One-step synthesis of a sulfur-impregnated graphene cathode for lithium-sulfur batteries.

A practical route is introduced for synthesizing a sulfur-impregnated graphene composite as a promising cathode material for lithium-sulfur batteries. Sulfur particles with a size of a few microns are successfully grown in the interior spaces between randomly dispersed graphene sheets through a heterogeneous crystal growth mechanism. The proposed route not only enables the control of the particle size of active sulfur but also affords quantitative yields of composite powder in large quantities. We investigate the potential use of the sulfur-impregnated graphene composite as a cathode material owing to its advantages of confining active sulfur, preventing the dissolution of soluble polysulfides, and providing sufficient electrical conduction. A high discharge capacity of 1237 mA h g(-1) during the first cycle and a good cyclic retention of 67% after 50 cycles are attained in a voltage range of 1.8-2.6 V vs. Li/Li(+). These results emphasize the importance of tailoring cathode materials for improving the electrochemical properties of lithium-sulfur batteries. Our results provide a basis for further investigations on advanced lithium batteries.

Novel catalytic effects of Mn3O4 for all vanadium redox flow batteries.

A new approach for enhancing the electrochemical performance of carbon felt electrodes by employing non-precious metal oxides is designed. The outstanding electro-catalytic activity and mechanical stability of Mn(3)O(4) are advantageous in facilitating the redox reaction of vanadium ions, leading to efficient operation of a vanadium redox flow battery.

Genetic changes in bilateral breast cancer by comparative genomic hybridisation.

The aim of this study is to find any specific genetic defect occurring frequently in bilateral breast cancer by examining the genetic changes of each chromosome using comparative genomic hybridisation (CGH). CGH was conducted for 36 breast cancer tissues taken from patients treated with surgery for bilateral breast cancer. Tumour and control DNAs were hybridised to metaphase chromosome with differential staining with fluorescein and rhodamine-dUTP. An average rate of green (DNA of tumour cell) against red (DNA of a normal peripheral blood lymphocyte) was calculated in these captured metaphase chromosomes and a ratio of more than 1.17 was defined as an acquisition, less than 0.85 as a loss and, finally, more than 2 as amplification. Twenty-six out of 36 cases (72.2%) showed a change in the number of DNA copies by CGH in one or more regions of gene. On average, 5.3 alterations for each chromosome (range, 1-14) were found, and gain was present more than loss at a ratio of 1.3:1. Loci that showed amplification were X, 17q, Xq, 8q, 14q11-21 and 17q22-qter. The locus showing the most gain was the X chromosome, which was observed in 15 (57.7%) out of 26 cases. Loss was most frequently observed in the short arm of chromosome 8. The concordance of genetic transformation of primary cancer and secondary cancer in bilateral breast cancer was an average of 18.7% in synchronous and 10.7% in metachronous cancer, showing higher similarity in synchronous breast cancer.

Retinal nerve fiber layer thickness in the fellow eyes of normal-tension glaucoma patients with unilateral visual field defect.

PURPOSE: To quantitatively evaluate retinal nerve fiber layer (RNFL) thickness in the fellow eyes of normal-tension glaucoma (NTG) patients with unilateral visual field defect. DESIGN: Observational case-control study. METHODS: Twenty-nine NTG patients with unilateral visual field defect were enrolled in this study. All 29 fellow eyes showed normal visual field. Thirty-one normal eyes of 31 subjects served as controls. The RNFL thickness around the optic disk was determined using Fast RNFL thickness (3.4) of optical coherence tomography. Average and segmental (4 quadrants and 12 clock- hours) RNFL thickness measurements were compared among the three groups. RESULTS: RNFL thicknesses were significantly different among the three groups in the average, superior quadrant (11 and 12 clock-hour segments), and inferior quadrant (6 clock-hour segment) (P = .00, one-way ANOVA and Tukey's tests). CONCLUSIONS: RNFL thickness reductions are already present in the fellow eyes of NTG patients with unilateral visual field defect.