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Electrochemiluminescence resonance energy transfer (ECL-RET) is a versatile signal transduction strategy widely used in the fabrication of chem/biosensors. However, this technique has not yet been applied in visualized imaging analysis of intracellular species due to the insulating nature of the cell membrane. Here, we construct a ratiometric ECL-RET analytical method for hypochlorite ions (ClO−) by ECL luminophore, with a luminol derivative (L-012) as the donor and a fluorescence probe (fluorescein hydrazide) as the acceptor. L-012 can emit a strong blue ECL signal and fluorescein hydrazide has negligible absorbance and fluorescence signal in the absence of ClO−. Thus, the ECL-RET process is turned off at this time. In the presence of ClO−, however, the closed-loop hydrazide structure in fluorescein hydrazide is opened via specific recognition with ClO−, accompanied with intensified absorbance and fluorescence signal. Thanks to the spectral overlap between the ECL spectrum of L-012 and the absorption spectrum of fluorescein, the ECL-RET effect is gradually recovered with the addition of ClO−. Furthermore, the ECL-RET system has been successfully applied to image intracellular ClO−. Although the insulating nature of the cell itself can generate a shadow ECL pattern in the cellular region, extracellular ECL emission penetrates the cell membrane and excites intracellular fluorescein generated by the reactions between fluorescein hydrazide and ClO−. The cell imaging strategy via ECL-RET circumvents the blocking of the cell membrane and enables assays of intracellular species. The importance of the ECL-RET platform lies in calibrating the fluctuation from the external environment and improving the selectivity by using fluorescent probes. Therefore, this ratiometric ECL sensor has shown broad application prospects in the identification of targets in clinical diagnosis and environmental monitoring. [ABSTRACT FROM AUTHOR]

Developing highly active, durable and economical noble-metal-free electrocatalysts for the hydrogen evolution reaction (HER) plays a crucial role in the future hydrogen economy. Herein, ultrafine cable-like WC/W2C heterojunction nanowires (NWs) covered by few-layer N-doped graphite-like carbon (labeled WC/W2C@C NWs) have been firstly accomplished via a simple two-step pyrolysis treatment of W18O49 NWs precursor, exhibiting tunable phase composition, excellent HER activity, fast kinetic metrics and remarkable stability along the entire pH range. With the optimized phase composition, WC/W2C@C NWs (WC : W2C ≈ 1 : 1.3) display the low overpotentials of 69 mV and 56 mV at the cathodic current density of 10 mA cm−2 and small Tafel slopes of 52 and 59 mV dec−1 in 0.5 M H2SO4 and 1 M KOH, respectively. DFT calculations and experimental results demonstrate that such prominent performance towards the HER was mainly attributed to abundant interfaces between WC and W2C phases in the cable-like heterojunction nanowires which may exert both the high HER activity of W2C and the excellent electrochemical stability and conductivity of WC. Furthermore, the one-dimensional (1D) nanowire morphology and graphite-like carbon shells also promote the conductivity of the whole electrocatalytic material. This work presents a new route to accomplish the morphology control, composition and electronic regulation so as to boost the HER performance of tungsten-carbide-based electrocatalysts, providing new guidance for exploring efficient noble-metal-free electrocatalysts. [ABSTRACT FROM AUTHOR]

During the exploration of highly efficient noble-metal-free electrocatalysts for the hydrogen evolution reaction (HER), a promising and challenging strategy is to fabricate composite nanocatalysts by finely tuning metal and/or nonmetal element components. Herein, we report a new HER electrocatalyst, which is composed of molybdenum phosphide and molybdenum carbide composite nanoparticles (NPs) coated by few-layer N-doped graphitic carbon shells (denoted as MoP/Mo 2 C@C). Such a new combination mode of electrocatalysts is realized by a one-step annealing route with the mixture of a Mo/P-based polyoxometalate (POM) and dicyandiamide. On the basis of this method, the simultaneous phosphorization and carbonization in a nanoscale confined space can be easily achieved by the use of POM as the molecular-element-regulating platform. MoP/Mo 2 C@C exhibits more remarkable HER performance over the whole pH range than those of MoP, Mo 2 C, and the physical mixture of MoP and Mo 2 C. The low overpotentials of 89, 136, and 75 mV were obtained at a current density of 10 mA cm -2 in the media of pH = 0, 7, and 14, respectively. Furthermore, MoP/Mo 2 C@C shows a long-term durability for 14 h over the entire pH range (0-14). Because of the protection of carbon shells, such composite electrocatalyst also possesses better transition-metal tolerance exemplified by Fe 2+ , Co 2+ , and Ni 2+ than that of 20% commercial Pt/C. This work demonstrates the advantage of POM precursors in adjusting the component and properties of nanoscale composite electrocatalysts for HER, which may suggest new options for the fabrication of highly efficient composite electrocatalysts.

Perihilar cholangiocarcinoma, which is a rare primary malignancy, originates from the epithelial cells of the bile duct. Usually invading the periductal tissues and the lymph nodes, perihilar cholangiocarcinoma is commonly diagnosed in the advanced stage of the disease and has a dismal prognosis. Currently, complete hepatectomy is the primary therapy for curing this disease. Perioperative assessment and available surgical procedures can be considered for achieving a negative margin resection, which is associated with long-term survival and better quality of life. For patients with unresectable cholangiocarcinoma, several palliative treatments have been demonstrated to produce a better outcome; and liver transplantation for selected patients with perihilar cholangiocarcinoma is promising and desirable. However, the role of palliative treatments and liver transplantation was controversial and requires more evidence and substantial validity from multiple institutions. In this article, we summarize the data from multiple institutions and discuss the resectability, mortality, morbidity and outcome with different approaches.