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Rationale and Objectives To characterize online news coverage relating to mammography, including articles' stance toward screening mammography. Materials and Methods Google News was used to search U.S. news sites over a 9-year period (2006–2015) based on the search terms “mammography” and “mammogram.” The top 100 search results were recorded. Identified articles were manually reviewed. Results The top 100 news articles were from the following sources: local news outlet (50%), national news outlet (24%), nonimaging medical source (13%), entertainment or culture news outlet (6%), business news outlet (4%), peer-reviewed journal (1%), and radiology news outlet (1%). Most common major themes were the screening mammography controversy (29%), description of a new breast imaging technology (23%), dense breasts (11%), and promotion of a public screening initiative (11%). For the most recent year, article stance toward screening mammography was 59%, favorable; 16%, unfavorable; and 25%, neutral. After 2010, there was an abrupt shift in articles' stances from neutral to both favorable and unfavorable. Conclusions A wide range of online news sources addressed a range of issues related to mammography. National, rather than local, news sites were more likely to focus on the screening controversy and more likely to take an unfavorable view. The controversial United States Preventive Services Task Force guidelines may have influenced articles to take a stance on screening mammography. As such online news may impact public perception of the topic and thus potentially impact guideline adherence, radiologists are encouraged to maintain awareness of this online coverage and to support the online dissemination of reliable and accurate information.

Carbon counter electrodes for dye-sensitized solar cells (DSSCs) have attracted great interest recently because of their low cost, excellent catalytic activity, and superior chemical stability, which are potential alternatives to expensive Pt electrodes for the large-scale DSSCs application. In this perspective, the recent significant progress in preparing various forms of carbon counter electrodes for DSSCs is systematically summarized, and the pivotal factors in determining catalytic performance of carbon counter electrodes is highlighted in detail. Besides, in order to further optimize catalytic activity of various carbon materials for high-performance DSSCs, we also selectively discuss and summarize the effective strategies to enhance the short circuit current, tune the open circuit voltage, and improve the fill factor of DSSC by modulating the physical and chemical properties of carbon counter electrodes. Finally, the main problems and challenges in preparing and applying various carbon counter electrodes in DSSCs are addressed, which are in urgent need to be solved and thus may contribute to design highly efficient carbonaceous electrocatalysts for high-performance DSSCs in future.

N/P co-doped carbon nanosheets (NPC) have been prepared by a simply direct pyrolysis method using amino tris(methylene phosphonic acid) (ATMP) as carbon, nitrogen and phosphorus co-sources, and utilized as Pt-free counter electrodes (CEs) for dye-sensitized solar cells (DSSCs). The prepared N/P co-doped carbons with amorphous structure and platelet-like morphology exhibit rapid electrolyte diffusion. More importantly, the content of N/P dopants and doping states are temperature-dependent, and particularly the N/P dopants are easy to be eliminated at high temperature, accompanied with the introduction of defective sites into the carbon matrix, thus regulating the catalytically active sites and electrical conductivity of N/P co-doped carbon nanosheets. The electrochemical impedance spectroscopy, Tafel, and cyclic voltammetry measurements demonstrate that the NPC carbonized at 800 °C (NPC-800) with appreciable N/P doping content and suitable defective sites displays the best catalytic activity. As a consequence, the DSSC based on NPC-800 CE achieves a power conversion efficiency of 6.74%, which is higher than that of the cell with Pt CE (5.76%).

A new micro-nanostructured composite (NOMC-Ni@NCNTs) of Ni-encapsulated and N-doped carbon nanotubes (Ni@NCNTs) pinned on N-doped ordered mesoporous carbon (NOMC) is constructed by a two-step synthesis strategy. The strategy involves the self-assembly preparation of water-soluble phenolic resin/F127 colloid by a hydrothermal route and the subsequent catalytic pyrolysis of as-prepared phenolic resin/F127 copolymer and melamine with nickel acetate as Ni source and self-generated catalyst, leading to the in situ growth of dispersive Ni@NCNTs pinned on NOMC through the Ni junction. In the resultant NOMC-Ni@NCNTs, the NOMC shows reduced particle size and shortened mesopore channel length of 15–30 μm compared to 850 μm-2 mm of pristine NOMC. The pinned Ni@NCNTs constructs a 3D conductive scaffold in the composite and the conductivity is correspondingly raised from 20.4 S cm−1 of pristine NOMC to 254.1 S cm−1 of NOMC-Ni@NCNTs. The particle size, mesoporosity and surface area of NOMC-Ni@NCNTs composite are also flexibly regulated by tailoring the relative content of Ni@NCNTs and NOMC. The new-structured NOMC-Ni@NCNTs composites are developed as counter electrode (CE) materials for DSSCs, which demonstrates an excellent catalytic activity towards I 3 - reduction. The optimum NOMC-Ni@NCNTs CE delivers a low charge-transfer resistance of 2.21 Ω and the assembled DSSC achieves a high power conversion efficiency of 8.39%. Moreover, the NOMC-Ni@NCNTs CE based DSSC also manifests a preeminent electrochemical stability in corrosive I - / I 3 - electrolyte with a remnant efficiency of 7.82% after 72 h of illumination. The outstanding electrocatalytic performance is mainly correlated with their unique architecture, in which the pinned Ni@NCNTs conductive substrate accelerates the electron transportation among NOMC micron-particles, and the amorphous NOMC with short-range mesopores accelerates the electrolyte diffusion and supplies abundant ions-accessible defects for I 3 - reduction.

The composite electrocatalysts of cobalt oxide/mesoporous carbon and cobalt nitride/mesoporous carbon are synthesized via a convenient oxidation and subsequent ammonia nitridation of cobalt particles-incorporated mesoporous carbon, respectively. The cobalt oxide and nitride particles are uniformly imbedded in mesoporous carbon matrix, forming the unique composites with high surface area and mesopore architecture, and the resultant composites are evaluated as counter electrode materials, exhibiting good catalytic activity for the reduction of triiodide. The composites of cobalt nitride and mesoporous carbon are superior to the counterparts of cobalt oxide and mesoporous carbon in catalyzing the triiodide reduction, and the dye-sensitized solar cell with the composites achieves an optimum power conversion efficiency of 5.26%, which is comparable to the one based on the conventional Pt counter electrode (4.88%).

Amino tris(methylene phosphonic acid) (ATMP) is selected as phosphorus and carbon co-source for the synthesis of uniformly nano-sized LiFePO4/C by a quasi-sol–gel method. This strategy using ATMP instead of conventional NH4H2PO4 supplies two advantages: firstly, ATMP in situ chelates Li+ onto its framework and subsequently binds with FeC2O4 in aqueous solution, forming a molecule-scale homogeneous precursor which can obviously improve the purity of LiFePO4. Secondly, the organic carbon contained in ATMP can form uniformly distributed conductive carbon networks among LiFePO4 particles after calcination, which improves the electrical conductivity. The resultant LiFePO4/C with 1.1 wt.% carbon achieves a higher discharge capacity than those of LiFePO4 and LiFePO4/C prepared with inorganic NH4H2PO4. Moreover, core-shell structured LiFePO4/C nanocomposites are also fabricated by further introducing sucrose into the synthesis system. The high-quality carbon shell effectively hinders the LiFePO4 particle growth and aggregation under high-temperature treatment, which further enhances the electrical conductivity and lithium-ion diffusion, resulting in the improved electrochemical performance with excellent cycle stability (the optimum discharge capacity of 158.6 mAh g−1 at 0.1 C and 138.4 mAh g−1 at 2 C). The high purity, nanosize and core-shell structure of LiFePO4/C composites yielded by the novel synthesis strategy account for their outstanding electrochemical performance in high-power lithium-ion batteries.

A series of V-doped LiFePO4/C composites are synthesized through a quasi-sol–gel method using organophosphorus source. Amino tris(methylene phosphonic acid) is utilized as phosphorus and carbon co-precursor, sucrose as assisted carbon source, and NH4VO3 as dopant. The effect of vanadium doping on the structural property and electrochemical performance of LiFePO4/C cathode material is systematically investigated. Carbon is coated uniformly on the LiFePO4 nanoparticles and vanadium (+4) is incorporated into LiFePO4/C without altering the olivine structure. The appropriate V-doping refined LiFePO4 particle size, induced the lattice distortion and weakened the Li O bonds, leading to the enhancement of Li+ diffusion and electronic conductivity, and hence resulting in the improvement of the electrochemical performance of LiFePO4/C composites. A high rate discharge capacity of 140.2 mAh g−1 at 5 C, 120.4 mAh g−1 at 10 C, and 105.8 mAh g−1 at 20 C is obtained for LiFe0.97V0.03PO4/C. It is demonstrated that the simple and green synthesis process of the quasi-sol–gel route with organophosphonic acid as precursor is efficient to fabricate V-doped LiFePO4/C composite cathode materials for high-power lithium-ion batteries.

N-doped ordered cubic mesoporous carbons (N-OCMCs) are synthesized by a one-pot aqueous route from resorcinol and hexamethylenetetramine (HMT) and applied as counter electrode (CE) materials for dye-sensitized solar cells (DSSCs). The prepared N-OCMCs with ordered cubic mesoporous structure and large surface area offer appropriate electrolyte ions diffusion channels and abundant catalytically active sites for triiodide reduction. Moreover, the temperature dependence of nitrogen content and the nitrogen-doped types are demonstrated to play decisive roles in regulating the electrocatalytic activity of N-OCMC CEs and affecting the photovoltaic performance of DSSCs. The DSSCs based on the N-OCMC CEs achieve an optimum power conversion efficiency of 5.60%, as high as 86.7% of the cell based on the traditional Pt CE, due to that high N-doping amount, and particularly favorable pyridinic-N and graphtitic-N types promote the charge transport and transfer process of the carbon CE. The good catalytic performance could render N-OCMC as a cost-effective CE candidate to Pt in DSSC.

The composites of ordered mesoporous carbon (OMC) and graphene nano-sheets (GNS) are prepared by mixing OMC with different weight ratios of GNS, and utilized as counter electrode (CE) materials for dye-sensitized solar cells (DSSCs). Electrochemical impedance spectroscopy, Tafel polarization, and cyclic voltammetry measurements demonstrate that the OMC/GNS CEs display the enhanced electron transport property and fast reduction rate of I 3 − in comparison with those of the individual OMC and GNS CEs, due to the combination of superior electrical conductivity of GNS and good catalytic activity of OMC. Under AM 1.5 irradiation (100 mW cm−2), the DSSCs based on the OMC/GNS CEs show a maximum power conversion efficiency of 6.82%, which is comparable to 7.08% of the cell with the conventional Pt CE at the same experimental conditions, suggesting that the OMC/GNS composites are one of advanced CE materials for low-cost DSSCs.

Hierarchical porous carbons (HPCs) are prepared by a one-step hydrothermal route using soluble resols as a carbon source, polystyrene spheres and Pluronic F127 as macroporous and mesoporous templates, respectively. The resulting HPCs comprise continuous macro–meso–micropore networks on the carbon blocks, simultaneously exhibiting large surface areas (501–709 m2 g−1), which are particularly evaluated as counter electrodes (CEs) for dye-sensitized solar cells (DSSCs). Electrochemical impedance spectra (EIS), Tafel polarization curves, and cyclic voltammograms (CVs) demonstrate that the hierarchical pore system plays a crucial role in promoting the catalytic activities of the HPC CEs. In comparison with other porous carbon CEs, the HPC CEs with various macropores and appropriate micro/mesopores present better catalytic behaviors due to the easier accessibility for electrolyte ions and better utilization of the catalytically active sites, resulting in the higher photovoltaic conversion efficiencies of DSSCs. The optimum photovoltaic conversion efficiency of DSSCs based on HPC CEs is 7.22%, which can even match up to that of the cell with Pt CE (7.25%).

Highly ordered, ordered and disordered mesoporous carbons were prepared by an organic–organic self-assembly method with different molar ratios of formaldehyde to resorcinol (F/R) under the catalysis of citric acid. The mesoporous carbon synthesized with the F/R ratio of 2 possesses highly ordered pore system and large surface area, while the ones with the F/R ratio of 1 and 3 have an ordered and a disordered wormhole-like mesostructure, respectively. These three kinds of mesoporous carbons were utilized as counter electrode (CE) materials for dye-sensitized solar cells (DSSCs) and the effect of structural mesopore ordering on the photovoltaic performance was investigated. The cell assembled with highly ordered mesoporous carbon CE showed an excellent energy conversion efficiency of 6.06%, which is comparable to the one with Pt CE (6.29%), whereas ordered mesoporous carbon and disordered mesoporous carbon CEs based cells exhibited relatively poor photovoltaic performance at the same testing conditions. The enhanced catalytic capability of highly ordered mesoporous carbon CE is intrinsically attributed to the straight channels of long-range highly ordered 2-D hexagonal mesopores, which accelerates the diffusion of redox species and facilitates the charge-transfer process. The synthesized highly ordered mesoporous carbon with outstanding catalytic activity could be an alternative to replace Pt for high-efficiency DSSC CE.