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The uncertainty of measured cross sections is relatively large due to the higher energy of neutrons in fast neutron spectrum reactors and the smaller cross sections compared to the low-energy range. The uncertainty of these cross-sections affects the uncertainty of reactor physics calculations results. Previous research results show that nuclear data uncertainty is a major source of uncertainty in reactor physics calculations. However, the analysis of uncertainty requires software for processing nuclear cross section covariance data which are from the neutron Evaluated Nuclear Data File (ENDF), which heavily relies on relevant foreign computational software, such as NJOY. Currently, there are few reports on domestic software for processing nuclear data covariance data, and there is limited research on its methods and theories. Therefore, this study delves into the theory of multi-group covariance ENDF data processing method and develops the multi-group covariance processing module CovarXS within the independently developed advanced nuclear cross section (XS) processing program AXSP. A 33-group covariance database was generated based on the ENDF/B-Ⅶ.1 evaluated nuclear data file. To verify the correctness of the developed CovarXS module, relative covariance matrices for 238U(n,inel), 239Pu(n,fiss), and 56Fe(n,elas) were generated using the module based on the ENDF/B-Ⅶ.1 evaluated nuclear database. By comparing the results with the ERRORR module in NJOY2016, it is found that the maximum relative error of the computed covariance data between the two programs is within 1.0%. The relative errors for 238U(n,inel) and 239Pu(n,fiss) are less than 0.001%. The relative error for 56Fe(n,elas) is slightly larger, but still do not exceed 1%. Based on these results, the 33-group covariance matrices were used to analyze the BN-600 benchmark problem of a MOX-fueled sodium-cooled fast reactor. The nuclides and types of cross-sections that contributed the most uncertainty to the keff were identified. The calculation results show that the relative errors of the total keff uncertainty contributions from all nuclides obtained using the CovarXS module and the ERRORR module are less than 0.11%. The nuclide with the largest contribution is 238U, followed by 239Pu, 56Fe, 23Na, and others. For the 238U nuclide, the reaction channel contributing the most to keff is (n,inel), followed by the (n,g) reaction channel of 239Pu. The total relative uncertainty of keff caused by the main nuclides is 0.893%. This indicates that the precision of the multi-group covariance database generated by the CovarXS module is comparable to that generated by the ERRORR module. The relative covariance data generated using the CovarXS module can provide reliable data for subsequent uncertainty analysis.

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Nanoscale transport through nanopores and live-cell membranes plays a vital role in both key biological processes as well as biosensing and DNA sequencing. Active translocation of DNA through these nanopores usually needs enzyme assistance. Here we present a nanopore derived from truncated helicase E1 of bovine papillomavirus (BPV) with a lumen diameter of c.a. 1.3 nm. Cryogenic electron microscopy (cryo-EM) imaging and single channel recording confirm its insertion into planar lipid bilayer (BLM). The helicase nanopore in BLM allows the passive single-stranded DNA (ssDNA) transport and retains the helicase activity in vitro. Furthermore, we incorporate this helicase nanopore into the live cell membrane of HEK293T cells, and monitor the ssDNA delivery into the cell real-time at single molecule level. This type of nanopore is expected to provide an interesting tool to study the biophysics of biomotors in vitro, with potential applications in biosensing, drug delivery and real-time single cell analysis.

Background: The reported outcomes of pediatric dilated cardiomyopathy (DCM) have varied across studies. There are few outcome data concerning DCM in Chinese children. Therefore, we conducted a retrospective study to describe clinical features and determine risk factors for poor outcomes in children with DCM. Methods: We enrolled 121 children with DCM in our hospital from 2003 to 2021. General information and laboratory and echocardiographic data were collected and analyzed. Cox regression analysis was performed to determine risk factors for poor outcomes. Results: This study included 121 patients (69 males and 52 females). The median age at diagnosis was 10.8 years, and the follow-up time was 10.0 months. Eighty-two patients (67.8%) exhibited cardiac function classes III–IV at the time of diagnosis. Tachypnea was the most common symptom (78.5%). In echocardiography, the mean left ventricular end-diastolic dimension z score was 7.36 ± 2.73, and the left ventricular ejection fraction z score was −6.58 ± 2.17. The 1-, 2-, and 5-year survival rates were 51.2%, 43.8%, and 32.2%, respectively. Cox analysis revealed that cardiac function classes III–IV (hazard ratio [HR] = 1.801, 95% confidence interval [95% CI] = 1.030–3.149, p = 0.039) and calcium levels (HR = 0.219, 95% CI = 0.084–0.576, p = 0.002) were predictors of poor outcomes in children with DCM. Conclusions: Children with DCM are at high risk of death. Cardiac function class III–IV and calcium levels were related to the prognosis of pediatric DCM patients. [ABSTRACT FROM AUTHOR]

Potato starch can improve the 3D printability of surimi, but the molecular mechanism was not clear. The surimi from golden pompano was the research object and extracted myofibrillar protein from the surimi. The blend system was prepared with myofibrillar protein and potato starch and determined the rheological properties, microstructure, and intermolecular force. The 3D printing effect of surimi was evaluated. The fundamental reason why potato starch improved the 3D printability of surimi was analyzed. Results showed that the content of ionic bonds and hydrophobic interaction between protein molecules decreased, while the content of hydrogen bonds and disulfide covalent bonds increased, which promoted the conformational changes of amino acids in the side chain of protein molecules. When the mass ratio of myofibrillar protein to potato starch was 6:4, the link strength between rheological units of the blend system was 8 877. 2 Pa·s1 / z and the apparent viscosity was 2 818 Pa·s. At this time, the 3D printing effect of surimi was the best, and the printing accuracy and stability were 99. 6% and 98. 12% respectively. This study provided theoretical support for the formulation design and development of 3D-printed surimi products and had far-reaching practical significance for the wide application of 3D printing in the food industry. [ABSTRACT FROM AUTHOR]

Pediatric heart failure (HF) is associated with high readmission rates, but the optimal serum potassium range for this population remains unclear. In this single-center retrospective cohort study, 180 pediatric patients hospitalized for HF between January 2016 and January 2022 were stratified into low-potassium (<3.7 mmol/L), middle-potassium (3.7–4.7 mmol/L), and high-potassium (≥4.7 mmol/L) groups based on the distribution of potassium levels in the study population. The primary outcome was readmission for HF within 1 year of discharge. Cox regression and restricted cubic spline models were used to assess the association between potassium levels and 1-year HF readmission rates. Notably, 38.9% of patients underwent 1 or more 1-year readmissions for HF within 1 year. The high-potassium group had a significantly higher readmission frequency than the middle-potassium group. In multivariate Cox regression models, potassium levels of ≥4.7 mmol/L were independently associated with increased 1-year readmission risk. A J-shaped relationship was observed between baseline potassium levels and 1-year readmission risk, with the lowest risk at 4.1 mmol/L. In pediatric patients with HF, a serum potassium level ≥ 4.7 mmol/L was independently associated with increased 1-year readmission risk. Maintaining potassium levels within a narrow range may improve outcomes in this population. [ABSTRACT FROM AUTHOR]

Magnesium hydride (MgH2) has been recognized as a promising anode material of lithium‐ion batteries (LIBs) owing to its ultrahigh specific capacity. The low conductivity and the structural pulverization induced by large volume expansion, however, has long limited its practical lithium storage performance. Herein, a series of yolk‐shell‐like structures, composed of porous MgH2 nanoparticles (NPs) decorated with Mg‐based composites through in‐situ solid‐gas reaction using MgH2 as both the reactant and the structural template, have been fabricated and uniformly dispersed on electronically conductive graphene. It could not only physically accommodate the volume change of MgH2 owing to the physical protection of Mg‐based composites and the formation of void space inside MgH2 NPs, but also effectively facilitate the transportation of electrons throughout the whole electrode. Particularly, the uniform decoration of ultrathin Mg(BH4)2 as the shell with thermodynamically favorable intercalation of lithium ions and low kinetic barrier for the lithium‐ion diffusion promotes facile transportation of lithium ions into active MgH2, which, coupled with the porous structure constructed by flexible graphene, effectively improves the ion conductivity of the electrode. The synergistic improvement in electronic and ionic conductivity leads to a high reversible capacity of 1651 mAh g−1 at 200 mA g−1 after 380 cycles. [ABSTRACT FROM AUTHOR]

Cultural relics line graphic serves as a crucial form of traditional artifact information documentation, which is a simple and intuitive product with low cost of displaying compared with 3D models. Dimensionality reduction is undoubtedly necessary for line drawings. However, most existing methods for artifact drawing rely on the principles of orthographic projection that always cannot avoid angle occlusion and data overlapping while the surface of cultural relics is complex. Therefore, conformal mapping was introduced as a dimensionality reduction way to compensate for the limitation of orthographic projection. Based on the given criteria for assessing surface complexity, this paper proposed a three-dimensional feature guideline extraction method for complex cultural relic surfaces. A 2D and 3D combined factor that measured the importance of points on describing surface features, vertex weight, was designed. Then the selection threshold for feature guideline extraction was determined based on the differences between vertex weight and shape index distributions. The feasibility and stability were verified through experiments conducted on real cultural relic surface data. Results demonstrated the ability of the method to address the challenges associated with the automatic generation of line drawings for complex surfaces. The extraction method and the obtained results will be useful for line graphic drawing, displaying and propaganda of cultural relics. [ABSTRACT FROM AUTHOR]