COVID-19 patients exhibit differential disease severity after SARS-CoV-2 infection. It is currently unknown as to the correlation between the magnitude of neutralizing antibody (NAb) responses and ...the disease severity in COVID-19 patients. In a cohort of 59 recovered patients with disease severity including severe, moderate, mild, and asymptomatic, we observed the positive correlation between serum neutralizing capacity and disease severity, in particular, the highest NAb capacity in sera from the patients with severe disease, while a lack of ability of asymptomatic patients to mount competent NAbs. Furthermore, the compositions of NAb subtypes were also different between recovered patients with severe symptoms and with mild-to-moderate symptoms. These results reveal the tremendous heterogeneity of SARS-CoV-2-specific NAb responses and their correlations to disease severity, highlighting the needs of future vaccination in COVID-19 patients recovered from asymptomatic or mild illness.
Abstract We present a study of a sample of 45 spectroscopically confirmed, UV luminous galaxies at z ∼ 6. They were selected as bright Lyman-break galaxies (LBGs) using deep multiband optical images ...in more than 2 deg 2 of the sky, and subsequently identified via their strong Ly α emission. The majority of these LBGs span an absolute UV magnitude range from −22.0 to −20.5 mag with Ly α equivalent width (EW) between ∼10 and ∼200 Å, representing the most luminous galaxies at z ∼ 6 in terms of both UV continuum emission and Ly α line emission. We model the spectral energy distributions of 10 LBGs that have deep infrared observations from Hubble Space Telescope, JWST, and/or Spitzer, and find that they have a wide range of stellar masses and ages. They also have high star formation rates ranging from a few tens to a few hundreds of solar mass per year. Five of the LBGs have JWST or HST images, and four of them show compact morphology in these images, including one that is roughly consistent with a point source, suggesting that UV luminous galaxies at this redshift are generally compact. The fraction of our photometrically selected LBGs with strong Ly α emission (EW > 25 Å) is about 0.2, which is consistent with previous results and supports a moderate evolution of the intergalactic medium opacity at the end of cosmic reionization. Using deep X-ray images, we do not find evidence of strong active galactic nucleus (AGN) activity in these galaxies, but our constraint is loose, and we are not able to rule out the possibility of any weak AGN activity.
One-step hydrogenation of phenol is a preferable and economic route for preparing cyclohexanone. The development of catalysts with high catalytic performance and easy recovery still keeps a ...significant challenge. Herein, the novel ZIF-derived hierarchically porous carbon nanofibers (ZCNFs) were fabricated by electrospinning and calcination with ZIF-67 as the nanoparticles precursor and PAN as the CNFs precursor, and they were used as the supports of Pd nanoparticles for preparing the Pd@ZCNFs-x catalysts x is the mass ratio of ZIF-67 to PAN (%). Pd@ZCNFs-20 exhibits superior catalytic performance in the phenol hydrogenation to cyclohexanone, and its catalytic activity is 2.2 times higher than that of Pd@ZCNFs-0. The ZIF-67 doping is in favor of the formation of ZCNFs with more defects, larger surface area, hierarchical pore structure, higher N content and better Pd dispersion, thereby improving the catalytic activity. Furthermore, the as-prepared Pd@ZCNFs-20 catalyst is easy to be recovered from the reaction mixture due to its one-dimensional structure, and shows good reusability during six reaction cycles. In view of the high catalytic performance and reusability of the Pd@ZCNFs catalysts, the developed hybrid ZCNFs are potential candidates for the phenol hydrogenation.
Graphic Abstract
The ZIF-67 doping is in favor of the formation of ZIF-derived hierarchical porous carbon nanofibers (ZCNFs) with more defects, larger surface area, hierarchical pore structure, higher N content and better Pd dispersion, thereby improving the catalytic activity of Pd@ZCNFs in the phenol hydrogenation to cyclohexanone.
•The mock-up fabricated by hot isostatic pressing assisted brazing process successfully endured the cyclic absorbed heat flux at 20 MW m−2 for 1000 cycles.•The peak temperature of the tungsten (W) ...surface reached 926 °C at the 1000th cycle, which is less than the recrystallization temperature.•The mock-up was characterized by no detachment at the joints, no ‘hot spot’ and no w melting and detachment during the tests. Furthermore, defects exceeding Φ2 mm equivalent are absent from the W/Cu and Cu/CuCrZr interfaces of the mock-up after 1000 cycle HHF tests.•The flat-type W/Cu/CuCrZr structure is very promising to be used to upgrade the divertor of EAST and manufacture the divertor for CFETR.
Divertor is one of the most challenging plasma facing components (PFCs) for fusion reactors both from the design and fabrication technology point of view. In this work, the new flat-type W/Cu/CuCrZr mock-ups were fabricated using hot isostatic pressing (HIP) and optimized brazing techniques. High heat flux (HHF) tests of the mock-up were performed on a comprehensive experimental platform to assess the heat removal capability and thermal fatigue resistance. The results indicate that the mock-up successfully endured the cyclic absorbed heat flux at 20 MW m−2 for 1000 cycles with an inlet pressure of 1 MPa, an inlet water temperature of 20 °C and a velocity of 6.88 m s−1. The peak temperature of the tungsten (W) surface reached 926 °C at the 1000th cycle, which is less than the recrystallization temperature. In addition, no substantial melting at the loaded W surfaces, no detachment of any W/Cu units and no occurrence of any ‘hot spot’ during thermal fatigue cycling were observed. These results indicate that HIP assisted brazing technique is a powerful method for fabricating PFCs employed in HHF tests, and the flat-type W/Cu/CuCrZr structure is very promising to be used to upgrade the lower divertor of Experimental Advanced Superconducting Tokamak(EAST) and manufacture the divertor for China Fusion Engineering Test Reactor(CFETR).
Abstract The evolution of the quasar luminosity function (QLF) is fundamental to understanding the cosmic evolution of black holes (BHs) through their accretion phases. In the era of the James Webb ...Space Telescope (JWST), Euclid, and Nancy Grace Roman Space Telescope, their unprecedented detection sensitivity and wide survey area can unveil the low-luminosity quasar and low-mass BH population, and provide new insights into quasar host galaxies. We present a theoretical model describing BH growth from initial seeding at z ≳ 20 to ∼ 4, incorporating the duration of accretion episodes, the distribution of Eddington ratios, and the mass dependency of BH accretion rates. By constraining the model parameters with the observed QLFs at 4 ≤ z ≤ 6 across a wide UV luminosity range, we find that the high-redshift BH population grows rapidly at z ≳ 6, and decelerates the pace in subsequent epochs. Toward lower redshifts ( z < 6), mass-dependent accretion inhibits the growth of high-mass BHs with M • > 10 8 M ⊙ , leading to mass saturation at M • ≳ 10 10 M ⊙ . We predict the BH mass function down to M • ∼ 10 6 M ⊙ for both unobscured and obscured quasar populations at 4 ≤ z ≤ 11, offering a benchmark for future observational tests. Our model accounts for the presence of both bright and faint quasars at z > 4, including those discovered by JWST. Furthermore, our findings suggest two distinct pathways for the early assembly of the BH–galaxy mass correlation: the population with a BH-to-stellar-mass ratio near the local value of M • / M ⋆ ≃ 5 × 10 −3 maintains proximity to the relation via moderate growth, while the population that begins to grow above the local relation becomes as overmassive as M • / M ⋆ ∼ 0.01–0.1 by z ∼ 6 via rapid mass accretion.
•Speckles based on TaC powders and alcohol is robust and stable at ultra-high temperature.•Three experimental schemes are designed for different temperature ranges to suppress blackbody radiation at ...ultra-high temperature.•The full field strain of tungsten block is obtained from 250 to 3067 °C.
With the development of aerospace and fusion engineering, understanding the mechanical behavior of materials under high-temperature conditions has become increasingly important. However, few studies are devoted to the ultra-high temperature range of 2000–3000 °C. In this study, with the aim of developing non-contact measuring techniques of mechanical deformation under ultra-high temperature, a high heat flux (~300 MW) comprehensive experimental platform is established, which includes a vacuum chamber, a three-dimensional digital image correlation (3D-DIC) system, infrared radiation thermometers and an electron beam heating system. Using the electron beam heating technique, the tungsten specimen can be heated to over 3000 °C. Owing to the use of a vacuum chamber, the thermally induced airflow disturbance at high temperature can be completely removed. Tantalum carbide (TaC) powder is chosen as the speckle material and speckle fabrication technology is developed to adapt ultra-high temperatures under vacuum conditions. In order to suppress the blackbody radiation at high temperature, three schemes based on blue light sources, self-radiating light sources and a dual wavelength optical filter technique are designed for three temperature ranges from room temperature to 3067 °C. Afterwards, full-field thermal deformation of the tungsten specimen above 3000 °C was determined based on the above strategies using the 3D-DIC technique. The feasibility and accuracy of the proposed methods are verified by comparing the measurement results with the thermal expansion strain data and model from available databases and literature. The standard deviations in different temperature intervals are 50 με for 25–1200 °C, 100–200 με for 1200–1800 °C and less than 500 με for 1800–3067 °C. The proposed methods and technologies are expected to lay a foundation for further developments in strain field measurements at ultra-high temperature.
Flexible and hierarchical nanostructured Pd/SiO
2
-TiO
2
nanofibrous catalytic membranes were fabricated via combining electrospinning technique and a two-step hydrothermal method. The size and ...distribution of TiO
2
nanorods immobilised on SiO
2
nanofibrous membranes can be regulated via adjusting the dosage of TiCl
3
solution in the first step hydrothermal process. When using an optimal TiCl
3
solution dosage of 0.2 mL, a hierarchical structured Pd/SiO
2
-TiO
2
-0.2 nanofibrous catalytic membrane with uniformly dense TiO
2
nanorods loaded on SiO
2
nanofibers is obtained, and still shows good tensile strength and flexibility. The catalytic activity of Pd/SiO
2
-TiO
2
-0.2 increases 5 times as compared to Pd/SiO
2
-TiO
2
-0 in the reduction of p-nitrophenol (PNP) to p-aminophenol (PAP). The modification with TiO
2
nanorods can provide more surface areas for loading the Pd nanoparticles, thereby increased active sites. The three-dimensional open-cell network stacked and assembled by thousands of SiO
2
nanofibers and TiO
2
nanorods enhances the contact between the reactants and Pd nanoparticles. Both aspects contribute the superior catalytic activity of Pd/SiO
2
-TiO
2
-0.2. Furthermore, a continuous and complete conversion of PNP to PAP can be stably operated over 240 min in a gravity-driven catalytic membrane reactor constructed by Pd/SiO
2
-TiO
2
-0.2.
Prostate cancer (PCa) is one of the most common malignancies in men worldwide. This study was designed to investigate the potential of Ribosomal Protein L22-like1 (RPL22L1) and Ribosomal Protein S21 ...(RPS21) as diagnostic and prognostic biomarkers for PCa. First, RPL22L1 and RPS21 were screened as the key molecular of PCa by bioinformatics analysis. Subsequently, the prostate tissue samples were stained for antibodies against RPL22L1 and RPS21. The unbiased signal quantification was performed by ImageJ software, and the results showed that the expression of RPL22L1 and RPS21 exhibited significant differences between the PCa tissues and the normal prostate tissues. Receiver-operating characteristics (ROC) curves were prepared, and then the area under the curve (AUC) values of RPL22L1 and RPS21 were calculated as 0.798 and 0.768, and the likelihood ratio (LR) values of RPL22L1 and RPS21 were calculated as 2.86 and 2.53. These data implied that the over-expression of RPL22L1 and RPS21 is associated with the presence of PCa. The further analysis suggested that the expression of RPL22L1 and RPS21 were significantly higher in high Gleason grade than they were in low Gleason grade. In addition, in vitro studies were undertaken to evaluate the roles of RPL22L1 and RPS21 in PCa. The results revealed that these genes promote PCa cell proliferation, migration and invasion, and inhibit PCa cell apoptosis. Taken together, these data showed that RPL22L1 and RPS21 exhibited higher expression in human prostate cancer tissue, and involved in PCa cell proliferation and invasion. This research provided a novel insight into diagnostic and prognostic biomarkers for PCa.
Surface defect classification is one of key points in the field of steel manufacturing. It remains challenging primarily due to the rare occurrence of defect samples and the similarity between ...different defects. In this paper, a multi-level semantic method based on residual adversarial learning with Wasserstein divergence is proposed to realize sample augmentation and automatic classification of various defects simultaneously. Firstly, the residual module is introduced into model structure of adversarial learning to optimize the network structure and effectively improve the quality of samples generated by model. By substituting original classification layer with multiple convolution layers in the network framework, the feature extraction capability of model is further strengthened, enhancing the classification performance of model. Secondly, in order to better capture different semantic information, we design a multi-level semantic extractor to extract rich and diverse semantic features from real-world images to efficiently guide sample generation. In addition, the Wasserstein divergence is introduced into the loss function to effectively solve the problem of unstable network training. Finally, high-quality defect samples can be generated through adversarial learning, effectively expanding the limited training samples for defect classification. The experimental results substantiate that our proposed method can not only generate high-quality defect samples, but also accurately achieve the classification of defect detection samples.
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