Charge transfer induced activity of graphene for oxygen reduction.

Tetracyanoethylene (TCNE), with its strong electron-accepting ability, was used to dope graphene as a metal-free electrocatalyst for the oxygen reduction reaction (ORR). The charge transfer process was observed from graphene to TCNE by x-ray photoelectron spectroscopy and Raman characterizations. Our density functional theory calculations found that the charge transfer behavior led to an enhancement of the electrocatalytic activity for the ORR.

Carbon-coated MoS2 nanosheets as highly efficient electrocatalysts for the hydrogen evolution reaction.

As a green and highly efficient energy resource, hydrogen (H2) has attracted much attention in recent years. Electrochemical water splitting is an economic process to generate H2. MoS2 is a promising candidate to replace traditional Pt-based electrocatalysts for the hydrogen evolution reaction (HER) under acidic conditions. But low electrical conductivity is one of bottlenecks for the large-scale application of MoS2. In this work, a carbon-coated MoS2 hybrid electrocatalyst was prepared with a chemical vapour deposition (CVD) approach to improve the electrical conductivity of MoS2. In addition to the surface-coating carbon, a small graphene-like layer could also be inserted into the interlayers of MoS2 during the CVD process which resulted in more active sites being exposed in MoS2. Enhanced electrical conductivity and more exposed active sites lead to excellent HER activity.

[Immunophenotypic Analysis of Patients with CD56⁺ Acute Myeloid Leukemia].

OBJECTIVE: To explore the immunophenotype characteristics of newly diagnosed patients with CD56⁺ acute myeloid leukemia (AML). METHODS: Combining with cytomorphology, four-color flow cytometry was used to analyze the immunophenotype of 342 AML patients with CD56⁺ or CD56⁻. RESULTS: In 342 AML patients, the CD56⁺ expression was found in 83 AML patients who accounted for 24.27% and included 10 cases of M1, 45 cases of M2, 5 cases of M3, 6 cases of M6 and 17 cases of M5. The statistical analysis showed that there was statistical difference between CD56⁺ and CD11b⁺ patients (P < 0.05), but there was no statistical difference between CD56⁺ and HLA-DR, CD34, CD38, CD13, CD33, CD15, CD117, CD14, CD64, CD2, CD7, CD5, CD3, CD4, CD10, CD19, CD20, CD22 (P > 0.05). CONCLUSION: AML with only CD56 positive always has poor prognosis, thus the prognosis of patients with CD56⁺ AML accompanied by other antigens still needs more research.

Ultrathin Wrinkled N-Doped Carbon Nanotubes for Noble-Metal Loading and Oxygen Reduction Reaction.

We describe the fabrication of ultrathin wrinkled N-doped carbon nanotubes by an in situ solid-state method. The positions of Co catalyst were first labeled by good-dispersion and highly loaded Au and Pt, indicating the most of Co are unsealed. The resultant unique nanoarchitecture, which exhibits the features of carbon nanotube and graphene with a combined effect of 1D and 2D carbon-based nanostructures, exhibited a superior ORR activity to carbon nanotubes and graphene. Moreover, the novel catalysts showed a better durability and higher tolerance to methanol crossover and poisoning effects than those of Pt/C.

Expression patterns of CD200 and CD148 in leukemic B-cell chronic lymphoproliferative disorders and their potential value in differential diagnosis.

Different combinations of biomarkers analyzed by flow cytometry are critical for the accurate diagnosis of leukemic B-cell chronic lymphoproliferative disorders (B-CLPDs). We investigated CD200 and CD148 expression patterns of blood or bone marrow from 374 cases of B-CLPD by multicolor flow cytometry. Our results showed that CD200 and CD148 expression patterns distinguished different types of B-CLPD. CD200 mean fluorescence intensity (MFI) or CD148 MFI had a high sensitivity and specificity to differentiate mantle cell lymphoma (MCL) from chronic lymphocytic leukemia (CLL). Furthermore, CD148 MFI/CD200 MFI ratio>4.79 produced a specificity of 94.46% (95% confidence interval [CI]: 91.04-96.87%) and a sensitivity of 100% (95% CI: 88.78-100.0%) in establishing the diagnosis of MCL in differential diagnosis between MCL and CLL. We therefore conclude that the combination of CD200 and CD148 may have a potential differential diagnostic value in leukemic B-CLPDs, especially between CLL and MCL.

Sulfur-doped graphene derived from cycled lithium-sulfur batteries as a metal-free electrocatalyst for the oxygen reduction reaction.

Heteroatom-doped carbon materials have been extensively investigated as metal-free electrocatalysts to replace commercial Pt/C catalysts in oxygen reduction reactions in fuel cells and Li-air batteries. However, the synthesis of such materials usually involves high temperature or complicated equipment. Graphene-based sulfur composites have been recently developed to prolong the cycling life of Li-S batteries, one of the most attractive energy-storage devices. Given the high cost of graphene, there is significant demand to recycle and reuse graphene from Li-S batteries. Herein, we report a green and cost-effective method to prepare sulfur-doped graphene, achieved by the continuous charge/discharge cycling of graphene-sulfur composites in Li-S batteries. This material was used as a metal-free electrocatalyst for the oxygen reduction reaction and shows better electrocatalytic activity than pristine graphene and better methanol tolerance durability than Pt/C.

[Expression characteristics of CD200 in acute myeloid leukemia and its clinical significance].

This study was aimed to investigate the relationship between expression of CD200 antigen and clinical characteristics in AML patients and to analyse the value of CD200 in evaluation of AML prognosis. The CD200 and immunophenotypes were detected by flow cytometry, the chromosome karyotypes were determined by R banding, the FISH was used to measure the AML1/ETO, PML/RARa and inv(16), and PCR technique was used to detect the fusion genes AML1/ETO and PML/RARα. The results showed that the positive rate of CD200 antigen expression in 54 patients was 57.4% (31/54), the CD200 antigen expression between sex and age of patients was no significant different (P > 0.05). There was significant difference of CD200 expression between CD34 and CD117 (P < 0.05), but the difference of CD200 expression in chromosome karyotypes was no significant difference(P > 0.05). Moreover, there was significant difference of CD200 expression in CD34 and CD117 of CBF positive AML patients (P < 0.05). It is concluded that the CD200 antigen expression in AML may associate with a poor prognosis of patients.

Molecular doping of graphene as metal-free electrocatalyst for oxygen reduction reaction.

In this work, we successfully, for the first time, perform the molecular doping of graphene as metal-free electrocatalysts for oxygen reduction reaction. The doped small molecule onto graphene could induce the charge transfer between graphene and the molecules, which leads to significantly enhanced electrocatalytic activity for oxygen reduction reaction.

Oxygen reduction reaction in a droplet on graphite: direct evidence that the edge is more active than the basal plane.

Carbon-based metal-free electrocatalysts for the oxygen reduction reaction (ORR) in alkaline medium have been extensively investigated with the aim of replacing the commercially available, but precious platinum-based catalysts. For the proper design of carbon-based metal-free electrocatalysts for the ORR, it would be interesting to identify the active sites of the electrocatalyst. The ORR was now studied with an air-saturated electrolyte solution droplet (diameter ca. 15 µm), which was deposited at a specified position either on the edge or on the basal plane of highly oriented pyrolytic graphite. Electrochemical measurements suggest that the edge carbon atoms are more active than the basal-plane ones for the ORR. This provides a direct way to identify the active sites of carbon materials for the ORR. Ball-milled graphite and carbon nanotubes with more exposed edges were also prepared and showed significantly enhanced ORR activity. DFT calculations elucidated the mechanism by which the charged edge carbon atoms result in the higher ORR activity.

One-pot synthesis of nitrogen and sulfur co-doped graphene as efficient metal-free electrocatalysts for the oxygen reduction reaction.

Novel N, S co-doped graphene (NSG) was prepared by annealing graphene oxide with thiourea as the single N and S precursor. The NSG electrodes, as efficient metal-free electrocatalysts, show a direct four-electron reaction pathway, high onset potential, high current density and high stability for the oxygen reduction reaction.