Effect of Multi-Path Asynchronous Rolling Process on Microstructure and Mechanical Properties of ZK60 Magnesium Alloy.

At the initial rolling temperature of 400 °C, ZK60 magnesium alloy was hot rolled by three different rolling paths with different roll speed ratios (RSR) of 1:1.15, 1:1.2, and 1:1.5, respectively. The effects of different rolling processes on the microstructure and mechanical properties of the alloy were studied. The microstructure, plasticity, strength, hardness, and texture intensity of rolled samples were analyzed in this work. The results show that the microstructure uniformity of the alloy under multi-path asynchronous rolling (MAR) is significantly improved, which improves the mechanical properties of the material to a certain extent, and effectively weakens the texture intensity of the basal plane and reduces the anisotropy. The amount of randomly oriented grains of ZK60 magnesium alloy rolled by the C-1.5 (path C combined with the RSR of 1:1.5) process are significantly increased, which significantly weakens the basal texture and improves the ductility of the alloy, greatly enhancing the processing and formability of ZK60 magnesium alloy.

Impact of rGO modified with FAS on corrosion protection performance of inorganic phosphate bonded coating.

In this paper, inorganic phosphate bonded coatings (IPBCs) via embedding reduced graphene oxide (rGO) modified with heptadecafluoro-1,1,2,2-tetradecyl trimethoxysilane (FAS) were prepared through sol-gel method. Aim of this paper is to research the corrosion resistance of IPBCs with the addition of rGO modified with FAS. Firstly, the Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy (Raman) and surface morphology of GO and rGO modified with and without FAS were characterized. Results indicated that the hydrophobic -CF2- and -CF3 groups were successfully introduced into GO and rGO after modification. And IPBCs with rGO-FAS exhibited higher hydrophobicity and corrosion resistance than IPBCs with the addition of GO or GO-FAS. That is because the hydrophobicity and the introduction of low surface energy material is conducive to overcoming the interaction of rGO itself, thus rGO can be better utilized and played, which resulting the excellent corrosion performance of IPBC@rGO-FAS.

3D Hollow Hierarchical Porous Carbon with Fe-N4 -OH Single-Atom Sites for High-Performance Zn-Air Batteries.

The development of innovative and efficient Fe-N-C catalysts is crucial for the widespread application of zinc-air batteries (ZABs), where the inherent oxygen reduction reaction (ORR) activity of Fe single-atom sites needs to be optimized to meet the practical application. Herein, a three-dimensional (3D) hollow hierarchical porous electrocatalyst (ZIF8@FePMPDA-920) rich in asymmetric Fe-N4 -OH moieties as the single atomic sites is reported. The Fe center is in a penta-coordinated geometry with four N atoms and one O atom to form Fe-N4 -OH configuration. Compared to conventional Fe-N4 configuration, this unique structure can weaken the adsorption of intermediates by reducing the electron density of the Fe center for oxygen binding, which decreases the energy barrier of the rate-determining steps (RDS) to accelerate the ORR and oxygen evolution reaction (OER) processes for ZABs. The rechargeable liquid ZABs (LZABs) equipped with ZIF8@FePMPDA-920 display a high power density of 123.11 mW cm-2 and a long cycle life (300 h). The relevant flexible all-solid-state ZABs (FASSZABs) also display outstanding foldability and cyclical stability. This work provides a new perspective for the structural design of single-atom catalysts in the energy conversion and storage areas.

Ambient air pollutants in the first trimester of pregnancy and birth defects: an observational study.

OBJECTIVES: As current studies on the relationships between air pollutants exposure during the first trimester and birth defects were not fully elucidated, this study aimed to assess the association between selected air pollutants and birth defects. DESIGN: An observational study. PARTICIPANTS: We obtained 70 854 singletons with gestational age <20 weeks who were delivered at a large maternal and child healthcare centre in Wuhan, China. OUTCOME MEASURES: Birth defects data and daily average concentration of ambient particulate matter ≤10 µm diameter (PM10), PM ≤2.5 µm diameter (PM2.5), sulfur dioxide (SO2) and nitrogen dioxide (NO2) were obtained. Logistic regression analysis was applied to assess the association between maternal air pollutants exposure during first trimester and total birth defects, congenital heart defects (CHDs), limb defects and orofacial clefts with adjustments of potential covariates. RESULTS: There were a total of 1352 birth defect cases included in this study, with a prevalence of 19.08‰. Maternal exposed to high concentrations of PM10, PM2.5, NO2 and SO2 in the first trimester were significantly associated with elevated ORs of birth defects (ORs ranged from 1.13 to 1.23). Additionally, for male fetuses, maternal exposed to high PM2.5 concentration was associated with an elevated odd of CHDs (OR 1.27, 95% CI 1.06 to 1.52). In the cold season, the ORs of birth defects were significantly increased among women exposed to PM2.5 (OR 1.64, 95% CI 1.41 to 1.91), NO2 (OR 1.22, 95% CI 1.08 to 1.38) and SO2 (OR 1.26, 95% CI 1.07 to 1.47). CONCLUSIONS: This study showed unfavourable effects of air pollutants exposure during the first trimester on birth defects. Especially, the association between maternal PM2.5 exposure and CHDs was only observed among male fetuses, and stronger effects of PM2.5, NO2 and SO2 exposure on birth defects were observed in the cold season.

The Application of DNA Ploidy Analysis in Large-Scale Population Screening for Cervical Cancer.

OBJECTIVE: The objective of this study was to evaluate the application of DNA ploidy analysis in large-scale population screening for cervical cancer. METHODS: From March 2016 to March 2019, eligible subjects were enrolled and recommended to undergo DNA ploidy analysis, the ThinPrep cytology test (TCT), and high-risk human papillomavirus (hrHPV) detection concurrently. Patients with positive results were recommended for colposcopy, and biopsy diagnosis was regarded as the "gold standard." We compared the test efficiencies of the 3 methods and compared the efficiency and accuracy of the TCT in our hospital and the "2-cancer screening" project in Hubei Province during the same period. RESULTS: Among 20,574 women, the positive rates of DNA ploidy analysis, cytology, and hrHPV testing were 4.01%, 4.71%, and 16.28%, respectively. The sensitivities of these methods for screening for grade 2+ cervical intraepithelial neoplasia were 0.70, 0.68, and 0.96, and their specificities were 0.79, 0.82, and 0.45, respectively. On comparing DNA ploidy analysis with the TCT, there was no significant difference in the sensitivity, specificity, positive predictive value, negative predictive value, and missed diagnosis rate. In opportunistic screening and the 2-cancer screening project, the positive rates of cytology were 4.71% and 2.87%, respectively. And the efficiency and accuracy of the TCT in opportunistic screening were higher than in the 2-cancer screening project. CONCLUSION: Therefore, DNA ploidy analysis, which is of low-cost and does not depend on cytopathologists, can replace cytology and be applied in large-scale population screening for cervical cancer.

Time trends and risk factor associated with premature birth and infants deaths due to prematurity in Hubei Province, China from 2001 to 2012.

BACKGROUND: The nutrition and epidemiologic transition has been associated with an increasing incidence of preterm birth in developing countries, but data from large observational studies in China have been limited. Our study was to describe the trends and factors associated with the incidence of preterm birth and infant mortality due to prematurity in Hubei Province, China. METHODS: We conducted a population-based survey through the Maternal and Child Health Care Network in Hubei Province from January 2001 to December 2012. We used data from 16 monitoring sites to examine the trend and risk factors for premature birth as well as infant mortality associated with prematurity. RESULTS: A total of 818,481 live births were documented, including 76,923 preterm infants (94 preterm infants per 1,000 live births) and 2,248 deaths due to prematurity (2.75 preterm deaths per 1,000 live births). From 2001 to 2012, the incidence of preterm birth increased from 56.7 to 105.2 per 1,000 live births (P for trend < 0.05), while the infant mortality rate due to prematurity declined from 95.0 to 13.4 per 1,000 live births (P for trend < 0.05). Older maternal age, lower maternal education, use of assisted reproductive technology (ART), higher income, residence in urban areas, and infant male sex were independently associated with a higher incidence of preterm birth (all p values < 0.05). Shorter gestation, lower birth weight, and lower income were associated with a higher mortality rate, while use of newborn emergency transport services (NETS) was associated with a lower preterm mortality rate (all p values < 0.05). CONCLUSION: An increasing incidence of preterm birth and a parallel reduction in infant mortality due to prematurity were observed in Hubei Province from 2001 to 2012. Our results provide important information for areas of improvements in reducing incidence and mortality of premature birth.

Thermally assisted electric field control of magnetism in flexible multiferroic heterostructures.

Thermal and electrical control of magnetic anisotropy were investigated in flexible Fe81Ga19 (FeGa)/Polyvinylidene fluoride (PVDF) multiferroic heterostructures. Due to the large anisotropic thermal deformation of PVDF (α1 = -13 × 10(-6) K(-1) and α2 = -145 × 10(-6) K(-1)), the in-plane uniaxial magnetic anisotropy (UMA) of FeGa can be reoriented 90° by changing the temperature across 295 K where the films are magnetically isotropic. Thus, the magnetization of FeGa can be reversed by the thermal cycling between 280 and 320 K under a constant magnetic field lower than coercivity. Moreover, under the assistance of thermal deformation with slightly heating the samples to the critical temperature, the electric field of ± 267 kV cm(-1) can well align the UMA along the two orthogonal directions. The new route of combining thermal and electrical control of magnetic properties realized in PVDF-based flexible multiferroic materials shows good prospects in application of flexible thermal spintronic devices and flexible microwave magnetic materials.