Search

Novel core-shell structured CoNi2S4@polydopamine nanocomposites have been successfully developed as advanced electrode materials for supercapacitors. The CoNi2S4 nanoparticles are tightly wrapped by polydopamine, forming a hierarchical core/shell network, which benefits the improvement of the electrochemical properties. The electrochemical performance of the as-prepared materials had been investigated by cyclic voltammetry and galvanostatic charge/discharge tests. Specific capacitances of CoNi2S4 and CoNi2S4@polydopamine are 425 and 725 F g−1 at 10 A g−1 respectively. Electrochemical impedance spectroscopy results suggest that the coating of polydopamine can reduce the charge transfer resistance and increase the diffusion rate of the electrolytic ion efficiently. The superior pseudocapacitive performance of CoNi2S4@polydopamine can be ascribed to the unique core-shell heterostructure and the combined contribution of the electrochemical active CoNi2S4 and the conductive polydopamine. [ABSTRACT FROM AUTHOR]

Sn/graphene/polydopamine ternary nanocomposites have been synthesized through a facile precipitation method. Sn nanoparticles are closely wrapped by graphene in the nanocomposites as compared to Sn/graphene, which is beneficial not only to reduce the volumetric change but also to boost the conductivity of the nanocomposites. The lithium storage properties of the materials have been investigated by cyclic voltammetry measurements and charge/discharge cycling. The obtained Sn/graphene/polydopamine nanocomposites deliver a high capacity of 626 mAh g−1 after 200 cycles at the current density of 500 mA g−1, which is superior to Sn/graphene. Electrochemical impedance spectroscopy measurements suggest that the introduction of polydopamine decreases the interface resistance of the composites and increases the conductivity of electrons efficiently. [ABSTRACT FROM AUTHOR]

To utilize the lignite residues after humic acid extraction, experimental studies on pyrolysis of Xianfeng lignite residue (XLR) were conducted with a fixed-bed reactor under nitrogen atmosphere in the temperature range of 500-900 °C. The product gas yield and composition, and the properties of solid product were investigated and compared with those obtained from pyrolysis of Xianfeng lignite (XL). The results showed that the gas yield of dry-ash-free XLR was higher than that of XL and the content of CO in the product gas increased rapidly with increasing temperature. The surface area of the char from XLR pyrolysis increased as the pyrolysis temperature increased, which reached a high value of 612 m2/g at 900 °C compared to only 10 m2/g for the char obtained from XL pyrolysis. The porosity development in the former was due to the activation of carbon in the char matrix with Na-containing groups leading to the formation of micropores and mesopores in the solids, which could be potentially useful as adsorbents. [ABSTRACT FROM AUTHOR]

Coal-derived activated carbon/CoO nanocomposites have been prepared via a facile two-step synthetic strategy. Results indicate that CoO nanoparticles possess a uniform distribution on the surface of coal-derived activated carbon. The electrochemical performance of the as-prepared samples had been investigated by cyclic voltammetry and galvanostatic charge/discharge measurement. Results suggest that the nanocomposites exhibit higher specific capacitance than bare CoO and coal-derived activated carbon. The superior capacitive performance is further illustrated by electrochemical impedance spectroscopy measurement, which demonstrates that the introduction of coal-derived activated carbon in the nanocomposites can not only improve the electron transfer but also promote the electrolyte penetration. [ABSTRACT FROM AUTHOR]

B-cell activating factor (BAFF) is involved in not only physiology of normal B cells, but also pathophysiology of aggressive B cells related to malignant and autoimmune diseases. Rapamycin, a lipophilic macrolide antibiotic, has recently shown to be effective in the treatment of human lupus erythematosus. However, how rapamycin inhibits BAFF-stimulated B-cell proliferation and survival has not been fully elucidated. Here, we show that rapamycin inhibited human soluble BAFF (hsBAFF)-induced cell proliferation and survival in normal and B-lymphoid (Raji and Daudi) cells by activation of PP2A and inactivation of Erk1/2. Pretreatment with PD98059, down-regulation of Erk1/2, expression of dominant negative MKK1, or overexpression of wild-type PP2A potentiated rapamycin's suppression of hsBAFF-activated Erk1/2 and B-cell proliferation/viability, whereas expression of constitutively active MKK1, inhibition of PP2A by okadaic acid, or expression of dominant negative PP2A attenuated the inhibitory effects of rapamycin. Furthermore, expression of a rapamycin-resistant and kinase-active mTOR (mTOR-T), but not a rapamycin-resistant and kinase-dead mTOR-T (mTOR-TE), conferred resistance to rapamycin's effects on PP2A, Erk1/2 and B-cell proliferation/viability, implying mTOR-dependent mechanism involved. The findings indicate that rapamycin inhibits BAFF-stimulated cell proliferation/survival by targeting mTOR-mediated PP2A-Erk1/2 signaling pathway in normal and neoplastic B-lymphoid cells. Our data highlight that rapamycin may be exploited for preventing excessive BAFF-induced aggressive B-cell malignancies and autoimmune diseases. [ABSTRACT FROM AUTHOR]