A novel robust adsorbent for efficient oil/water separation: Magnetic carbon nanospheres/graphene composite aerogel.

Recently, graphene aerogels (GAs) have attracted considerable research attention in oil/water separation owing to their remarkable properties. However, the serious stacking of graphene oxide nanosheets (GO) would lead to low adsorption capacity and poor recyclability. For the first time, with alkaline ammonium citrate as reducing agent and nitrogen source, the point-to-face contact between magnetic carbon nanospheres (MCNS) and graphene sheets was adopted to effectively inhibit the aggregation of graphene sheets. Nitrogen-doped magnetic carbon nanospheres/graphene composite aerogels (MCNS/NGA) were fabricated under weakly alkaline conditions by one-step hydrothermal in-situ electrostatic self-assembling strategy. The aerogels have low density, super-elasticity (up to 95 % compression), high specific surface area (787.92 m2 g-1) and good magnetic properties. Therefore, they exhibit adsorption capacity in the range of 187-537 g g-1 towards various organic solvents and oils, superior to most reported materials to date. In addition, thanks to their good mechanical properties, excellent thermal stability and flame retardancy, they can be regenerated by squeezing, distillation and combustion. More importantly, magnetic control technology can be adopted to realize oriented adsorption and facilitate recycling of organic solvents and oils in extreme environments.

Pulse electrochemical synthesis of polypyrrole/graphene oxide@graphene aerogel for high-performance supercapacitor.

A novel electroactive polypyrrole/graphene oxide@graphene aerogel (PGO@GA) was synthesized for the first time by pulse electropolymerization. The off-time in this technique allows polypyrrole (PPy) to go through a more stable structural arrangement, meanwhile its electronic transmission performance is enhanced by immobilizing graphene oxide between PPy chains. Moreover, graphene aerogel provides a three-dimensional structure with high conductivity to protect PPy from swelling and shrinking during the capacitive testing. Under these synergistic effects, PGO@GA presents exceptional capacitive performances including high specific capacitance (625 F g-1 at 1 A g-1), excellent rate capability (keeping 478 F g-1 at 15 A g-1 with retention rate of 76.5%), and excellent cycling life (retaining 85.7% of its initial value when cycling 5000 times at 10 A g-1). Therefore, the strategy adopted by this research provides a good reference for preparing other PPy-based electrode materials applied in the fields of catalysis, sensing, adsorption and energy storage.

Multifunctional nitrogen-doped graphene nanoribbon aerogels for superior lithium storage and cell culture.

Nitrogen-doped graphene nanoribbon aerogels (N-GNRAs) are fabricated through the self-assembly of graphene oxide nanoribbons (GONRs) combined with a thermal annealing process. Amino-groups are grafted to the surface of graphene nanoribbons (GNRs) by an epoxy ring-opening reaction. High nitrogen doping level (7.6 atm% as confirmed by elemental analysis) is achieved during thermal treatment resulting from functionalization and the rich edge structures of GNRs. The three dimensional (3D) N-GNRAs feature a hierarchical porous structure. The quasi-one dimensional (1D) GNRs act as the building blocks for the construction of fishnet-like GNR sheets, which further create 3D frameworks with micrometer-scale pores. The edge effect of GNRs combined with nitrogen doping and porosity give rise to good electrical conductivity, superhydrophilic, highly compressible and low density GNRAs. As a result, a high capacity of 910 mA h g(-1) is achieved at a current density of 0.5 A g(-1) when they are tested as anode materials for lithium ion batteries. Further cell culture experiments with the GNRAs as human medulloblastoma DAOY cell scaffolds demonstrate their good biocompatibility, inferring potential applications in the biomedical field.

Targeted Fe-filled carbon nanotube as a multifunctional contrast agent for thermoacoustic and magnetic resonance imaging of tumor in living mice.

Microwave-induced thermoacoustic imaging (TAI) can map the microwave absorption distribution of targets, which depends on the electrical and magnetic properties. Although carbon nanotubes (CNTs) with good electrical properties have been used as TAI contrast agents, the negligible magnetic absorption hinders its application for sensitive detection. In order to exploit CNTs with electrical and magnetic absorption properties as agent of TAI, the ferromagnetic material-filled multi-walled CNTs (MMWCNTs) are investigated. In this study, the folic acid conjugated plain multiwalled CNTs (MWCNTs) and MMWCNTs were injected through the tail-vein of mice separately, and TAI and magnetic resonance imaging (MRI) were performed. The results show the MMWCNTs can clearly image the size and edge of the tumor with the TAI contrast enhancement of 67% and T2 signal intensity decrease of four fifths compared to MWCNTs. This study demonstrated the hybrid particles have the potential to be a high-sensitive contrast agent for accurate tumor detection. From the Clinical Editor: Novel imaging modalities are emerging. Microwave-induced thermoacoustic imaging (TAI) relies on the absorption distribution of microwave of targets. In this article the authors investigate the use of ferromagnetic material-filled multi-walled CNTs as contrast agents for both TAI and MRI in an in-vivo model for tumors. The positive findings would imply that the application of dual-modality probe could provide more accurate imaging for the clinical setting.

Self-Sensing, Ultralight, and Conductive 3D Graphene/Iron Oxide Aerogel Elastomer Deformable in a Magnetic Field.

Three-dimensional (3D) graphene aerogels (GA) show promise for applications in supercapacitors, electrode materials, gas sensors, and oil absorption due to their high porosity, mechanical strength, and electrical conductivity. However, the control, actuation, and response properties of graphene aerogels have not been well studied. In this paper, we synthesized 3D graphene aerogels decorated with Fe3O4 nanoparticles (Fe3O4/GA) by self-assembly of graphene with simultaneous decoration by Fe3O4 nanoparticles using a modified hydrothermal reduction process. The aerogels exhibit up to 52% reversible magnetic field-induced strain and strain-dependent electrical resistance that can be used to monitor the degree of compression/stretching of the material. The density of Fe3O4/GA is only about 5.8 mg cm(-3), making it an ultralight magnetic elastomer with potential applications in self-sensing soft actuators, microsensors, microswitches, and environmental remediation.

High expression of metadherin correlates with malignant pathological features and poor prognostic significance in papillary thyroid carcinoma.

BACKGROUND: Metadherin (MTDH) protein, also called astrocyte elevated gene-1 (AEG-1) is over expressed in a variety of malignant tumours, and is closely related to tumour invasion and the poor prognosis. OBJECTIVE: This study tries to explore the clinical pathological significance of MTDH expression in a large cohort of patients with PTC. DESIGN AND PATIENTS: Immunohistochemistry was used to detect MTDH expression in 156 cases of PTC, 6 cases of anaplastic thyroid carcinoma (ATC), 10 cases of multinodular goitre (MNG) and 10 cases of thyroid adenoma tissues who received a thyroid operation between June 2003 and July 2008. MEASUREMENTS: Clinical pathological data of 156 cases of PTC were analysed according to MTDH expression. The Kaplan-Meier method was used to plot survival curves and log-rank test to compare the postoperative survival results. The prognostic meaning of MTDH expression in PTC was evaluated by Cox regression analysis. RESULTS: The positive expression rates of MTDH in PTC and ATC tissues were 37·2% (58/156) and 50% (3/6), respectively, and MTDH positive expression rates were both 10% (1/10) in MNG and thyroid adenoma tissues. High MTDH expression in PTC was associated with larger tumour size (P = 0·030), high rates of lymph node (P = 0·041) and distant metastasis (P = 0·028), but no relation with the patient age, gender, tumour multicenter, extrathyroid invasion and tumour grade. High MTDH expression was associated with recurrence-free survival (RFS) and disease-specific survival rate (DSS) (P = 0·014, P = 0·001, respectively). Cox regression analysis showed that high MTDH expression was independent prognostic indicators for RFS and DSS in patients with PTC (P = 0·023 and P = 0·035, respectively). CONCLUSION: High MTDH expression in PTC might play an important role in tumour growth and metastasis, and targeting MTDH treatment might have potential therapeutic value for patients with PTC.

Synergistic cytotoxic effect of genistein and doxorubicin on drug-resistant human breast cancer MCF-7/Adr cells.

The molecular mechanisms underlying genistein-mediated reversal of chemoresistance remains unknown. In the present study, we investigated the molecular mechanisms by which genistein overcomes chemoresistance and its effect on doxorubicin-induced cytotoxicity. Consistent with previous reports, genistein combined with doxorubicin had a synergistic effect on MCF-7/Adr cells, and genistein reduced the chemoresistance of these cells. Genistein treatment increased the intracellular accumulation of doxorubicin but did not influence P-gp function. The combination of genistein and doxorubicin significantly induced cell cycle arrest and apoptosis. Genistein treatment strongly inhibited HER2/neu but not MDR-1 expression at both the mRNA and protein levels. Therefore, our results demonstrated that genistein combined with doxorubicin had a synergistic effect on MCF-7/Adr cells, and the mechanisms likely involve an increase in the intracellular accumulation of doxorubicin and suppression of HER2/neu expression.

High expression of KIF26B in breast cancer associates with poor prognosis.

To date, a great number of studies have demonstrated that altered expression of kinesins is associated with development and progression of various human cancers. Kinesin family member 26B (KIF26B), a member of the kinesin superfamily proteins (KIFs), is essential for kidney development. However, the role of KIF26B during tumorigenesis and progression is limited. Here, we demonstrate that both KIF26B mRNA and protein are overexpression in breast cancer tissues by RT-qPCR and western blot. Immunohistochemistry revealed that KIF26B expression significantly correlated with clinicopathological factors, including tumor size (P = 0.011), grade (P = 0.017), lymph node status (P = 0.009) and ER status (P = 0.012). Moreover, the Kaplan-Meier analysis indicated that breast cancer patients with high KIF26B expression had a shorter survival than those with low KIF26B expression. In addition, multivariate analysis indicated that KIF26B is an independent prognostic for outcome in breast cancer (HR, 2.356; 95%CI, 1.268-4.378; P = 0.007). Collectively, our study demonstrated that KIF26B was overexpression in breast cancer and could be served as a potential prognostic marker.

Investigation of the role of surface chemistry and accessibility of cadmium adsorption sites on open-surface carbonaceous materials.

Carbon nanotubes fabricated by the dc arc discharge method (ADCNTs) and chemical vapor deposition method (CVDCNTs) were oxidized with concentrated HNO 3 to modify their surface chemistry. The materials were characterized using SEM, TEM, FTIR, XPS, potentiometric titration, and nitrogen adsorption. The initial and oxidized materials were used as adsorbents of cadmium from aqueous solutions with different pH. Langmuir and Freundlich adsorption models were applied to fit the isotherm data, and both models fit the experimental data very well. The acid oxidation resulted in an increase in the number of oxygen-containing groups without drastic changes in the texture of the adsorbents. Although the small volume of micropores is present, the nanotube structure can be considered as nonporous. The lack of developed microporosity in carbonaceous materials eliminates the inner surface diffusion problems and makes the vast majority of surface groups available for adsorption of cadmium. The availability of these centers depends on the pH of the solution, which controls the protonation level. In spite of the fact that the pH of the solution affects the speciation of cadmium to some degree, the surface chemistry is the predominant force for adsorption at the pH range adopted in the present study, while the texture of materials also affects the nanotube's cadmium-adsorbing performance.