Cross-species transmission of viruses from wildlife animal reservoirs poses a marked threat to human and animal health
. Bats have been recognized as one of the most important reservoirs for emerging ...viruses and the transmission of a coronavirus that originated in bats to humans via intermediate hosts was responsible for the high-impact emerging zoonosis, severe acute respiratory syndrome (SARS)
. Here we provide virological, epidemiological, evolutionary and experimental evidence that a novel HKU2-related bat coronavirus, swine acute diarrhoea syndrome coronavirus (SADS-CoV), is the aetiological agent that was responsible for a large-scale outbreak of fatal disease in pigs in China that has caused the death of 24,693 piglets across four farms. Notably, the outbreak began in Guangdong province in the vicinity of the origin of the SARS pandemic. Furthermore, we identified SADS-related CoVs with 96-98% sequence identity in 9.8% (58 out of 591) of anal swabs collected from bats in Guangdong province during 2013-2016, predominantly in horseshoe bats (Rhinolophus spp.) that are known reservoirs of SARS-related CoVs. We found that there were striking similarities between the SADS and SARS outbreaks in geographical, temporal, ecological and aetiological settings. This study highlights the importance of identifying coronavirus diversity and distribution in bats to mitigate future outbreaks that could threaten livestock, public health and economic growth.
Marangoni‐effect‐driven actuators (MDAs) have the advantages of direct light‐to‐work conversion and convenient operation, which makes it widely researched in the cutting‐edge fields including robots, ...micromachines, and intelligent systems. However, the MDA relies on the surface tension difference and it only works on the 2D liquid–air interface. Besides, the MDAs are normally pure black due to the light‐absorption material limitation. Herein, a transparent light‐driven 3D movable actuator (LTMA) and a 3D manipulation strategy are proposed. The LTMA is composed of photothermal nanoparticles‐doped temperature‐responsive hydrogel, whose surface energy changes as the nanoparticles absorb light energy. The 3D manipulation strategy combines Marangoni effect with photothermal buoyancy flow for realizing complex self‐propellant and floating/sinking motions. The LTMA can perform more advanced tasks such as 3D obstacle avoidance and 3D sampling. Benefiting from the porous structure of hydrogel, LTMA can naturally absorb the chemical molecules for remote sampling and automated drug delivery. The light‐driven, transparent, three‐dimensionally movable, and programmable actuator has promising prospects in the field of micromachines and intelligent systems.
A transparent light‐driven 3D actuator (LTMA) is prepared using hydrogel and photothermal nanoparticles. The LTMA can not only realize the propulsion movements on the liquid‐air interface based on Marangoni effect but also can realize the floating/sinking motions based on the photo‐thermal buoyancy flow. The LTMA with programmable controllability has promising prospects in the field of micromachines and intelligent systems.
Microplastics in bivalves have caused widespread concern due to their potential health risk to humans. In this study, microplastics in the digestive systems of four locally cultured bivalve species ...(scallop Chlamys farreri, mussel Mytilus galloprovincialis, oyster Crassostrea gigas, and clam Ruditapes philippinarum) in Qingdao, China, were analyzed and detected in 233 out of 290 bivalve samples (80%) over four seasons. The microplastic abundance in four species of bivalves ranged between 0.5 and 3.3 items/individual or 0.3 and 20.1 items/g wet weight digestive system, with significant species-specific and region-specific differences but no season-specific differences. Microfiber was the most predominant shape of all microplastics found. Eighteen types of polymer with diameters between 7 and 5000 μm were identified by μ-FT-IR (505 of 587 suspected items identified as microplastics) with polyvinyl chloride (PVC) and rayon being the most abundant ones. Bivalves collected in summer contained more larger-sized microplastics. R. philippinarum accumulated more smaller-sized microplastics and showed different microplastic features compared with the other three species of bivalves. By comparing and analyzing the microplastic polymer types between each bivalve species and the ambient environment, microplastic in clam can best reflect the variability of microplastic polymer types in sediment among different areas. Mussels can reflect the variability of microplastic polymer types in water to an extent. Therefore, clam and mussel are recommended to serve as bioindicators for microplastic pollution in the sediment and water, respectively. The occurrence of microplastics pollution in bivalves worldwide is wide, and bivalves can act as the transporter of microplastics to humans. Our results suggest that bivalves have an important role as environmental bioindicators and the pollution of microplastics in bivalves needs attention.
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•Microplastic abundance in four species of bivalves showed no seasonal variations.•Microplastic features in bivalves showed regional and species differences.•Bivalves can act as the transporter of microplastics to humans.•The use of bivalves as bioindicators of microplastic pollution is suggested.
Abstract
Swift J1727.8–1613 is a black hole X-ray binary newly discovered in 2023. We perform spectral analysis with simultaneous Insight-HXMT, NICER, and NuSTAR observations when the source was ...approaching the hard intermediate state. Such a joint view reveals an additional hard component apart from the normally observed hard component with reflection in the spectrum, to be distinguished from the usual black hole X-ray binary systems. By including this extra component in the spectrum, we have measured a high spin of
0.98
−
0.07
+
0.02
and an inclination of around
40
−
0.8
+
1.2
°, which is consistent with NICER results reported before. However, we find that the additional spectral component cannot be exclusively determined due to the model degeneracy. Accordingly, a possible jet/corona configuration is adjusted to account for the spectral fitting with different model trials. The extra component may originate either from a relativistic jet or a jet base/corona underneath a slow jet.
Abstract
The black hole candidate system SLX 1746–331 was back to business in 2023, after a long silence of roughly 13 years. An outburst was observed thoroughly by Insight-HXMT and NICER. The ...outburst is characterized by spectral dominance of the soft state, where the joint Insight-HXMT and NICER spectral analysis shows the temperature dependence of the disk flux follows
T
in
3.98
, and thus suggests that the inner disk reaches its innermost stable circular orbit during almost the entire outburst. By assuming 0.3
L
Edd
for the peak flux and an inclination angle of zero degrees, the lower limit of the compact object hosted in this system is estimated as 3.28 ± 2.14
M
⊙
. We also look into the relation between the disk temperature and disk flux for a sample of black hole systems, and by taking the disk temperature derived in the outburst of SLX 1746–331, such a relation results in a mass estimation of 5.2 ± 4.5
M
⊙
. Finally, the spin of the compact object is constrained to be larger than 0.8 with the spectral model KERRBB.
Abstract
The detection of cyclotron resonance scattering features (CRSFs) is the only way to directly and reliably measure the magnetic field near the surface of a neutron star (NS). The broad energy ...coverage and large collection area of Insight-HXMT in the hard X-ray band allowed us to detect the CRSF with the highest energy known to date, reaching about 146 keV during the 2017 outburst of the first galactic pulsing ultraluminous X-ray source (pULX) Swift J0243.6+6124. During this outburst, the CRSF was only prominent close to the peak luminosity of ∼2 × 10
39
erg s
−1
, the highest to date in any of the Galactic pulsars. The CRSF is most significant in the spin-phase region corresponding to the main pulse of the pulse profile, and its centroid energy evolves with phase from 120 to 146 keV. We identify this feature as the fundamental CRSF because no spectral feature exists at 60–70 keV. This is the first unambiguous detection of an electron CRSF from an ULX. We also estimate a surface magnetic field of ∼1.6 × 10
13
G for Swift J0243.6+6124. Considering that the dipole magnetic field strengths, inferred from several independent estimates of magnetosphere radius, are at least an order of magnitude lower than our measurement, we argue that the detection of the highest-energy CRSF reported here unambiguously proves the presence of multipole field components close to the surface of the neutron star. Such a scenario has previously been suggested for several pulsating ULXs, including Swift J0243.6+6124, and our result represents the first direct confirmation of this scenario.
Abstract We study the spectral and temporal properties of the black hole (BH) X-ray transient binary SLX 1746–331 during the 2023 outburst with NICER, NuSTAR, and Insight-HXMT observations. Through ...the joint fitting of the spectra from NICER, NuSTAR, and Insight-HXMT, the spin and inclination angles are measured for the first time as 0.85 ± 0.03 and 53° ± 0.°5, respectively. Accordingly, the mass of the compact star is updated from the previous lower limit of 3.3 ± 2.1 M ⊙ to 5.5 ± 3.6 M ⊙ , which is consistent with 5.2 ± 4.5 M ⊙ measured with an empirical mass–luminosity correlation of BH samples. With more NICER observations covering the later decay of the outburst, we confirm that the entire outburst was dominated by the disk emissions, and the thermal spectrum follows F ∝ T in 3.974 ± 0.003 , until a luminosity of over 2 magnitudes lower than the maximum of the outburst.
A green synthesis strategy of 2‐arylquinoxalines and 3‐arylquinoxalin‐2(1H)‐ones via ball milling, which could avoid copious solvent waste, was accomplished in this work. Aryl radicals were produced ...from aryldiazonium salts by using a solvent‐free or catalyst‐free single electron transfer process induced by mechanical force, affording a series of 2‐arylquinoxalines and 3‐arylquinoxalin‐2(1H)‐ones with 28%–85 yield.
Abstract
Staying in quiescence for 49 yr, 4U 1730–22 became active and had two outbursts in 2021 and 2022; 10 thermonuclear X-ray bursts were detected with Insight-HXMT. Among them, the faintest ...burst showed a double-peaked profile, placing the source as the seventh accreting neutron star (NS) exhibiting double-peaked type I X-ray bursts; the other bursts showed photospheric radius expansion (PRE). The properties of a double-peaked non-PRE burst indicate that it could be related to a stalled burning front. For the five bright PRE bursts, apart from the emission from the neutron star (NS) surface, we find the residuals both in the soft (<3 keV) and hard (>10 keV) X-ray bands. Time-resolved spectroscopy reveals that the excess can be attributed to an enhanced preburst/persistent emission or the Comptonization of the burst emission by the corona. We find, the burst emission shows a rise until the photosphere touches down to the NS surface rather than the theoretical predicted constant Eddington luminosity. The shortage of the burst emission in the early rising phase is beyond the occlusion by the disk. We speculate that the findings above are due to that the obscured part (not only the lower part) of the NS surface is exposed to the line of sight due to the evaporation of the obscured material by the burst emission, or the burst emission is anisotropic (
ξ
> 1) in the burst early phase. In addition, based on the fluxes of PRE bursts at their touchdown times, we derive a distance estimation as 9.0–12.4 kpc.
A
bstract
The previous studies of the island and double holography mainly focus on codimension-one branes. This paper explores the island on the codimension-two brane in AdS/dCFT. The codimension-two ...brane is closely related to conical singularity, which is very different from the codimension-one brane. We analyze the mass spectrum of gravitons on the codimension-two brane and find that the larger the brane tension is, the smaller the gravitational mass is. The massless mode is forbidden by either the boundary or normalization conditions. We prove that the first massive gravitational mode is located on the codimension-two brane; the larger the tension, the better the localization. It is similar to the case of codimension-one brane and builds an excellent physical foundation for the study of black hole evolution on codimension-two branes. We find that the Page curve of eternal black holes can be recovered due to the island ending on the codimension-two brane. The new feature is that the extremal surface passing the horizon cannot be defined after some finite time in the no-island phase. Fortunately, this unusual situation does not affect the Page curve since it happens after Page time.
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