Most ultraluminous X-ray sources (ULXs) are thought to be supercritical accreting compact objects, where massive outflows are inevitable. Using the long-term monitoring data with the Swift X-ray ...Telescope, we identified a common feature in bright, hard ULXs: they display a quasi-periodic modulation in their hard X-ray band but not in their soft band. As a result, some sources show a bimodal distribution on the hardness intensity map. We argue that these model-independent results can be well interpreted in a picture that involves supercritical accretion with precession, where the hard X-ray emission from the central funnel is more or less beamed, while the soft X-rays may arise from the photosphere of the massive outflow and be nearly isotropic. It implies that precession may be ubiquitous in supercritical systems, such as the Galactic microquasar SS 433. How the hard X-rays are modulated can be used to constrain the angular distribution of the hard X-ray emission and the geometry of the accretion flow. We also find that two ULX pulsars (NGC 5907 ULX-1 and NGC 7793 P13) show similar behaviors but no bimodal distribution, which may imply that they have a different beaming shape or mechanism.
We report human endophthalmitis caused by pseudorabies virus infection after exposure to sewage on a hog farm in China. High-throughput sequencing and real-time PCR of vitreous humor showed ...pseudorabies virus sequences. This case showed that pseudorabies virus might infect humans after direct contact with contaminants.
Nanobody (Nb) is a promising vector for targeted drug delivery. This study aims to identify an Nb that can specifically target the lung by binding human pulmonary surfactant protein A (SP-A). Human ...lung frozen tissue sections were used for 3 rounds of biospanning of our previously constructed Nb library for rat SP-A to establish a sub-library of Nb, which specifically bound human lung tissues. Phage-ELISA was performed to screen the sub-library to identify Nb4, which specifically bound human SP-A. The binding affinity Kd of Nb4 to recombinant human SP-A was 7.48 × 10
M. Nb4 (19 kDa) was stable at 30 °C-37 °C and pH 7.0-7.6 and specifically bound the SP-A in human lung tissue homogenates, human lung A549 cells, and human lung tissues, whereas didn't react with human liver L-02 cells, kidney 293T cells, and human tissues from organs other than the lung. Nb4 accumulated in the lung of nude mice 5 minutes after a tail vein injection of Nb4 and was excreted 3 hours. Short-term exposure (one month) to Nb4 didn't cause apparent liver and kidney toxicity in rats, whereas 3-month exposure resulted in mild liver and kidney injuries. Nb4 may be a promising vector to specifically deliver drugs to the lung.
This study aims to use high throughput 16SrRNA gene sequencing to examine the bacterial profile of lymph node biopsy samples of patients with sarcoidosis and to further verify the association between ...Propionibacterium acnes (P. acnes) and sarcoidosis.
A total of 36 mediastinal lymph node biopsy specimens were collected from 17 cases of sarcoidosis, 8 tuberculosis (TB group), and 11 non-infectious lung diseases (control group). The V4 region of the bacterial 16SrRNA gene in the specimens was amplified and sequenced using the high throughput sequencing platform MiSeq, and bacterial profile was established. The data analysis software QIIME and Metastats were used to compare bacterial relative abundance in the three patient groups.
Overall, 545 genera were identified; 38 showed significantly lower and 29 had significantly higher relative abundance in the sarcoidosis group than in the TB and control groups (P < 0.01). P. acnes 16SrRNA was exclusively found in all the 17 samples of the sarcoidosis group, whereas was not detected in the TB and control groups. The relative abundance of P. acnes in the sarcoidosis group (0.16% ± 0. 11%) was significantly higher than that in the TB (Metastats analysis: P = 0.0010, q = 0.0044) and control groups (Metastats analysis: P = 0.0010, q = 0.0038). The relative abundance of P. granulosum was only 0.0022% ± 0. 0044% in the sarcoidosis group. P. granulosum 16SrRNA was not detected in the other two groups.
High throughput 16SrRNA gene sequencing appears to be a useful tool to investigate the bacterial profile of sarcoidosis specimens. The results suggest that P. acnes may be involved in sarcoidosis development.
Abstract
Accretion is an essential physical process in black hole X-ray binaries (BHXRBs) and active galactic nuclei. The properties of accretion flows and their radiation were originally considered ...to be uniquely determined by the mass accretion rate of the disk; however, the “hysteresis effect” observed during outbursts of nearly all BHXRBs seriously challenges this paradigm. The hysteresis effect referred to is that the hard-to-soft state transition in the fast-rise stage occurs at much higher luminosity than the soft-to-hard state transition in the slow-decay stage. That is, the same source can show different spectral/temporal properties at the same luminosity. Phenomenologically, this effect is also represented as the so-called “q”-shaped hardness-intensity diagram, which has been proposed as a unified scene for BHXRBs. However, there is still a lack of quantitative theoretical interpretation and observational understanding of the “q”-diagram. Here, we present a detailed time-lag analysis of a recently found BHXRB, MAXI J1348-630, intensively monitored by
Insight
-HXMT over a broad energy band (1–150 keV). We find the first observational evidence that the observed time-lag between radiations of the accretion disk and the corona leads naturally to the hysteresis effect and the “q”-diagram. Moreover, complemented by the quasi-simultaneous Swift data, we achieve a panorama of the accretion flow: the hard X-ray outburst from the corona heats and subsequently induces the optical brightening in the outer disk with nearly no lag; thereafter, the enhanced accretion in the outer disk propagates inward, generating the delayed soft X-ray outburst at the viscous timescale of ∼8–12 days.
The Be X-ray pulsar SMC X-3 underwent a giant outburst from 2016 August to 2017 March, which was monitored with the Swift satellite. During the outburst, its broadband flux increased dramatically, ...and the unabsorbed X-ray luminosity reached an extreme value of erg s−1 around August 24. Using the Swift/XRT data, we measured the observed pulse frequency of the neutron star to compute the orbital parameters of the binary system. After applying the orbital corrections to Swift observations, we found that the spin frequency increased steadily from 128.02 mHz on August 10 and approached the spin equilibrium of ∼128.74 mHz in 2017 January with an unabsorbed luminosity of erg s−1, indicating a strong dipolar magnetic field of G at the neutron star surface. The spin-up rate is tightly correlated with its X-ray luminosity during the super-Eddington outburst. The pulse profile in the Swift/XRT data is variable, showing double peaks at the early stage of outburst and then merging into a single peak at low luminosity. Additionally, we report that a low-temperature ( keV) thermal component emerges in the phase-averaged spectra as the flux decays, and it may be produced from the outer truncated disk or the boundary layer between the exterior flow and the magnetosphere.
Both Alzheimer's disease (AD) and osteoporosis (OP) are common age‐associated degenerative diseases and are strongly correlated with clinical epidemiology. However, there is a lack of clear ...pathological relationship between the brain and bone in the current understanding. Here, it is found that young osteocyte, the most abundant cells in bone, secretes extracellular vesicles (OCYYoung‐EVs) to ameliorate cognitive impairment and the pathogenesis of AD in APP/PS1 mice and model cells. These benefits of OCYYoung‐EVs are diminished in aged osteocyte‐derived EVs (OCYAged‐EVs). Based on the self‐constructed OCY‐EVs tracer transgenic mouse models and the in vivo fluorescent imaging system, OCY‐EVs have been observed to be transported to the brain under physiological and pathological conditions. In the hippocampal administration of Aβ40 induced young AD model mice, the intramedullary injection of Rab27a‐shRNA adenovirus inhibits OCYYoung‐EVs secretion from bone and aggravates cognitive impairment. Proteomic quantitative analysis reveals that OCYYoung‐EVs, compared to OCYAged‐EVs, enrich multiple protective factors of AD pathway. The study uncovers the role of OCY‐EV as a regulator of brain health, suggesting a novel mechanism in bone‐brain communication.
It is found that the osteocyte‐derived extracellular vesicles (OCY‐EVs) isolated from young osteocytes can ameliorate cognitive impairment and pathogenies of AD, but not OCY‐EVs isolated from aged osteocytes. OCY‐EV can transfer to the brain under physiological and pathological conditions. The study uncovers the role of OCY‐EVs as a regulator of brain, suggesting a novel mechanism in bone‐brain communication.
Cancer stem-like cells/cancer-initiating cells (CSCs/CICs) are considered to represent a small population of cancer cells that is resistant to conventional cancer treatments and responsible for tumor ...recurrence and metastasis. The aim of this study was to establish CSC/CIC-targeting immunotherapy. In this study, we found that Annexin A3 (ANXA3) was preferentially expressed in CSCs/CICs derived from hepatocellular carcinoma (HCC) cells compared to non-CSCs/CICs. In HCC samples, high levels of ANXA3 correlated with expansion of CD133(+) tumor cells representing CSCs/CICs in HCC; the combination of high levels of ANXA3 and CD133 was associated with progression of HCC. Overexpression of ANXA3 increased the proportion of CD133(+) cells, enhancing their tumorigenicity. On the contrary, knockdown of ANXA3 decreased CD133(+) cells and inhibited tumorigenicity. The mechanistic study revealed that ANXA3-mediated maintenance of HCC CSCs/CICs activity was likely involved with the HIF1A/Notch pathway. Using ANXA3 as a target, ANXA3-transfected dendritic cells could induce more functionally active T cells and these effector T cells could superiorly kill CD133(+) HCC CSCs/CICs in vitro and in vivo. Taken together, our findings suggest that ANXA3 plays a role in HCC CSC/CIC maintenance, and that ANXA3 may represent a potential CSC/CIC-specific therapeutic target for improving the treatment of HCC.
Abstract
We present a deep optical imaging campaign on the starburst galaxy NGC 4631 with CFHT/MegaCam. By supplementing the HST/ACS and Chandra/ACIS archival data, we search for the optical ...counterpart candidates of the five brightest X-ray sources in this galaxy, four of which are identified as ultraluminous X-ray sources (ULXs). The stellar environments of the X-ray sources are analyzed using the extinction-corrected color–magnitude diagrams and the isochrone models. We discover a highly asymmetric bubble nebula around X4 that exhibits different morphology in the H
α
and O
iii
images. The O
iii
/H
α
ratio map shows that the H
α
-bright bubble may be formed mainly via the shock ionization by the one-sided jet/outflow, while the more compact O
iii
structure is photoionized by the ULX. We constrain the bubble expansion velocity and interstellar medium density with the MAPPINGS V code and hence estimate the mechanical power injected into the bubble as
P
w
∼ 5 × 10
40
erg s
−1
and the corresponding bubble age as ∼7 × 10
5
yr. Relativistic jets are needed to provide such a level of mechanical power with a mass-loss rate of ∼10
−7
M
⊙
yr
−1
. Besides the accretion, the black hole spin is likely an additional energy source for the super-Eddington jet power.
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