Explore the vast range of titles available.

The Lobster Eye Imager for Astronomy (LEIA) detected a new X-ray transient on 2022 November 7, identified as a superflare event occurring on a nearby K-type giant star HD 251108. The flux increase was also detected in follow-up observations at X-ray, UV, and optical wavelengths. The flare lasted for about 40 days in soft X-ray observations, reaching a peak luminosity of ∼1.1 × 1034 erg s−1 in 0.5–4.0 keV, which is roughly 60 times the quiescent luminosity. Optical brightening was observed for only one night. The X-ray light curve is well described by a double fast rise and exponential decay model, attributed to the cooling process of a loop arcade structure formed subsequent to the initial large loop with a half-length of ∼1.9 × 1012 cm. Time-resolved X-ray spectra were fitted by a four-temperature apec model (with three components being the quiescent background), showing significant evolution of plasma temperature and emission measure over time. The estimated energy released in the LEIA band is ∼3 × 1039 erg, suggesting that this is likely the most energetic X-ray stellar flare with the longest duration detected to date.

A new species, Primula lizipingensis W.B.Ju, L.Y.He & X.F.Gao, found in Shimian County, Sichuan, China, is described and illustrated. It is morphologically similar to P. rhodochroa and P. socialis , but can be distinguished from them in having shorter plants covering with white farinose, leaf margin sharply dentate above the middle, the leaf blade becomes papery after drying, scapes obsolete, the bract linear-lanceolate to subulate, solitary at the base of the pedicel, and the white hairs present inside the corolla tube.

A dozen X-ray supernova shock breakout (SN SBO) candidates were reported recently based on XMM-Newton archival data, which increased the X-ray-selected SN SBO sample by an order of magnitude. Assuming that they are genuine SN SBOs, we study the luminosity function (LF) by improving on the method used in our previous work. The light curves and the spectra of the candidates were used to derive the maximum volume within which these objects could be detected with XMM-Newton by simulation. The results show that the SN SBO LF can be described by either a broken power law (BPL) with indices (at the 68% confidence level) of 0.48 ± 0.28 and 2.11 ± 1.27 before and after the break luminosity at log(Lb/ergs−1) = 45.32 ± 0.55 or a single power law (SPL) with an index of 0.80 ± 0.16. The local event rate densities of SN SBOs above 5 × 1042 erg s−1 are consistent for two models, i.e., 4.6−1.3+1.7×104 Gpc−3 yr−1 and 4.9−1.4+1.9×104 Gpc−3 yr−1 for BPL and SPL models, respectively. The number of fast X-ray transients of SN SBO origin can be significantly increased by wide-field X-ray telescopes such as the Einstein Probe.

Release of individuals is an effective conservation approach to protect endangered species. To save this small isolated giant panda population in Liziping Nature Reserve, a few giant pandas have been released to this population. Here we assess genetic diversity and future changes in the population using noninvasive genetic sampling after releasing giant pandas. In this study, a total of 28 giant pandas (including 4 released individuals) were identified in the Liziping, China. Compared with other giant panda populations, this population has medium-level genetic diversity; however, a Bayesian-coalescent method clearly detected, quantified, and dated a recent decrease in population size. The predictions for genetic diversity and survival of the population in the next 100 years indicate that this population has a high risk of extinction. We show that released giant pandas can preserve genetic diversity and improve the probability of survival in this small isolated giant panda population. To promote the recovery of this population, we suggest that panda release should be continued and this population will need to release 10 males and 20 females in the future.

Background Although DHFR gene amplification has long been known as a major mechanism for methotrexate (MTX) resistance in cancer, the early changes and detailed development of the resistance are not yet fully understood. Methods We performed genomic, transcriptional and proteomic analyses of human colon cancer cells with sequentially increasing levels of MTX-resistance. Results The genomic amplification evolved in three phases (pre-amplification, homogenously staining region (HSR) and extrachromosomal DNA (ecDNA)). We confirm that genomic amplification and increased expression of DHFR , with formation of HSRs and especially ecDNAs, is the major driver of resistance. However, DHFR did not play a detectable role in the early phase. In the late phase (ecDNA), increase in FAM151B protein level may also have an important role by decreasing sensitivity to MTX. In addition, although MSH3 and ZFYVE16 may be subject to different posttranscriptional regulations and therefore protein expressions are decreased in ecDNA stages compared to HSR stages, they still play important roles in MTX resistance. Conclusion The study provides a detailed evolutionary trajectory of MTX-resistance and identifies new targets, especially ecDNAs, which could help to prevent drug resistance. It also presents a proof-of-principal approach which could be applied to other cancer drug resistance studies.

Background Sex differences in the clinical characteristics of cluster headache (CH) remain controversial in both Eastern and Western studies, and such differences have not been thoroughly investigated among Chinese patients. Methods This large-scale, multicenter cohort study included 1,206 patients from 31 provinces across China diagnosed with CH between May 2021 and December 2024, and was conducted within the framework of the Chinese Cluster Headache Register Individual Study. Demographic and clinical data were systematically collected from each participant using an electronic structured questionnaire, and compared all variables between sexes. Results In total, 1,206 patients were enrolled, with a female-to-male ratio of 1:3.94. Demographic analysis revealed that female patients had an earlier mean age of onset, higher educational attainment, and fewer unhealthy lifestyle factors compared to male patients. Female patients were also more likely to have comorbidities such as migraine (28.28% vs. 15.90%, P  < 0.001) and psychological conditions, including anxiety and depression, and to use oral rizatriptan for acute treatment (27.78% vs. 15.80%, P  < 0.001). With respect to cranial autonomic symptoms (CASs), female patients experienced eyelid edema (18.85% vs. 12.47%, P  = 0.010) and ptosis (56.97% vs. 49.90%, P  = 0.048) more frequently, and reported migraine-associated symptoms more often. Conversely, male patients more commonly presented with conjunctival hyperemia (56.03% vs. 38.52%, P  < 0.001), rhinorrhea (47.92% vs. 38.93%, P  = 0.012), and facial sweating (38.15% vs. 30.74%, P  = 0.032). Female patients had significantly higher frequencies of attacks during the early morning hours (2:00–8:00), whereas male patients experienced significantly more attacks during midday (10:00–14:00) and evening (16:00–20:00). Conclusion This study provides the first comprehensive analysis of multidimensional sex differences in Chinese patients with CH, encompassing social characteristics, clinical phenotypes, psychological burden, and circadian attack distribution. These findings offer valuable evidence for developing precision medicine approaches and sex-specific clinical management strategies for CH.

A bulk polymerization monomer dehydro- abietic acid-(2-acryloyloxy-ethoxy)-ethyl ester (DHA-DG-AC) was synthesized from dehydroabietic acid (DHA). The chemical structure of DHA-DG-AC was characterized by 1H NMR, 13C NMR, MS and FT-IR. The kinetics of the bulk polymerization of DHA-DG-AC was investigated by Differential Scanning Calorimeter (DSC). Two kinds of kinetic model (nth-order model and autocatalytic model) were used to investigate the polymerization process. The results showed that the experimental DSC curves were consistent with the computational data generated by the autocatalytic kinetic model, and the value of Ea was 95.73 kJ·mol−1.

RX J0134.2-4258 is one of the most super-Eddington narrow-line Seyfert 1 (NLS1) galaxies, on which we conducted a monitoring campaign from radio to X-rays. In this paper, we present a detailed analysis of its optical/UV spectra and broadband spectral energy distribution (SED). Our study shows that the preferred black hole mass of RX J0134.2-4258 is \\(M_{\\rm BH} \\sim 2 \\times 10^{7}~M_{\\odot}\\), giving a mass accretion rate through the outer disc of \\(\\dot{m}_{\\rm out} \\sim 20\\) (assuming zero spin), compared to the observed luminosity ratio \\(L_{\\rm bol}/L_{\\rm Edd} \\sim 6\\). This reduction in radiative efficiency is expected for super-Eddington flows, as power can be lost via advection and/or disc winds. We find that the optical/UV lines of RX J0134.2-4258 resemble those from weak-like quasars (WLQs), as it has notably weak C IV and N V emission lines. It also has drastic X-ray variability, again similar to that recently observed in some other WLQs. However, WLQs have systematically higher masses (\\(\\gtrsim 10^8~M_{\\odot}\\)), and lower Eddington ratios (\\(\\dot{m}_{\\rm out} \\sim 1\\)) than RX J0134.2-4258. We compare instead to the most extreme NLS1s, with similarly large \\(\\dot{m}_{\\rm out}\\) but smaller masses. These show similarly large reductions in radiative efficiency but their UV lines are not similarly wind-dominated. We suggest a new category of weak-line Seyfert (WLS) galaxies to describe sources like RX J0134.2-4258, and interpret its (so far unique) properties in a model, where the lower-disc-temperature in the higher-mass black holes leads to the UV-line-driving mechanism, which enhances the super-Eddington radiation-pressure-driven wind.

The liquidus and solidus temperatures of FeCrAl stainless steel were determined by differential scanning calorimetry（DSC） at different heating rates. They were also calculated by Thermo-calc software and empirical formulae separately. The accuracy of calculation results was assessed by comparison with the corresponding DSC results. The liquidus temperatures calculated by empirical formulae, which exhibited a maximum deviation of 8.6℃ were more accurate than those calculated using Thermo-calc, which exhibited a maximum deviation of 12.11℃. On the basis of Thermo-calc calculations performed under the Scheil model, the solidus temperature could be well determined from solid fraction（fS） vs. temperature（t） curves at fS = 0.99. Furthermore, a theoretical analysis to determine the solidus temperature with this method was also provided.

Extragalactic fast X-ray transients (eFXTs) represent a rapidly growing class of high-energy phenomena, whose physical origins remain poorly understood. With its wide-field, sensitive all-sky monitoring, the Einstein Probe (EP) has greatly increased the discovery rate of eFXTs. The search and identification of the optical counterparts of eFXT are vital for understanding their classification and constraining their physical origin. Yet, a considerable fraction of eFXTs still lack secure classifications due to the absence of timely follow-up observations. We carry out a systematic search of publicly available optical survey data and transient databases (including the Zwicky Transient Facility, ZTF, and the Transient Name Server, TNS) for optical counterparts to eFXT candidates detected by EP. In this paper, we describe our ongoing program and report the first results. Specifically, we identified the eFXT EP240506a to be associated with a UV/optical counterpart, AT 2024ofs. Spectroscopy of its host galaxy with VLT yields a redshift of \\(z = 0.120 \\pm 0.002\\). By combining archival survey data with early-time multiwavelength observations, we find that the luminosity and light-curve evolution of AT~2024ofs are consistent with a core-collapse supernova origin. From detectability simulations, we estimate a local event rate density \\(\\rho_{0}=8.8^{+21.2}_{-3.9}\\ \\mathrm{yr^{-1}\\, Gpc^{-3}}\\) for EP240506a-like events, and completeness-corrected rate of about \\(36\\)--\\(78\\ \\mathrm{yr^{-1}\\ Gpc^{-3}}\\) for EP-detected X-ray transients associated with supernovae. Our results demonstrate the potential of EP to uncover prompt high-energy emission from core-collapse supernovae and underscore the critical importance of timely follow-up of future eFXT events.