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Background Emerging epidemiological evidence implicates pulmonary dysfunction in cardiovascular pathogenesis, yet its arrhythmogenic potential remains poorly defined. Objectives We aimed to assess the link between ventilatory parameters, pulmonary disease phenotypes and risk of incident arrhythmias across diverse populations. Methods We analyzed data from 17,684 adults in two prospective cohort studies-the Atherosclerosis Risk in Communities (ARIC; n = 12,929) and Cardiovascular Health Study (CHS; n = 4,755). Adjudicated arrhythmia diagnoses (atrial fibrillation/flutter [AF/AFL], ventricular arrhythmias [VAs], high-grade atrioventricular [AV] block, and premature atrial/ventricular complexes [PAC/PVC]) were identified via hospitalization records and mortality data. Multivariable-adjusted Cox proportional hazards models quantified associations between forced expiratory volume in 1 s (FEV1%) predicted and forced vital capacity (FVC%) predicted quartiles with arrhythmia risk, adjusting for traditional cardiovascular risk factors. Results Over a median follow-up of 12.6 years, impaired FEV1% and FVC% corresponded to a graded increase in arrhythmia risk. Compared to the highest quartile, the lowest FEV1% predicted quartile had elevated hazards for any arrhythmias (HR 1.32, 95% CI 1.23–1.42), AF/AFL (HR 1.68, 1.52–1.85), VAs (HR 1.55, 1.29–1.86), high-grade AV block (HR 1.37, 1.08–1.73), and PAC/PVC (HR 1.42, 1.20–1.69). Similar trends were observed for FVC% predicted quartiles. These associations remained consistent in never-smoking individuals and across cohorts. Obstructive spirometry pattern was associated with the strongest arrhythmia risk, while restrictive ventilatory patterns showed relatively lower risk elevations. No association was observed with sick sinus syndrome. Conclusions Reduced pulmonary function suggested independent associations with incident arrhythmias across supraventricular, ventricular, and conduction system pathologies in two historical cohorts. These findings suggest that spirometric indices could potentially represent novel independent indicators for arrhythmia development worthy of further validation in contemporary settings,, with associations distinct from conventional cardiometabolic risk factors.

Objective To investigate the feasibility and necessity of endoscopic thyroidectomy with central lymph node dissection via the combined breast and trans-oral approaches. Methods Six patients with papillary thyroid carcinoma who underwent endoscopic total thyroidectomy with central node dissection via combined breast and trans-oral approaches from November 2014 to January 2015 in Zhongshan Hospital, Xiamen University, were analyzed. Results After completion of endoscopic central lymph node dissection via the traditional breast approach, eight pieces of lymph nodes could still be dissected via the trans-oral approach. Two of these eight pieces were positive for thyroid cancer metastasis. Conclusions It is advisable to perform endoscopic central lymph node dissection for thyroid carcinoma via the breast approach combined with the trans-oral approach.

Water hyacinth and its ecological invasion have negative impacts on diversity of indigenous species and ecosystems, which becomes one of the hotspots in current ecological research. In this paper, a water hyacinth ecological system with two state-dependent impulse controls is studied. Firstly, we define the successor functions of semicontinuous dynamic system and give existence theorems of order-1 periodic solution and order-2 periodic solution of such system. Secondly, we analyze singular points of the system without impulsive state feedback control qualitatively and get the condition for focus point. Thirdly, we obtain the sufficient condition under which the system has an order-1 or order-2 periodic solution through the method of successor function and prove the stability of the order-1 or order-2 periodic solution by the analogue of Poincaré’s criterion. Furthermore, some examples and numerical simulations are given to illustrate our results.

Ultraluminous X-ray bursts (ULXBs) are ultraluminous X-ray flares with a fast rise (∼1 minute) and a slow decay (∼1 hour), which are commonly observed in extragalactic globular clusters. Most ULXBs are observational one-off bursts, whereas five flares from the same source in NGC 5128 were discovered by Irwin et al. In this article, we propose a neutron star (NS)–white dwarf (WD) binary model with super-Eddington accretion rates to explain the repeating behavior of the ULXB source in NGC 5128. With an eccentric orbit, the mass transfer occurs at the periastron where the WD fills its Roche lobe. The ultraluminous X-ray flares can be produced by the accretion column around the NS magnetic poles. On the other hand, some repeating fast radio bursts (FRBs) were also found in extragalactic globular clusters. Repeating ULXBs and repeating FRBs are the most violent bursts in the X-ray and radio bands, respectively. We propose a possible association between the repeating ULXBs and the repeating FRBs. Such an association is worth further investigation by follow-up observations on nearby extragalactic globular clusters.

We search for compact objects in binaries based on Gaia DR3. A sample of 10 targets is derived under the following conditions: the radial velocity variable, low temperature (T eff < 6000 K), high mass function (f(M 2) > 1M ⊙), and ellipsoidal-like light curves. Two targets have LAMOST spectroscopic observations, one of which is a double-lined spectroscopic binary. The observational data of seven targets are not self-consistent, since their photometric periods are even shorter than the theoretical minimum orbital periods calculated by the stellar parameters from Gaia DR3. After excluding these seven inconsistent targets and another target contaminated by a near-bright star, the remaining two targets may contain compact objects worth follow-up observations. This work may serve as an example to demonstrate the feasibility of searching for compact objects in the massive Gaia data.

We report a single-lined white dwarf–main-sequence binary system, LAMOST J172900.17+652952.8, which is discovered by the Large Sky Area Multi-Object Fibre Spectroscopic Telescope (LAMOST)’s medium-resolution time-domain surveys. The radial-velocity semi-amplitude and orbital period of the optical visible star are measured by using follow-up observations with the Palomar 200 inch telescope and light curves from the Transiting Exoplanet Survey Satellite (TESS). Thus the mass function of the invisible candidate white dwarf is derived, f(M 2) = 0.120 ± 0.003 M ⊙. The mass of the visible star is measured based on a spectral energy distribution fitting, M 1 = 0.81−0.06+0.07M⊙ . Hence, the mass of its invisible companion is M 2 ≳ 0.63 M ⊙. The companion ought to be a compact object rather than a main-sequence star owing to the mass ratio q = M 2/M 1 ≳ 0.78 and the single-lined spectra. The compact object is likely to be a white dwarf if the inclination angle is not small, i ≳ 40°. By using the Galaxy Evolution Explorer (GALEX) near-UV flux, the effective temperature of the white dwarf candidate is constrained as TeffWD ≲ 12,000–13,500 K. It is difficult to detect white dwarfs which are outshone by their bright companions via single-epoch optical spectroscopic surveys. Therefore, optical time-domain surveys can play an important role in unveiling invisible white dwarfs and other compact objects in binaries.

We present LAMOST J041920.07+072545.4 (hereafter J0419), a close binary consisting of a bloated, extremely low mass pre-white dwarf (pre-ELM WD) and a compact object with an orbital period of 0.607189 days. The large-amplitude ellipsoidal variations and the evident Balmer and He i emission lines suggest a filled Roche lobe and ongoing mass transfer. No outburst events were detected in the 15 years of monitoring of J0419, indicating a very low mass transfer rate. The temperature of the pre-ELM, Teff=5793−133+124K , makes it cooler than the known ELMs, but hotter than most cataclysmic variable donors. Combining the mean density within the Roche lobe and the radius constrained from our spectral energy distribution fitting, we obtain the mass of the pre-ELM, M 1 = 0.176 ± 0.014 M ⊙. The joint fitting of light and radial velocity curves yields an inclination angle of i=66.5−1.7+1.4 degrees, corresponding to a mass of the compact object of M 2 = 1.09 ± 0.05 M ⊙. The very bloated pre-ELM has a smaller surface gravity ( logg=3.9±0.01 , R 1 = 0.78 ± 0.02 R ⊙) than the known ELMs or pre-ELMs. The temperature and the luminosity ( Lbol=0.62−0.10+0.11L⊙ ) of J0419 are close to those of the main sequence, which makes the selection of such systems through the H-R diagram inefficient. Based on the evolutionary model, the relatively long period and small logg indicate that J0419 could be close to the “bifurcation period” in the orbital evolution, which makes J0419 a unique source to connect ELM/pre-ELM WD systems, wide binaries, and cataclysmic variables.

The near-Earth (within ∼100 pc) supernova explosions in the past several million years can cause the global deposition of radioactive elements (e.g., 60 Fe) on Earth. The remnants of such supernovae are too old to be easily identified. It is therefore of great interest to search for million-year-old near-Earth neutron stars or black holes, the products of supernovae. However, neutron stars and black holes are challenging to find even in our Solar neighbourhood if they are not radio pulsars or X-ray/ γ -ray emitters. Here we report the discovery of one of the nearest (127.7 ± 0.3 pc) neutron star candidates in a detached single-lined spectroscopic binary LAMOST J235456.73+335625.9 (hereafter J2354). Utilizing the time-resolved ground-based spectroscopy and space photometry, we find that J2354 hosts an unseen compact object with M inv being 1.4–1.6 M ⊙ . The follow-up Swift ultraviolet (UV) and X-ray observations suggest that the UV and X-ray emission is produced by the visible star rather than the compact object. Hence, J2354 probably harbours a neutron star rather than a hot ultramassive white dwarf. Two-hour exceptionally sensitive radio follow-up observations with Five-hundred-meter Aperture Spherical radio Telescope fail to reveal any pulsating radio signals at the 6 σ flux upper limit of 12.5 µJy. Therefore, the neutron star candidate in J2354 can only be revealed via our time-resolved observations. Interestingly, the distance between J2354 and our Earth can be as close as ∼ 50 pc around 2.5 million years (Myrs) ago, as revealed by the Gaia kinematics. Our discovery demonstrates a promising way to unveil the hidden near-Earth neutron stars in binaries by exploring the optical time domain, thereby facilitating understanding of the metal-enrichment history in our Solar neighbourhood.

Typically, neutron stars are discovered by observations at radio, X-ray or gamma-ray wavelengths. Unlike radio pulsar surveys and X-ray observations, optical time-domain surveys can unveil and characterize exciting but less explored non-accreting and/or non-beaming neutron stars in binaries. Here we report the discovery of such a neutron star candidate using the LAMOST spectroscopic survey. The candidate, designated LAMOST J112306.9 + 400736, is in a single-lined spectroscopic binary containing an optically visible M star. The star’s large radial velocity variation and ellipsoidal variations indicate a relatively massive unseen companion. Utilizing follow-up spectroscopy from the Palomar 200 in. telescope and high-precision photometry from the Transiting Exoplanet Survey Satellite, we measure a companion mass of 1.2 4 − 0.03 + 0.03 M ⊙ . Main-sequence stars with this mass are ruled out, leaving a neutron star or a massive white dwarf. Although a massive white dwarf cannot be excluded, the lack of UV excess radiation from the companion supports the neutron star hypothesis. Deep radio observations with the Five-hundred-meter Aperture Spherical radio Telescope (FAST) yielded no detections of either pulsed or persistent emission. J112306.9 + 400736 is not detected in numerous X-ray and gamma-ray surveys, suggesting that the neutron star candidate is not currently accreting and pulsing. Our work exemplifies the capability of discovering compact objects in non-accreting close binaries by synergizing optical time-domain spectroscopy and high-cadence photometry. A neutron star candidate in a close binary has been discovered using a radial velocity method and characterized with a variety of ground- and space-based telescopes. The system probably represents an underexplored population of non-accreting and/or non-beaming neutron stars.

Ultraluminous X-ray bursts (hereafter ULXBs) are ultraluminous X-ray flares with a fast rise (\\(\\) one minute) and a slow decay (\\(\\) an hour), which are commonly observed in extragalactic globular clusters. Most ULXBs are observational one-off bursts, whereas five flares from the same source in NGC 5128 were discovered by Irwin et al. (2016). In this Letter, we propose a neutron star (NS)-white dwarf (WD) binary model with super-Eddington accretion rates to explain the repeating behavior of the ULXB source in NGC 5128. With an eccentric orbit, the mass transfer occurs at the periastron where the WD fills its Roche lobe. The ultraluminous X-ray flares can be produced by the accretion column around the NS magnetic poles. On the other hand, some repeating fast radio bursts (hereafter FRBs) were also found in extragalactic globular clusters. Repeating ULXBs and repeating FRBs are the most violent bursts in the X-ray and radio bands, respectively. We propose a possible association between the repeating ULXBs and the repeating FRBs. Such an association is worth further investigation by follow-up observations on nearby extragalactic globular clusters.