High-rate asymmetrical supercapacitors based on cobalt-doped birnessite nanotubes and Mn-FeOOH nanotubes.

Co-Doped MnO2 nanotubes (Co-MnO2-5) were prepared as the positive electrode of supercapacitors via a simple one-step hydrothermal method. Co doping and one-dimensional tunneling of nanotubes result in low internal resistance and good ionic contact, enhancing the conductivity and electrochemical performance of the electrodes.

Morphology-controlled MnO2-graphene oxide-diatomaceous earth 3-dimensional (3D) composites for high-performance supercapacitors.

3-Dimensional (3D) composites based on a unique combination of MnO2-nanostructures, graphene oxide nanosheets and porous Diatomaceous Earth (DE) microparticles (GO-DE@MnO2) were synthesized and explored for application in high-performance supercapacitors. To explore the influence of the structural properties of MnO2 nanostructures on supercapacitor performances, several MnO2 structures with nanosheet and nanowire morphologies were synthesized and characterized. The prepared GO-DE@MnO2 composites with MnO2 nanosheets due to their higher conductivity and higher surface area showed a larger specific capacitance of 152.5 F g(-1) and a relatively better cycle stability (83.3% capacitance retention after 2000 cycles at a scan rate of 2 A g(-1)), indicating great potential for application in supercapacitors.

Rational design of octahedron and nanowire CeO2@MnO2 core-shell heterostructures with outstanding rate capability for asymmetric supercapacitors.

Two kinds of novel CeO2@MnO2 nanostructures have been synthesized via a self-assembly strategy. The as-prepared CeO2 nanowire@MnO2 nanostructures exhibited unprecedented pseudocapacitance performance (255 F g(-1)) with outstanding rate capability. A new mechanism based on the synergistic effect between CeO2 and MnO2 was proposed to interpret this phenomenon. When assembled as an asymmetric supercapacitor, an energy density of 27.5 W h kg(-1) with a maximum power density of 1.6 kW kg(-1) was achieved for CeO2 nanowire@MnO2 nanostructures.

Analysis of risk factors of acute ischemic stroke for different ethnic groups in Changde.

OBJECTIVES: The aim of our study was to explore the risk factors of acute ischemic stroke (AIS) for different ethnic groups in Changde city (a multi-ethnic residence inhabited mainly by Han and Tujia), Hunan Province, China. DESIGN, SETTING AND PARTICIPANTS: A multicenter study was performed and the demography data, etiology data and clinical features of 5338 AIS patients from 17 hospitals in Changde city were collected from January 2011 through December 2011. MAIN MEASURES: Student's t-test and Chi2-test were used to compare the differences between the Han and Tujia ethnic group in the AIS. RESULTS: In Changde, the incidence of AIS in the Tujia ethnic group was higher than that in the Han ethnic group (233.14 per million vs. 84.38 million, respectively). We found statistically significant differences between the Tujia and Han ethnicities in demographic, etiology and clinical data (eg, sex, living environment, diet, smoking, payment methods, cerebral hemorrhage and transient ischemic attack [P < .05]). In addition, compared with the Han population, the Tujia patients had a higher rate of the incidence of the anterior circulation infarction, partial anterior circulation infarction, lacunar infarction and cerebral hemorrhage. CONCLUSIONS: Our results indicate that lifestyle choices (eg, diet, smoking cigarettes), location, family heritage, and sex are associated with AIS and is useful for informing AIS rates and treatment for AIS.