10 research outputs found
K-doped Ba122 epitaxial thin film on MgO substrate by buffer engineering
Molecular beam epitaxy of K-doped Ba122
(BaKFeAs) superconductor was realized on a
MgO substrate. Microstructural observation revealed that the undoped Ba122
served as a perfect buffer layer for epitaxial growth of the K-doped Ba122. The
film exhibited a high critical temperature of 39.8 K and a high critical
current density of 3.9 MA/cm at 4 K. The successful growth of
epitaxial thin film will enable artificial single grain boundary on oxide
bicrystal substrates and reveal the grain boundary transport nature of K-doped
Ba122.Comment: 5 pages, 4 figures, accepted manuscript Supercond. Sci. Technol 202
Self-similar finite-time blowups with smooth profiles of the generalized Constantin-Lax-Majda model
We show that the -parameterized family of the generalized
Constantin-Lax-Majda model, also known as the Okamoto-Sakajo-Wensch model,
admits exact self-similar finite-time blowup solutions with interiorly smooth
profiles for all . Depending on the value of , these self-similar
profiles are either smooth on the whole real line or compactly supported and
smooth in the interior of their closed supports. The existence of these
profiles is proved in a consistent way by considering the fixed-point problem
of an -dependent nonlinear map, based on which detailed characterizations of
their regularity, monotonicity, and far-field decay rates are established. Our
work unifies existing results for some discrete values of and also explains
previous numerical observations for a wide range of .Comment: 44 pages, 8 figure
Multi-Scale Analysis of the Relationship between Land Subsidence and Buildings: A Case Study in an Eastern Beijing Urban Area Using the PS-InSAR Technique
Beijing is severely affected by land subsidence, and rapid urbanisation and building construction might accelerate the land subsidence process. Based on 39 Envisat Advanced Synthetic Aperture Radar (ASAR) images acquired between 2003–2010, 55 TerraSAR-X images acquired between 2010–2016, and urban building information, we analysed the relationship between land subsidence and buildings at the regional, block, and building scales. The results show that the surface displacement rate in the Beijing urban area ranged from −109 mm/year to +13 mm/year between 2003–2010, and from −151 mm/year to +19 mm/year between 2010–2016; two subsidence bowls were mainly distributed in the eastern part of the Chaoyang District. The displacement rate agreed well with the levelling measurements, with an average bias of less than six mm/year. At the regional scale, the spatial pattern of land subsidence was mainly controlled by groundwater extraction, compressible layer thickness, and geological faults. Subsidence centres were located in the area around ground water funnels with a compressible layer depth of 50–70 m. The block-scale analysis demonstrated a clear correlation between the block construction age and the spatial unevenness of subsidence. The blocks constructed between 1998–2005 and after 2005 showed considerably more subsidence unevenness and temporal instability than the blocks constructed before 1998 during both time periods. The examination of the new blocks showed that the spatial unevenness increased with building volume variability. For the 16 blocks with a high building volume, variability, and subsidence unevenness, the building-scale analysis showed a positive relationship between building volume and settlement in most blocks, although the R2 was lower than 0.5. The results indicate that intense building construction in urban areas could cause differential settlement at the block scale in Beijing, while the settlement of single buildings could be influenced by the integrated effects of building volume, foundation structures, and the hydrogeological background
A modified temperature integral approximation formula and its application in pyrolysis kinetic parameters of waste tire
<p>A modified temperature integral approximation formula was proposed to calculate the kinetic parameters of tire pyrolysis. The relative error percentage of our formula was less than 0.02% at the range of 5 ≤ <i>u</i> ≤ 80. In order to validate our formula, the kinetic parameters of waste tire pyrolysis in a Thermogravimetric Analyzer (TG) were calculated according to different temperature integral approximation formula. The results demonstrated that the coefficient of the experimental TG and simulated TG from our formula was higher than that from Coats-Redfern method. The active energies of tire pyrolysis were 33.03 (120–300°C), 72.30 (300–420°C), and 50.83 kJ/mol (420–500°C).</p
Circulating DNA methylation level of CXCR5 correlates with inflammation in patients with rheumatoid arthritis
Abstract Objectives To assess the differences in circulating DNA methylation levels of CXCR5 between rheumatoid arthritis (RA) and osteoarthritis (OA) and healthy controls (HC), and the correlation of methylation changes with clinical characteristics of RA patients. Methods Peripheral blood samples were collected from 239 RA patients, 30 patients with OA, and 29 HC. Target region methylation sequencing to the promoter region of CXCR5 was achieved using MethylTarget. The methylation level of cg04537602 and methylation haplotype were compared among the three groups, and the correlation between methylation levels and clinical characteristics of RA patients was performed by Spearman's rank correlation analysis. Results The methylation level of cg04537602 was significantly higher in the peripheral blood of RA patients compared with OA patients (p = 1.3 × 10−3) and in the HC group (p = 5.5 × 10−4). The sensitivity was enhanced when CXCR5 methylation level combined with rheumatoid factor and anti–cyclic citrullinated peptide with area under curve (AUC) of 0.982 (95% confidence interval 0.970–0.995). The methylation level of cg04537602 in RA was positively correlated with C‐reactive protein (CRP) (r = .16, p = .01), and in RA patients aged 60 years and above, cg04537602 methylation levels were positively correlated with CRP (r = .31, p = 4.7 × 10−4), tender joint count (r = .21, p = .02), visual analog scales score (r = .21, p = .02), Disease Activity Score in 28 joints (DAS28) using the CRP level DAS28‐CRP (r = .27, p = 2.1 × 10−3), and DAS28‐ESR (r = .22, p = .01). We also observed significant differences of DNA methylation haplotypes in RA patients compared with OA patients and HC, which was consistent with single‐loci‐based CpG methylation measurement. Conclusion The methylation level of CXCR5 was significantly higher in RA patients than in OA and HC, and correlated with the level of inflammation in RA patients, our study establishes a link between CXCR5 DNA methylation and clinical features that may help in the diagnosis and disease management of RA patients
Targeted demethylation of the CDO1 promoter based on CRISPR system inhibits the malignant potential of breast cancer cells
Abstract Background Cysteine dioxygenase 1 (CDO1) is frequently methylated, and its expression is decreased in many human cancers including breast cancer (BC). However, the functional and mechanistic aspects of CDO1 inactivation in BC are poorly understood, and the diagnostic significance of serum CDO1 methylation remains unclear. Methods We performed bioinformatics analysis of publicly available databases and employed MassARRAY EpiTYPER methylation sequencing technology to identify differentially methylated sites in the CDO1 promoter of BC tissues compared to normal adjacent tissues (NATs). Subsequently, we developed a MethyLight assay using specific primers and probes for these CpG sites to detect the percentage of methylated reference (PMR) of the CDO1 promoter. Furthermore, both LentiCRISPR/dCas9‐Tet1CD‐based CDO1‐targeted demethylation system and CDO1 overexpression strategy were utilized to detect the function and underlying mechanism of CDO1 in BC. Finally, the early diagnostic value of CDO1 as a methylation biomarker in BC serum was evaluated. Results CDO1 promoter was hypermethylated in BC tissues, which was related to poor prognosis (p < .05). The CRISPR/dCas9‐based targeted demethylation system significantly reduced the PMR of CDO1 promotor and increased CDO1 expression in BC cells. Consequently, this leads to suppression of cell proliferation, migration and invasion. Additionally, we found that CDO1 exerted a tumour suppressor effect by inhibiting the cell cycle, promoting cell apoptosis and ferroptosis. Furthermore, we employed the MethyLight to detect CDO1 PMR in BC serum, and we discovered that serum CDO1 methylation was an effective non‐invasive biomarker for early diagnosis of BC. Conclusions CDO1 is hypermethylated and acts as a tumour suppressor gene in BC. Epigenetic editing of abnormal CDO1 methylation could have a crucial role in the clinical treatment and prognosis of BC. Additionally, serum CDO1 methylation holds promise as a valuable biomarker for the early diagnosis and management of BC