Microwave-Assisted Rational Designed CNT-Mn3 O4 /CoWO4 Hybrid Nanocomposites for High Performance Battery-Supercapacitor Hybrid Device.

Extensive research interest in hybrid battery-supercapacitor (BSH) devices have led to the development of cathode materials with excellent comprehensive electrochemical properties. In this work, carbon nanotube (CNT)-Mn3 O4 /CoWO4 triple-segment hybrid electrode is synthesized by using a two-step microwave-assisted hydrothermal route. Systematic physical characterization revealed that, with the assistance of microwave, granular Mn3 O4 and spheroid-like CoWO4 with preferred orientation, and oxygen vacancies are stacked or arranged on CNTs skeletons to construct a rational designed hybrid nanocomposite with abundant heterointerfaces and interfacial chemical bonds. Electrochemical evaluations show that the synergistic cooperation in CNT-Mn3 O4 /CoWO4 resulted in an ultra-high specific capacity (1907.5 C g-1 /529.8 mA h g-1 at 1 A g-1 ), a wide operating voltage window (1.15 V), the satisfactory rate capability (capacity maintained at 1016.5 C g-1 /282.3 mA h g-1 at 15 A g-1 ), and excellent cycling stability (117.2% initial capacity retention after 13000 cycles at 15 A g-1 ). In addition, the assembled CNT-Mn3 O4 /CoWO4 //N doped porous carbon (NC) BSH device delivered a stable working voltage of 2.05 V and superior energy density of 67.5 Wh kg-1 at power density of 1025 W kg-1 , as well as excellent stability (92.2% capacity retained at 5 A g-1 for 12600 cycles). This work provides a new and feasible tactic to develop high-performance transition metal oxide-based cathodes for advanced BSH devices.

Using dopamine interlayers to construct Fe/Fe3C@FeNC microspheres of high N-content for bifunctional oxygen electrocatalysts of Zn-air batteries.

High activity bifunctional oxygen electrocatalysts are crucial for the development of high performing Zn-air batteries. Fe-N-C systems decorated with Fe/Fe3C nanoparticles have been identified as prospective candidates in which almost all the active sites need the presence of N. To anchor more N, an Fe2O3 microsphere template was covered by a thin layer of polymerized dopamine (PDA) before it was mixed with a high N-content source of g-C3N4. The PDA interlayer not only provides a part of C and N but also serves as a buffer agent to hinder fast reactions between Fe2O3 and g-C3N4 during pyrolysis to avoid the destruction of the microsphere template. The prepared Fe/Fe3C@FeNC catalyst showed superior electrochemical performance, achieving a high half-wave potential of 0.825 V for ORR and a low overpotential of 1.450 V at 10 mA cm-2 for OER. The rechargeable Zn-air battery assembled with the as-obtained Fe/Fe3C@FeNC catalyst as a cathode offered a high peak energy density of 134.6 mW cm-2, high specific capacity of 856.2 mA h gZn-1 and excellent stability over 180 h at 5 mA cm-2 (10 min per cycle) with a small charge/discharge voltage gap of ∼0.851 V. This work presents a practical strategy for constructing nitrogen-rich catalysts with stable 3D structures.

Chromosomal microarray analysis vs. karyotyping for fetal ventriculomegaly: a meta-analysis.

BACKGROUND: Chromosomal abnormalities are important causes of ventriculomegaly (VM). In mild and isolated cases of fetal VM, obstetricians rarely give clear indications for pregnancy termination. We aimed to calculate the incidence of chromosomal abnormalities and incremental yield of chromosomal microarray analysis (CMA) in VM, providing more information on genetic counseling and prognostic evaluation for fetuses with VM. METHODS: The Chinese language databases Wanfang Data, China National Knowledge Infrastructure, and China Biomedical Literature Database (from January 1, 1991 to April 29, 2020) and English language databases PubMed, Embase, and Cochrane Library (from January 1, 1945 to April 29, 2020) were systematically searched for articles on fetal VM. Diagnostic criteria were based on ultrasonographic or magnetic resonance imaging (MRI) assessment of lateral ventricular atrium width: ≥10 to <15 mm for mild VM, and ≥15 mm for severe VM. Isolated VM was defined by the absence of structural abnormalities other than VM detected by ultrasonography or MRI. R software was used for the meta-analysis to determine the incidence of chromosomal abnormalities and incremental yield of CMA in VM, and the combined rate and 95% confidence interval (CI) were calculated. RESULTS: Twenty-three articles involving 1635 patients were included. The incidence of chromosomal abnormalities in VM was 9% (95% CI: 5%-12%) and incremental yield of CMA in VM was 11% (95% CI: 7%-16%). The incidences of chromosomal abnormalities in mild, severe, isolated, and non-isolated VM were 9% (95% CI: 4%-16%), 5% (95% CI: 1%-11%), 3% (95% CI: 1%-6%), and 13% (95% CI: 4%-25%), respectively. CONCLUSIONS: Applying CMA in VM improved the detection rate of abnormalities. When VM is confirmed by ultrasound or MRI, obstetricians should recommend fetal karyotype analysis to exclude chromosomal abnormalities. Moreover, CMA should be recommended preferentially in pregnant women with fetal VM who are undergoing invasive prenatal diagnosis. CMA cannot completely replace chromosome karyotype analysis.

Comparative analysis of vaspin in pregnant women with and without gestational diabetes mellitus and healthy non-pregnant women.

To explore serum vaspin, leptin, and adiponectin levels and their correlation with insulin resistance (IR) in pregnant women with and without gestational diabetes mellitus (GDM) and healthy non-pregnant women. A total of 262 individuals, including pregnant women with GDM (n = 86), those without GDM (n = 92), and age-matched healthy non-pregnant women (n = 84) were enrolled in this case-control study. Vaspin, leptin, adiponectin, glucose, insulin, hemoglobin A1C (HbA1c), and lipid parameters were measured. The homeostasis model assessment-insulin resistance (HOMA-IR), quantitative insulin sensitivity check index, and body mass index were calculated. Data inferred higher concentrations of vaspin (2.72 ± 2.20 vs. 1.84 ± 1.57 vs. 0.81 ± 1.02) in GDM than during normal pregnancy and in non-pregnant women, higher leptin (23.42 ± 12.18 vs. 22.19 ± 10.55 vs. 12.10 ± 11.26), and lower adiponectin (4,164.83 ± 2,650.39 vs. 4,871.66 ± 2,803.51 vs. 7,202.85 ± 4,893.13) in GDM and normal pregnancy as compared to non-pregnant women (p < 0.05). Vaspin was positively correlated to leptin (r = 0.273, p = 0.012), HOMA-IR (r = 0.387, p = 0.000), and triglycerides (TG, r = 0.218, p = 0.046) in GDM. In addition, leptin was negatively correlated to adiponectin in GDM (r = -0.336, p = 0.002) and normal pregnancy (r = -0.256, p = 0.014). Furthermore, vaspin was significantly correlated to GDM and HOMA-IR, and the weight gain might play a vital role in the occurrence of GDM. During pregnancy, high vaspin concentration is significantly associated with IR in GDM.