The deep dielectric charging effects monitor (DDCEM) that measures the surface leakage currents and the internal charging potentials of the dielectric is equipped on a Chinese medium Earth orbit ...(MEO) navigation satellite to monitor deep dielectric charging risk in real time and research deep dielectric charging effects onboard. In this article, we focus on the largest observed charging event and take it as an example to discuss the possible applications of the DDCEM data. As expected, the location of the peak currents and potential values are between 4.4 and 7.7 L-shells. Smaller L-shells mean larger currents and potential variations. Some lag effect (~minutes) is observed due to the dielectric charging time constant. Further analysis shows that DDCEM can be used as an onboard conductivity measuring apparatus or an onboard charging electric field monitor. The calculated flame retardant 4 (FR4) dielectric top surface's conductivity <inline-formula> <tex-math notation="LaTeX">\sigma _{\mathrm {top}} </tex-math></inline-formula> (<inline-formula> <tex-math notation="LaTeX">9.1\times 10^{-14} - 1.5\times 10^{-13} </tex-math></inline-formula> S/m) and the bottom surface's conductivity <inline-formula> <tex-math notation="LaTeX">\sigma _{\mathrm {bottom}} </tex-math></inline-formula> (<inline-formula> <tex-math notation="LaTeX">1.1\times 10^{-14} - 3.4\times 10^{-14} </tex-math></inline-formula> S/m) are much larger than the conductivity (<inline-formula> <tex-math notation="LaTeX"> < 2.5\times 10^{-15} </tex-math></inline-formula> S/m) in National Aeronautics and Space Administration (NASA)-HDBK-4002A. The calculated peak charging electric field near the FR4 dielectric top surface (<inline-formula> <tex-math notation="LaTeX">2.6\times 10^{3} - 1.2\times 10^{4} </tex-math></inline-formula> V/m) and bottom surface (<inline-formula> <tex-math notation="LaTeX">5.5\times 10^{3} - 3.1\times 10^{4} </tex-math></inline-formula> V/m) is much less than the risk value 106 V/m, which is from the European Space Agency (ESA) final report, meaning that there was no charging risk during the period of this study.
The humidity field of shotcrete with an alkali-free or alkaline accelerator was measured under sealed or drying conditions. The pore structures of the cement paste were characterized, and the ...influence of the accelerators on water-transmission characteristics and humidity change in the shotcrete was identified. The results show that the use of an accelerator increases the water loss rate under drying conditions, resulting in a lower internal humidity and a higher humidity gradient in shotcrete. The alkaline accelerator has a greater impact on the internal moisture of the shotcrete than the alkali-free accelerator, as the accelerator reacts with cement particles to produce a large number of rod-shape hydration products (Ettringite), resulting in the increase of pore size and cumulative porosity in cement, and the effect is stronger for the longer age (28 d) samples. The diffusion coefficient of shotcrete with an accelerator was determined and found to be significantly higher than that of the control group. The diffusion coefficient with an alkaline accelerator was slightly higher than the sample with an alkali-free accelerator. The calculated humidity was in a good agreement with the experimental data.
Photocatalysis is one of the most promising pathways to relieve the environmental contamination caused by the rapid development of modern technology. In this work, we demonstrate a green ...manufacturing process for the 3D/3D rod-shaped bamboo charcoal/Bi2WO6 photocatalyst (210BC-BWO) by controlled carbonization temperature. A series of morphology characterization and properties investigations (XRD, SEM, UV–vis DRS, transient photocurrent response, N2 absorption-desorption isotherms) indicate a 210BC-BWO photocatalyst with higher charge separation efficiency, larger surface area, and better adsorption capacity. The excellent photocatalytic performance was evaluated by degrading rhodamine B (RhB) (98.5%), tetracycline hydrochloride (TC-HCl) (77.1%), and H2 evolution (2833 μmol·g−1·h−1) coupled with furfuryl alcohol oxidation (3097 μmol·g−1·h−1) under visible light irradiation. In addition, the possible mechanisms for degradation of organic pollutants, H2 evolution, and furfuryl alcohol oxidation were schematically investigated, which make it possible to exert photocatalysis by increasing the active radical. This study shows that the combination of bamboo charcoal and bismuth tungstate can be a powerful photocatalyst that rationally combines H2 evolution coupled with furfuryl alcohol oxidation and degradation of pollutants.
Despite the ubiquitous mechanical cues at both spatial and temporal dimensions, cell identities and functions are largely immune to the everchanging mechanical stimuli. To understand the molecular ...basis of this epigenetic stability, we interrogated compressive force-elicited transcriptomic changes in mesenchymal stem cells purified from human periodontal ligament (PDLSCs), and identified H3K27me3 and E2F signatures populated within upregulated and weakly downregulated genes, respectively. Consistently, expressions of several E2F family transcription factors and EZH2, as core methyltransferase for H3K27me3, decreased in response to mechanical stress, which were attributed to force-induced redistribution of RB from nucleoplasm to lamina. Importantly, although epigenomic analysis on H3K27me3 landscape only demonstrated correlating changes at one group of mechanoresponsive genes, we observed a genome-wide destabilization of super-enhancers along with aberrant EZH2 retention. These super-enhancers were tightly bounded by H3K27me3 domain on one side and exhibited attenuating H3K27ac deposition and flattening H3K27ac peaks along with compensated EZH2 expression after force exposure, analogous to increased H3K27ac entropy or decreased H3K27ac polarization. Interference of force-induced EZH2 reduction could drive actin filaments dependent spatial overlap between EZH2 and super-enhancers and functionally compromise the multipotency of PDLSC following mechanical stress. These findings together unveil a specific contribution of EZH2 reduction for the maintenance of super-enhancer stability and cell identity in mechanoresponse.
The time-dependent autogenous shrinkage of shotcrete under different alkali content and dosage of accelerators was tested. The adiabatic temperature rise, microstructure, chemical compound, and ...mercury injection test were characterized to determine the influence of accelerators on the autogenous shrinkage of shotcrete. The previous theoretical model for shrinkage was improved by introducing the influence factor of expansive hydration products. An autogenous shrinkage prediction model suitable for shotcrete was proposed, and the relevant model parameters were calibrated based on experimental results. Compared with the control group, alkali-free or alkaline accelerator significantly accelerates the autogenous shrinkage of shotcrete, which is mainly due to the accelerating effect on the hydration process at an early age and the free water absorption in the hydration process; Compared with the alkaline accelerator, alkali-free accelerator generates a large amount of expansive hydration product Ettringite. Therefore the autogenous shrinkage of shotcrete with alkali-free accelerator was smaller than that with alkaline accelerator. By introducing the influence factor
p
1
the previous shrinkage model was improved. The new model can better describe the influence of expansive hydration products generated by accelerators on the shrinkage of shotcrete. The theoretical model is suitable to investigate the shrinkage development of the initial tunnel support structures.
Despite the emerging evidence on ferroptosis implicated in diverse pathologies, molecular linkage between oxidative inducers and chromatin as epigenetic memory carrier for its propagation remains ...elusive. Here, we report the identification of two WD40 proteins DCAF8 and WDR76 as substrate adapter and molecular inhibitor respectively of the Cullin-4 RING ubiquitin ligase (CRL4) system for stability control of chromatin remodeler LSH. Degradation analysis and CRL4-DCAF8 complex reconstitution demonstrate that CRL4DCAF8 is a bona fide E3 ligase for LSH. In contrast, WDR76 antagonizes DCAF8-targeted LSH proteolysis through competitive inhibition of the holo-CRL4DCAF8-LSH complex assembly. Importantly, this opposing regulatory strategy is utilized in lipid hydroperoxide induced ferroptosis, where we identify key redox homeostasis genes significantly regulated by the DCAF8/WDR76/LSH axis through transcriptomic epistasis analysis. This regulation is mechanistically attributed to DNA hydroxymethylation fostered WDR76 interaction with LSH and increased ratio of DCAF8 to WDR76 for antagonistic LSH association accompanying decreased DNA oxidation along with ROS overproduction. Evaluation of epigenetic dynamics at ferroptosis gene promoters reveals linker histone H1- and LSH-associated transcriptional repression is coordinately removed upon lipid peroxidation stress. Together with the phenotypes driven by WDR76 and DCAF8 manipulations, these data identify DCAF8- and WDR76-adapted oxidative damage sensing through DNA hydroxymethylation for LSH degradation control as a crucial nexus in epigenetic regulation of ferroptosis.
Objectives:
Premature coronary artery disease (PCAD) is increasingly common in Asian countries; however, less is known regarding its characteristics and clinical outcomes. This study aims to describe ...clinical characteristics and investigate clinical outcomes in real-world Asian patients with PCAD.
Methods:
A total of 4700 Asian patients undergoing drug-eluting stent implantation were included in our study and divided into PCAD group and mature CAD (MCAD) group according to their onset age. All patients were followed up for 3 years to observe their clinical outcomes.
Results:
Patients with PCAD were more likely to be associated with acute coronary syndrome (ACS; P = .03) and acute occlusive lesion (P < .001). Reference diameter (P < .001) and lesion diameter stenosis (P = .001) were significantly greater in PCAD group. Conversely, the MCAD group was more likely to be associated with left main disease, severe calcification lesion and small vessel involvement. The cumulative incidences of major adverse cardiovascular event (MACE; P = .007), cardiovascular death (P < .001), and all cause death (P < .001) were significantly lower in PCAD group than those in MCAD group.
Conclusions:
Although more often manifested as ACS, PCAD is associated with lower risks of MACE and cardiovascular death than MCAD in real-world Asian population.
Coronary angiography (CAG) as a typical imaging modality for the diagnosis of coronary diseases hasbeen widely employed in clinical practices. For CAG-based computer-aided diagnosis systems, accurate ...vessel segmentation plays a fundamental role. However, patients with bradycardia usually have a pacemaker which frequently interferes the vessel segmentation. In this case, the segmentation of vessels will be hard. To mitigate interferences of pacemakers and then extract main vessels more effectively in CAG images, we propose an approach. At first, a pseudo CAG (pCAG) image is generated through a part of a CAG sequence, in which the pacemaker exists. Then, a local feature descriptor is employed to register the relative location of pacemaker between the pCAG image and the target CAG image. Finally, combining the registration result and segmentation results of main vessels and pacemaker, interferences of pacemaker are removed and the segmentation of main vessels is improved. The proposed method is evaluated based o
This study proposes a novel AC vector magnetometer developed using a low-resource magneto-impedance sensor for China’s Feng-Yun meteorological satellite (FY-3E). It was calibrated and characterized ...to determine its performance parameters. The total weight of the AC vector magnetometer is 51 g (the aluminum box excluded), while the total power consumption is 310 mW. The proposed AC vector magnetometer can detect magnetic field variations in the range of ±1000 nT and noise power spectral density of ⩽ 50 pT/Hz
1/2
@ 1 Hz. Furthermore, the proposed device has a maximum nonlinearity of ⩽ 0.71‰ over the entire range and a nonorthogonality error of 3.07 nT or 0.15% (root mean square). The total dose hardness of the sensor is ⩾ 30 krad (Si). Furthermore, we propose the first survey results of a magnetometer equipped aboard a Chinese FY-3E satellite in a Sun-synchronous orbit. The data revealed that the AC vector magnetometer can detect transient physical signals such as quasistatic field-aligned currents (~50 nT) and waves at the auroral latitudes. These features render the proposed AC vector magnetometer suitable for space-based applications, particularly those involving the study of geomagnetic activity.
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