Abstract
We report on multi-wavelength monitoring observations of an M-dwarf flare star AD Leonis with the Seimei Telescope (6150–7930 Å), SCAT (Spectroscopic Chuo-university Astronomical Telescope; ...3700–7500 Å), and NICER (Neutron Star Interior Composition Explorer; 0.2–12.0 keV), with the collaboration of the OISTER (Optical and Infrared Synergetic Telescopes for Education and Research) program. Twelve flares are detected in total, including ten Hα, four X-ray, and four optical-continuum flares; one of them is a superflare with a total energy of ∼2.0 × 1033 erg. We found that: (1) during the superflare, the Hα emission line full width at 1/8 maximum dramatically increases to 14 Å from 8 Å in the low-resolution spectra (R ∼ 2000) accompanied by large white-light flares, (2) some weak Hα/X-ray flares are not accompanied by white-light emissions, and (3) the non-flaring emissions show clear rotational modulations in X-ray and Hα intensity in the same phase. To understand these observational features, one-dimensional hydrodynamic flare simulations are performed using the RADYN code. We find the simulated Hα line profiles with hard and high-energy non-thermal electron beams to be consistent with the initial phase line profiles of the superflares, while those with a softer and/or weak-energy beam are consistent with those in decay phases, indicating the changes in the energy fluxes injected to the lower atmosphere. Also, we find that the relation between the optical continuum and Hα intensity is nonlinear, which can be one cause of the non-white-light flares. The flare energy budget exhibits diversity in the observations and models, and more observations of stellar flares are necessary for constraining the occurrence of various emission line phenomena in stellar flares.
Abstract
Young solar-type stars are known to show frequent “superflares,” which may severely influence the habitable worlds on young planets via intense radiation and coronal mass ejections. Here we ...report an optical spectroscopic and photometric observation of a long-duration superflare on the young solar-type star EK Draconis (50–120 Myr age) with the Seimei telescope and Transiting Exoplanet Survey Satellite. The flare energy 2.6 × 10
34
erg and white-light flare duration 2.2 hr are much larger than those of the largest solar flares, and this is the largest superflare on a solar-type star ever detected by optical spectroscopy. The H
α
emission profile shows no significant line asymmetry, meaning no signature of a filament eruption, unlike the only previous detection of a superflare on this star. Also, it did not show significant line broadening, indicating that the nonthermal heating at the flare footpoints is not essential or that the footpoints are behind the limb. The time evolution and duration of the H
α
flare are surprisingly almost the same as those of the white-light flare, which is different from general M-dwarf (super-)flares and solar flares. This unexpected time evolution may suggest that different radiation mechanisms than general solar flares are predominant, such as: (1) radiation from (off-limb) flare loops and (2) re-radiation via radiative back-warming, in both of which the cooling timescales of flare loops could determine the timescales of H
α
and white light.
Chemical pleurodesis is performed in pneumothorax patients to treat nonresolving air leakage or prevent recurrence. However, factors that might predict the need for chemical pleurodesis remain ...unknown. Therefore, this study investigated predictive factors for the application of chemical pleurodesis for pneumothorax.We retrospectively analyzed 401 adult pneumothorax patients who underwent chest tube drain insertion during hospitalization at Fukujuji Hospital from January 2016 to December 2020. The patients were divided into 3 groups: the pleurodesis group, comprising 89 patients treated with chemical pleurodesis; the nonpleurodesis group, comprising 206 patients treated without chemical pleurodesis; and the surgical group, comprising 106 patients treated surgically. Data for patients in the pleurodesis group were compared to those in the nonpleurodesis or surgical group, and a predictive score of the application of chemical pleurodesis for pneumothorax was developed.Compared with the nonpleurodesis group, in the pleurodesis group, patient age was higher (P < .001), emphysema (n = 33 (37.1%) vs 70 (34.0%), P = .045), and interstitial pneumonitis (n = 19 (21.3%) vs 19 (9.2%), P = .022) were more common causes, and chest tube suction was more common (n = 78 (87.96%) vs n = 123 (59.7%), P < .001). Similar results were found between the pleurodesis and surgical groups. We developed a score for predicting the application of chemical pleurodesis for pneumothorax, including the following factors: age ≥55 years; presence of emphysema and/or interstitial pneumonitis; and use of chest tube suction. The score for the pleurodesis group showed a high area under the receiver operating characteristic curve compared with that for the nonpleurodesis group (0.776 95% confidence interval: 0.725-0.827). With a score of 2 as the cutoff value, the sensitivity was 91.0% and the specificity was 52.4%. In a comparison between the pleurodesis and surgical groups, the predicting score showed the high AUC of 0.904 (95% confidence interval: 0.863-0.945).This study reveals predictive factors for the application of chemical pleurodesis and provides a predictive score including 3 factors.
Macrolide-resistant Mycobacterium avium complex pulmonary disease (MAC-PD) is difficult to treat. We have been performing surgical treatment for clarithromycin (CAM) -resistant MAC-PD. This study ...reviewed 14 patients who underwent pulmonary resection for CAM-resistant MAC-PD between January 2014 and December 2019 at our institution. The median period between the confirmation of CAM-resistance and surgery was 5.0 months. In addition to oral antibiotics, parenteral aminoglycoside was administered to all patients perioperatively. Preoperative sputum culture was positive in 11 patients. All patients underwent anatomical lung resection as follows: 5 lobectomies, 2 segmentectomies, 6 combined resections, and 1 pneumonectomy. One patient developed a bronchopleural fistula. A sputum-negative status was achieved in 12 patients after the surgery, all of whom showed no recurrence during the follow-up period. Two patients with bilateral bronchiectatic lesions failed to achieve negative conversion postoperatively. Both patients underwent contralateral surgery. One patient continued to be sputum-positive, and the other patient achieved a sputum-negative status. Resectional surgery combined with chemotherapy may be effective for patients with CAM-resistant MAC-PD.
Abstract Background Cardiac tamponade caused by coronary artery injury is an extremely rare postlobectomy complication. Herein, we present a case of cardiac tamponade due to coronary artery injury ...after a left upper lobectomy for lung cancer and discuss the possible cause of coronary artery injury. Case presentation An 82-year-old man with atrial fibrillation, emphysema, chronic heart failure-associated cardiomegaly, and a history of aortic stenting for an abdominal aortic aneurysm underwent a left upper lobectomy without mediastinal nodal dissection for lung cancer. Twenty-eight hours postoperatively, he lost consciousness and went into shock vitals; computed tomography revealed cardiac tamponade. Emergency surgery was performed, which revealed a left circumflex artery laceration. Although the laceration was successfully repaired, he had a gastrointestinal perforation and developed septic shock. He died 35 days after the lung surgery. Intraoperative injury to the heart cannot be ruled out, but the site of the coronary artery injury was located far from the hilum outside the surgical field during the lobectomy. Three-dimensional computed tomography showed that the site of injury was close to the multiple firing junction of the staples that divided the anterior interlobar fissure. Two staples at the multiple firing junction, which protruded perpendicularly to the cut surface, could injure the coronary artery. Conclusion Although we cannot rule out the possibility that the intraoperative manipulation procedures contributed to the coronary artery injury, we speculate that the protruding staples might penetrate the pericardium after lung expansion and eventually injured the coronary artery.
The possible association between maternal exposure to pyrethroid insecticides (PYRs) during pregnancy and infant development was explored. Levels of exposure to PYRs was assessed by metabolite ...(3-phenoybenzoic acid, 3-PBA) concentration in maternal spot urine sampled in the first trimester of index pregnancy, and infant development was assessed at 18 months of age using the Kinder Infants Development Scale (KIDS), which is based on a questionnaire to the caretaker. The relationship between KIDS score and maternal urinary 3-PBA levels was examined by a stepwise multiple regression analysis using biological attributes of the mother and infant, breast feeding, and nursing environment as covariates. The analysis extracted 3-PBA and the nursing environment as significant to explain the KIDS score at 18 months of age with positive partial regression coefficients. Inclusion of fish consumption frequency of the mother during pregnancy as an independent variable resulted in the selection of fish consumption as significant, while the two variables were marginally insignificant but still with a positive coefficient with the KIDS score. The result suggested a positive effect of maternal PYR exposure on infant development, the reason for which is not clear, but an unknown confounding factor is suspected.
We present optical observations of the Type Ia supernova (SN) 2019ein, starting two days after the estimated explosion date. The spectra and light curves show that SN 2019ein belongs to a ...high-velocity (HV) and broad-line group with a relatively rapid decline in the light curves (Δm15(B) = 1.36 0.02 mag) and a short rise time (15.37 0.55 days). The Si ii λ6355 velocity, associated with a photospheric component but not with a detached high-velocity feature, reached ∼20,000 km s−1 12 days before the B-band maximum. The line velocity, however, decreased very rapidly and smoothly toward maximum light, to ∼13,000 km s−1, which is relatively low among HV SNe. This indicates that the speed of the spectral evolution of HV SNe Ia is correlated with not only the velocity at maximum light, but also the light-curve decline rate, as is the case for normal-velocity (NV) SNe Ia. Spectral synthesis modeling shows that the outermost layer at >17,000 km s−1 is well described by an O-Ne-C burning layer extending to at least 25,000 km s−1, and there is no unburnt carbon below 30,000 km s−1; these properties are largely consistent with the delayed detonation scenario and are shared with the prototypical HV SN 2002bo despite the large difference in Δm15(B). This structure is strikingly different from that derived for the well-studied NV SN 2011fe. We suggest that the relation between the mass of 56Ni (or Δm15) and the extent of the O-Ne-C burning layer provides an important constraint on the explosion mechanism(s) of HV and NV SNe.
Abstract
Background
An amyloidoma is defined as a solitary, localized, tumor-like deposit of amyloid in the absence of systemic amyloidosis. Amyloidomas occur most frequently in the bladder, followed ...by the lungs, trachea and bronchi, larynx and vocal cords, tonsils, conjunctivae, orbits, lymph nodes, gastrointestinal tract, and skin. It is extremely rare for an amyloidoma to present in the chest wall. Indeed, only 5 cases of chest wall amyloidoma have been reported. Moreover, all reported lesions were > 10 cm in size and involved the ribs. Herein, we report our experience with a patient who had a chest wall amyloidoma 3 cm in diameter without rib involvement.
Case presentation
A 3.1 × 1.5-cm tumor situated in the fifth intercostal space of the chest wall was found in an 83-year-old male during a routine health checkup. Chest magnetic resonance imaging showed a mass of intermediate intensity on T1-weighted imaging and low intensity on T2-weighted imaging with heterogeneous contrast enhancement. The tumor was resected during video-assisted thoracoscopic surgery. No adhesions were observed between the tumor and the lung. The tumor was white, hard, elastic, and located in the extrapleural fat without bone involvement. The tumor was removed in a piecemeal fashion because the tumor was fragile and the surgical margin was unclear. A wide resection was achieved, including the intercostal muscle. Pathologic examination of the tumor using Dylon and Congo red staining confirmed amyloid deposition with tumor spread from the fat to the intercostal muscle and vascular walls but no pleural invasion. Without clear evidence of systemic amyloidosis, this patient was diagnosed with an amyloidoma of the chest wall. The postoperative course was uneventful, and he is doing well 1 year after surgery.
Conclusion
Amyloidoma of the chest wall can present in various ways. An amyloidoma can be a small tumor, as in our patient, or the amyloidoma can be a large, destructive mass with rib involvement. Diagnosis of an amyloidoma should be kept in mind when patients present with chest wall tumors because an amyloidoma can be characterized by invasion within the chest wall independent of size.
Purpose: To investigate the exercise capacity and health-related quality of life (HRQOL) of surgical patients with nontuberculous mycobacterial pulmonary disease (NTM-PD) preoperatively versus 6 ...months postoperatively.Methods: This prospective observational study included patients with NTM-PD and was conducted at a single center. The intervention was surgical resection plus perioperative and post-discharge physical therapy. The physical function was assessed preoperatively and 6 months postoperatively using the 6-minute walk test (6MWT). HRQOL was assessed preoperatively and 6 months postoperatively using the Short-Form 36 (SF-36) health survey questionnaire and St. George’s Respiratory Questionnaire. The postoperative HRQOL was compared between patients with and without preoperative clinical symptoms.Results: In total, 35 patients were analyzed. The preoperatively symptomatic group had significantly lower preoperative HRQOL than the preoperatively asymptomatic group (p <0.05). Compared with preoperatively, there were significant improvements at 6 months postoperatively in the 6MWT (p <0.01) and HRQOL, mainly in the SF-36 mental component summary (p <0.01). The SF-36 mental component summary in the preoperatively symptomatic group was very significantly improved from preoperatively to 6 months postoperatively (p <0.05).Conclusion: The combination of surgical treatment and physical therapy for NTM-PD contributes to improvements in physical function and HRQOL.
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