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Abstract Human intestinal organoids (HIOs) are vital for modeling intestinal development, disease, and therapeutic tissue regeneration. However, their susceptibility to stress, immunological attack, and environmental fluctuations limits their utility in research and therapeutic applications. This study evaluated the effectiveness of temporary silk protein‐based layer‐by‐layer (LbL) nanoencapsulation technique to enhance the viability and functions of HIOs against common biomedical stressors, without compromising their native functions. Cell viability and differentiation capacity are assessed, finding that nanoencapsulation significantly improved HIO survival under the various environmental perturbations studied without compromising cellular functionality. Post‐stress exposures, the encapsulated HIOs still successfully differentiated into essential intestinal cell types such as enterocytes, goblet cells, enteroendocrine cells, and Paneth cells. Moreover, the silk nanocoatings effectively protected against environmental stressors such as ultraviolet (UV) light exposure, protease degradation, antibody binding, and cytokine‐induced inflammation. This nanoencapsulation technique shows promise for advancing HIO applications in disease modeling, drug testing, and potential transplantation therapies. 

Encapsulation of single cells is a powerful technique used in various fields, such as regenerative medicine, drug delivery, tissue regeneration, cell-based therapies, and biotechnology. It offers a method to protect cells by providing cytocompatible coatings to strengthen cells against mechanical and environmental perturbations. Silk fibroin, derived from the silkworm Bombyx mori, is a promising protein biomaterial for cell encapsulation due to the cytocompatibility and capacity to maintain cell functionality. Here, THP-1 cells, a human leukemia monocytic cell line, were encapsulated with chemically modified silk polyelectrolytes through electrostatic layer-by-layer deposition. The effectiveness of the silk nanocoating was assessed using scanning electron microscopy (SEM) and confocal microscopy and on cell viability and proliferation by Alamar Blue assay and live/dead staining. An analysis of the mechanical properties of the encapsulated cells was conducted using atomic force microscopy (AFM) nanoindentation to measure elasticity maps and cellular stiffness. After the cells were encapsulated in silk, an increase in their stiffness was observed. Based on this observation, we developed a mechanical predictive model to estimate the variations in stiffness in relation to the thickness of the coating. By tuning the cellular assembly and biomechanics, these encapsulations promote systems that protect cells during biomaterial deposition or processing in general. 

Abstract We report on the results of an image-based search for pulsar candidates toward the Galactic bulge. We used mosaic images from the MeerKAT radio telescope that were taken as part of a 173 deg²survey of the bulge and Galactic center of our Galaxy atLband (856–1712 MHz) in all four StokesI,Q,U, andV. The image rms noise levels of 12–17μJy ba⁻¹represent a significant increase in sensitivity over past image-based pulsar searches. Our primary search criterion was circular polarization, but we used other criteria, including linear polarization, in-band spectral index, compactness, variability, and multiwavelength counterparts to select pulsar candidates. We first demonstrate the efficacy of this technique by searching for polarized emission from known pulsars and comparing our results with measurements from the literature. Our search resulted in a sample of 75 polarized sources. Bright stars or young stellar objects were associated with 28 of these sources, including a small sample of highly polarized dwarf stars with pulsar-like steep spectra. Comparing the properties of this sample with the known pulsars, we identified 30 compelling candidates for pulsation follow-up, including two sources with both strong circular and linear polarization. The remaining 17 sources are either pulsars or stars, but we cannot rule out an extragalactic origin or image artifacts among the brighter, flat-spectrum objects. 

ABSTRACT In this paper, we present an optimized version of the detection pipeline for the ASKAP Variables and Slow Transients (VAST) survey, offering significant performance improvement. The key to this optimization is the replacement of the original w-projection algorithm integrated in the Common Astronomy Software Applications package with the w-stacking algorithm implemented in the WSClean software. Our experiments demonstrate that this optimization improves the overall processing efficiency of the pipeline by approximately a factor of 3. Moreover, the residual images generated by the optimized pipeline exhibit lower noise levels and fewer artefact sources, suggesting that our optimized pipeline not only enhances detection accuracy but also improves imaging fidelity. This optimized VAST detection pipeline is integrated into the Data Activated Liu Graph Engine (DALiuGE) execution framework, specifically designed for SKA-scale big data processing. Experimental results show that the performance and scalability advantages of the pipeline using DALiuGE over traditional MPI or BASH techniques increase with the data size. In summary, the optimized transient detection pipeline significantly reduces runtime, increases operational efficiency, and decreases implementation costs, offering a practical optimization solution for other ASKAP imaging pipelines as well. 

ABSTRACT The population of radio-loud stars has to date been studied primarily through either targeted observations of a small number of highly active stars or wide-field, single-epoch surveys that cannot easily distinguish stellar emission from background extragalactic sources. As a result it has been difficult to constrain population statistics such as the surface density and fraction of the population producing radio emission in a particular variable or spectral class. In this paper, we present a sample of 36 radio stars detected in a circular polarization search of the multi-epoch Variables and Slow Transients (VAST) pilot survey with ASKAP at 887.5 MHz. Through repeat sampling of the VAST pilot survey footprint we find an upper limit to the duty cycle of M-dwarf radio bursts of $$8.5 \,\rm {per\,cent}$$, and that at least 10 ± 3 $$\rm {per\,cent}$$ of the population should produce radio bursts more luminous than $$10^{15} \,\rm {erg}\mathrm{s}^{-1} \,\mathrm{Hz}^{-1}$$. We infer a lower limit on the long-term surface density of such bursts in a shallow $$1.25 \,\mathrm{m}\rm {Jy}\rm\ {PSF}^{-1}$$ sensitivity survey of $${9}^{\, +{11}}_{-{7}}\times 10^{-3}$$  $$\,\deg ^{-2}$$ and an instantaneous radio star surface density of 1.7 ± 0.2 × 10−3  $$\,\deg ^{-2}$$ on 12 min time-scales. Based on these rates we anticipate ∼200 ± 50 new radio star detections per year over the full VAST survey and $${41\, 000}^{\, +{10\, 000}}_{-{9\, 000}}$$ in next-generation all-sky surveys with the Square Kilometre Array. 

Abstract We present an intensive multiwavelength monitoring campaign of the quasar PG 1302−102 with Swift and the Las Cumbres Observatory network telescopes. Atz∼ 0.3, it tests the limits of the reverberation mapping (RM) technique in probing the accretion disk around a supermassive black hole (SMBH) and extends the parameter space to high masses and high accretion rates. This is also the first time the RM technique has been applied to test disk structures predicted in the SMBH binary model that has been suggested for this source. PG 1302−102 was observed at a ∼daily cadence for ∼9 months in 14 bands spanning from X-ray to UV and optical wavelengths, and it shows moderate to significant levels of variability correlated between wavelengths. We measure the interband time lags, which are consistent with aτ∝λ^4/3relation as expected from standard disk reprocessing, albeit with large uncertainties. The disk size implied by the lag spectrum is consistent with the expected disk size for its black hole mass within uncertainties. While the source resembles other reverberation-mapped active galactic nuclei in many respects, and we do not find evidence supporting the prevalent hypothesis that it hosts an SMBH binary, we demonstrate the feasibility of studying SMBH binaries from this novel angle and suggest possibilities for the LSST Deep Drilling Fields. 

Abstract Although neutron star–black hole binaries have been identified through mergers detected in gravitational waves, a pulsar–black hole binary has yet to be detected. While short-period binaries are detectable due to a clear signal in the pulsar’s timing residuals, effects from a long-period binary could be masked by other timing effects, allowing them to go undetected. In particular, a long-period binary measured over a small subset of its orbital period could manifest via time derivatives of the spin frequency incompatible with isolated pulsar properties. We assess the possibility of pulsars having unknown companions in long-period binaries and put constraints on the range of binary properties that may remain undetected in current data, but that may be detectable with further observations. We find that for 35% of canonical pulsars with published higher-order derivatives, the precision of measurements is not enough to confidently reject binarity (period ≳2 kyr), and that a black hole binary companion could not be ruled out for a sample of pulsars without published constraints if the period is >1 kyr. While we find no convincing cases in the literature, we put more stringent limits on orbital period and longitude of periastron for the few pulsars with published higher-order frequency derivatives (n≥ 3). We discuss the detectability of candidates and find that a sample pulsar in a 100 yr orbit could be detectable within 5–10 yr. 

Abstract We present the Sydney Radio Star Catalogue, a new catalogue of stars detected at megahertz to gigahertz radio frequencies. It consists of 839 unique stars with 3 405 radio detections, more than doubling the previously known number of radio stars. We have included stars from large area searches for radio stars found using circular polarisation searches, cross-matching, variability searches, and proper motion searches as well as presenting hundreds of newly detected stars from our search of Australian SKA Pathfinder observations. The focus of this first version of the catalogue is on objects detected in surveys using SKA precursor and pathfinder instruments; however, we will expand this scope in future versions. The 839 objects in the Sydney Radio Star Catalogue are distributed across the whole sky and range from ultracool dwarfs to Wolf-Rayet stars. We demonstrate that the radio luminosities of cool dwarfs are lower than the radio luminosities of more evolved sub-giant and giant stars. We use X-ray detections of 530 radio stars by the eROSITA soft X-ray instrument onboard the Spectrum Roentgen Gamma spacecraft to show that almost all of the radio stars in the catalogue are over-luminous in the radio, indicating that the majority of stars at these radio frequencies are coherent radio emitters. The Sydney Radio Star Catalogue can be found in Vizier or athttps://radiostars.org.