscopic uniportal major pulmonary resection.Methods: A total of 169 patients underwent “uniportal thoracoscopic major pulmonary resection” (lobectomy or segmentectomy) at our department between February 2019 and April 2021. These patients were classified into groups with (group A, n = 8) and without (group B, n = 161) intraoperative massive bleeding. Patient characteristics and perioperative results were compared between the two groups. Patients with significant vessel injury and conversion to thoracotomy were analyzed in detail.Results: Group B had significantly less blood loss (A: 197 ± 173 g; B: 42 ± 74 g, P < 0.0001) and shorter-duration postoperative drainage (A: 2.6 ± 1.8 days; B: 1.6 ± 1.3 days, P = 0.036). There were no group differences in any other factors. The most frequently injured vessel in group A was the pulmonary artery (75%). Emergent conversion was required in four cases (cases 7, 76, 128, and 133; 2.4%) due to intraoperative bleeding. No patient developed catastrophic bleeding or required an intraoperative transfusion.Conclusion: We managed significant vessel injury appropriately during uniportal thoracoscopic major pulmonary resection using the troubleshooting algorithm. The algorithm for the uniportal approach was considered effective and easy to apply even by less-experienced surgeons

Ten-year-plus Postoperative Survivors of Primary Lung Cancer with Postoperative Recurrence

Journal Articl

Schwannoma arising in a lymph node mimicking metastatic pulmonary carcinoma

Schwannomas commonly arise in the torso, extremities, and mediastinum. However, no interlobar lymph node (#11i) lesions have ever been reported. This is a thought-provoking case, because it involved a schwannoma arising in a lymph node mimicking metastatic pulmonary carcinoma. A 72-year-old man was diagnosed with primary pulmonary carcinoma, and 18F-fluorodeoxyglucose (FDG) positron emission tomography demonstrated high FDG uptake in the primary lesion and in #11i, which suggested metastasis (clinical stage IIA). A right lower lobectomy with lymph node dissection was performed. Fortunately, the enlarged #11i was a schwannoma and not metastasis. The take-home message is “a patient with multiple neuromatosis tends to have schwannomas throughout the body”. Keywords: Schwannoma, Lymph node metastasis, Lung cancer, Positron emission tomograph