Extreme mass ratio inspirals (EMRIs) are important sources for space-borne gravitational wave detectors, such as the laser interferometer space antenna and TianQin. Previous EMRI rate studies have ...focused on the "loss cone" scenario, where stellar-mass black holes (sBHs) are scattered into highly eccentric orbits near the central massive black hole (MBH) via multibody interaction. In this work, we calculate the rate of EMRIs of an alternative formation channel: EMRI formation assisted by the accretion flow around accreting massive black holes. In this scenario, sBHs and stars on inclined orbits are captured by the accretion disk, and then subsequently migrate towards the MBH, under the influence of density wave generation and head wind. By solving the Fokker-Planck equation incorporating both sBH-sBH–sBH-star scatterings and sBH–star-disk interactions, we find that an accretion disk usually boosts the EMRI formation rate per individual MBH by O ( 101 – 103 ) compared with the canonical loss cone formation channel. Taking into account that the fraction of active Galactic nuclei (AGNs) is ∼ O ( 10−2 − 10−1), where the MBHs are expected to be rapidly accreting, we expect EMRI formation assisted by AGN disks to be an important channel for all EMRIs observed by space-borne gravitational wave detectors. These two channels also predict distinct distributions of EMRI eccentricities and orbit inclinations with respect to the MBH spin equatorial plane, which can be tested by future gravitational wave observations.
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We show that gravitational floating orbits may exist for black holes with rotating hairs. These black hole hairs could originate from the superradiant growth of a light axion field around the ...rotating black holes. If a test particle rotates around the black hole, its tidal field may resonantly trigger the dynamical transition between a corotating state and a dissipative state of the axion cloud. A tidal bulge is generated by the beating of modes, which feeds angular momentum back to the test particle. Following this mechanism, an extreme-mass-ratio-inspiral (EMRI) system, as a source for LISA, may face delayed merger as the EMRI orbit stalls by the tidal response of the cloud, until the cloud is almost fully dissipated. If the cloud depletes slower than the average time separation between EMRI mergers, it may lead to interesting interaction between multiple EMRI objects at comparable radii. Inclined EMRIs are also expected to migrate towards the black hole equatorial plane due to the tidal coupling and gravitational-wave dissipation. Floating stellar-mass back holes or stars around the nearby intermediate-mass black holes may generate strong gravitational-wave emission detectable by LISA.
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High mobility group box 1 (HMGB1) is a highly conserved, nuclear protein present in all cell types. It is a multi-facet protein exerting functions both inside and outside of cells. Extracellular ...HMGB1 has been extensively studied for its prototypical alarmin functions activating innate immunity, after being actively released from cells or passively released upon cell death. TLR4 and RAGE operate as the main HMGB1 receptors. Disulfide HMGB1 activates the TLR4 complex by binding to MD-2. The binding site is separate from that of LPS and it is now feasible to specifically interrupt HMGB1/TLR4 activation without compromising protective LPS/TLR4-dependent functions. Another important therapeutic strategy is established on the administration of HMGB1 antagonists precluding RAGE-mediated endocytosis of HMGB1 and HMGB1-bound molecules capable of activating intracellular cognate receptors. Here we summarize the role of HMGB1 in inflammation, with a focus on recent findings on its mission as a damage-associated molecular pattern molecule and as a therapeutic target in inflammatory diseases. Recently generated HMGB1-specific inhibitors for treatment of inflammatory conditions are discussed.
•γ-Ray irradiation is a very suitable method for the formation of hydrogels without cross-linking agent.•We consider mixing chitosan into gelatin/PVA hydrogels to optimize the hydrogels mechanical ...properties.•The CTS/Gel/PVA hydrogels have excellent hemostatic properties.
Chitosan (CS)/gelatin (Gel)/polyvinyl alcohol (PVA) hydrogels were prepared by the gamma irradiation method for usage in wound dressing applications. Chitosan and gelatin solution was mixed with poly(vinyl alcohol) (PVA) solution at different weight ratios of CS/Gel of 1:3, 1:2, 1:1, 2:1 and 3:1. The hydrogels irradiated at 40kGy. The structure of the hydrogels was characterized by using FT-IR and SEM. The CS/Gel/PVA hydrogels were characterized for physical properties and blood clotting activity. The tensile strength of CS/Gel/PVA hydrogel enhanced than on the basis of the Gel/PVA hydrogel. The highest tensile strength reached the 2.2Mpa. All hydrogels have shown a good coagulation effect. It takes only 5min for the BCI index to reached 0.032 only 5min when the weight ratio of CS/Gel was 1:1. It means that the hemostatic effect of hydrogels were optimal. And the hydrogrls also showed good pH-sensitivity, swelling ability and water evaporation rate. Therefore, this hydrogel showed a promising potential to be applied as wound dressing.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
We study on image super-resolution (SR), which aims to recover realistic textures from a low-resolution (LR) image. Recent progress has been made by taking high-resolution images as references (Ref), ...so that relevant textures can be transferred to LR images. However, existing SR approaches neglect to use attention mechanisms to transfer high-resolution (HR) textures from Ref images, which limits these approaches in challenging cases. In this paper, we propose a novel Texture Transformer Network for Image Super-Resolution (TTSR), in which the LR and Ref images are formulated as queries and keys in a transformer, respectively. TTSR consists of four closely-related modules optimized for image generation tasks, including a learnable texture extractor by DNN, a relevance embedding module, a hard-attention module for texture transfer, and a soft-attention module for texture synthesis. Such a design encourages joint feature learning across LR and Ref images, in which deep feature correspondences can be discovered by attention, and thus accurate texture features can be transferred. The proposed texture transformer can be further stacked in a cross-scale way, which enables texture recovery from different levels (e.g., from 1x to 4x magnification). Extensive experiments show that TTSR achieves significant improvements over state-of-the-art approaches on both quantitative and qualitative evaluations.
Summary
Ribosome biogenesis is a highly dynamic and orchestrated process facilitated by hundreds of ribosomal biogenesis factors and small nucleolar RNAs. While many of the advances are derived from ...studies in yeast, ribosome biogenesis remains largely unknown in plants despite its importance to plant growth and development.
Through characterizing the maize (Zea mays) defective kernel and embryo‐lethal mutant dek58, we show that DEK58 encodes an Rrp15p domain‐containing protein with 15.3% identity to yeast Rrp15. Over‐expression of DEK58 rescues the mutant phenotype.
DEK58 is localized in the nucleolus. Ribosome profiling and RNA gel blot analyses show that the absence of DEK58 reduces ribosome assembly and impedes pre‐rRNA processing, accompanied by the accumulation of nearly all the pre‐rRNA processing intermediates and the production of an aberrant processing product P‐25S*. DEK58 interacts with ZmSSF1, a maize homolog of the yeast Ssf1 in the 60S processome. DEK58 and ZmSSF1 interact with ZmCK2α, a putative component of the yeast UTP‐C complex involved in the small ribosomal subunit processome.
These results demonstrate that DEK58 is essential to seed development in maize. It functions in the early stage of pre‐rRNA processing in ribosome biogenesis, possibly through interacting with ZmSSF1 and ZmCK2α in maize.
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Fuel cells are an incredibly powerful renewable energy technology, but their broad applications remains lagging because of the high cost and poor reliability of cathodic electrocatalysts for the ...oxygen reduction reaction (ORR). This review focuses on the recent progress of ORR electrocatalysts in fuel cells. More importantly, it highlights the fundamental problems associated with the insufficient activity translation from rotating disk electrode to membrane electrode assembly in the fuel cells. Finally, for the atomic‐level in‐depth information on ORR catalysts in fuel cells, potential perspectives are suggested, including large‐scale preparation, unified assessment criteria, advanced interpretation techniques, advanced simulation and artificial intelligence. This review aims to provide valuable insights into the fundamental science and technical engineering for efficient ORR electrocatalysts in fuel cells.
Fuel cells are a powerful renewable energy technology. This review gives a comprehensive overview on oxygen reduction electrocatalysts towards practical fuel cells.
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Abstract
Accretion disks of active galactic nuclei (AGNs) have been proposed as promising sites for producing both (stellar-mass) compact object mergers and extreme mass ratio inspirals. Along with ...disk-assisted migration, ambient gas inevitably accretes onto compact objects. In previous studies, it was commonly assumed that either an Eddington rate or a Bondi rate takes place, although they can differ by several orders of magnitude. As a result, the mass and spin evolution of compact objects within AGN disks are essentially unknown. In this work, we construct a relativistic supercritical inflow–outflow model for black hole (BH) accretion. We show that the radiation efficiency of the supercritical accretion of a stellar-mass BH (sBH) is generally too low to explain the proposed electromagnetic counterpart of GW 190521. Applying this model to sBHs embedded in AGN disks, we find that, although the gas inflow rates at Bondi radii of these sBHs are commonly highly super-Eddington, a large fraction of inflowing gas eventually escapes as outflows so that only a small fraction accretes onto the sBH, resulting in mildly super-Eddington BH absorption in most cases. We also apply this model to neutron stars (NSs) and white dwarfs (WDs) in AGN disks. It turns out to be difficult for WDs to grow to the Chandrasekhar limit via accretion because WDs are spun up more efficiently to reach the shedding limit before the Chandrasekhar limit. For NSs accretion-induced collapse is possible if NS magnetic fields are sufficiently strong to keep the NS slowly rotating during accretion.
In the environment of increasing pace of globalization and informatization, the distributed internet has effectively mobilized people from all countries to participate in the discussion of Marxist ...theory, which makes Marxist theory enriched in a decentralized, multi-node manner for the first time under the wave of globalization. Although the modern emerging distributed internet is faster and more rapid than the traditional information media methods, its accuracy is subject to a greater impact. In this paper, we collect the information of text-video web pages through a crawler program, and after filtering through artificial intelligence retrieval technology to obtain the Marxist globalization theory and extract key information points, and delete irrelevant information. Then K-means clustering algorithm is used to cluster the information collected in the distributed internet to obtain the multidimensional interpretation of Marxist’s globalization theory. This method has been proved to be effective through a large number of experiments. The existing distributed internet has a large amount of data that can be used to train artificial intelligence and has good practical conditions. This method helps Marxists to make better use of information from multiple nodes. The theoretical perspectives of working people from various countries are constantly gathered and pushed forward while saving a lot of manpower, so that Marxism can be better adapted to the rapidly developing globalized society.
Epidemiological evidence on the relationship between serum iron and liver diseases is limited. This study aims to investigate whether serum iron is associated with nonalcoholic fatty liver disease ...(NAFLD) and advanced hepatic fibrosis (AHF). Cross-sectional data for adults aged ≥ 18 years who participated in the National Health and Nutrition Examination Survey (NHANES) from 1999 to 2018 were analyzed. Odds ratio (ORs) and 95% confidence intervals (CIs) of NAFLD and AHF associated with serum iron were estimated using multivariable logistic regression models. A total of 18,031 males and 18,989 females were included in the analysis. After multivariable adjustment for potential confounders, serum iron was significantly and inversely associated with NAFLD in both genders (P-trend < 0.001) and AHF in females (P-trend = 0.018). Compared to the bottom quartile, those in higher quartiles of serum iron had no significant ORs for AHF in males, but the trend across the quartiles was significant (P-trend = 0.046). In conclusion, higher serum iron level was associated with lower risk of NAFLD in males and females, and with lower risk of AHF in females but not in males. No significant racial/ethnical differences in these associations were observed.
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