Efficient organic photovoltaic cells on a single layer graphene transparent conductive electrode using MoOx as an interfacial layer.

The large surface roughness, low work function and high cost of transparent electrodes using multilayer graphene films can limit their application in organic photovoltaic (OPV) cells. Here, we develop single layer graphene (SLG) films as transparent anodes for OPV cells that contain light-absorbing layers comprised of the evaporable molecular organic semiconductor materials, zinc phthalocyanine (ZnPc)/fullerene (C60), as well as a molybdenum oxide (MoOx) interfacial layer. In addition to an increase in the optical transmittance, the SLG anodes had a significant decrease in surface roughness compared to two and four layer graphene (TLG and FLG) anodes fabricated by multiple transfer and stacking of SLGs. Importantly, the introduction of a MoOx interfacial layer not only reduced the energy barrier between the graphene anode and the active layer, but also decreased the resistance of the SLG by nearly ten times. The OPV cells with the structure of polyethylene terephthalate/SLG/MoOx/CuI/ZnPc/C60/bathocuproine/Al were flexible, and had a power conversion efficiency of up to 0.84%, which was only 17.6% lower than the devices with an equivalent structure but prepared on commercial indium tin oxide anodes. Furthermore, the devices with the SLG anode were 50% and 86.7% higher in efficiency than the cells with the TLG and FLG anodes. These results show the potential of SLG electrodes for flexible and wearable OPV cells as well as other organic optoelectronic devices.

Graphene oxide/graphene vertical heterostructure electrodes for highly efficient and flexible organic light emitting diodes.

The relatively high sheet resistance, low work function and poor compatibility with hole injection layers (HILs) seriously limit the applications of graphene as transparent conductive electrodes (TCEs) for organic light emitting diodes (OLEDs). Here, a graphene oxide/graphene (GO/G) vertical heterostructure is developed as TCEs for high-performance OLEDs, by directly oxidizing the top layer of three-layer graphene films with ozone treatment. Such GO/G heterostructure electrodes show greatly improved optical transmittance, a large work function, high stability, and good compatibility with HIL materials (MoO3 in this work). Moreover, the conductivity of the heterostructure is not sacrificed compared to the pristine three-layer graphene electrodes, but is significantly higher than that of pristine two-layer graphene films. In addition to high flexibility, OLEDs with different emission colors based on the GO/G heterostructure TCEs show much better performance than those based on indium tin oxide (ITO) anodes. Green OLEDs with GO/G heterostructure electrodes have the maximum current efficiency and power efficiency, as high as 82.0 cd A(-1) and 98.2 lm W(-1), respectively, which are 36.7% (14.8%) and 59.2% (15.0%) higher than those with pristine graphene (ITO) anodes. These findings open up the possibility of using graphene for next generation high-performance flexible and wearable optoelectronics with high stability.

Transcatheter arterial embolization of acute gastrointestinal tumor hemorrhage with Onyx.

BACKGROUND: Endovascular embolization has been used to control gastrointestinal tumor bleeding. Lots of embolic agents have been applied in embolization, but liquid embolic materials such as Onyx have been rarely used because of concerns about severe ischemic complications. AIM: To evaluate the clinical efficacy and safety of transcatheter arterial embolization (TAE) with Onyx for acute gastrointestinal tumor hemorrhage. MATERIALS AND METHODS: Between September 2011 and July 2013, nine patients were diagnosed as acute gastrointestinal tumor hemorrhage by clinical feature and imaging examination. The angiographic findings were extravasation of contrast media in the five patients. The site of hemorrhage included upper gastrointestinal bleeding in seven cases and lower gastrointestinal bleeding in two cases. TAE was performed using Onyx in all the patients, and the blood pressure and heart rate were monitored, the angiographic and clinical success rate, recurrent bleeding rate, procedure related complications and clinical outcomes were evaluated after therapy. The clinical parameters and embolization data were studied retrospectively. RESULTS: All the patients (100%) who underwent TAE with Onyx achieved complete hemostasis without rebleeding and the patients were discharged after clinical improvement without a second surgery. No one of the patients expired during the hospital course. All the patients were discharged after clinical improvement without a second surgery. Postembolization bowel ischemia or necrosis was not observed in any of the patients who received TAE with Onyx. CONCLUSIONS: TAE with Onyx is a highly effective and safe treatment modality for acute gastrointestinal tumor hemorrhage, even with pre-existing coagulopathy.

Loop-mediated isothermal amplification for rapid detection of acute viral necrobiotic virus in scallop Chlamys farreri.

Loop-mediated isothermal amplification (LAMP) assay for rapid and sensitive detection of Acute viral necrobiotic virus (AVNV) in scallop Chlamys farreri was developed and evaluated. Four primers recognizing six targets on distinct AVNV DNA sequences were designed and the LAMP reaction was carried out in a water bath. Reaction temperature and time were optimized at 64 degrees C for 60 mins and LAMP products were detected using agarose gel electrophoresis and visual assessment. Confirmation of the expected LAMP products was performed with MboI restriction enzyme analysis. The detection limit of LAMP assay was as low as 1 fg AVNV DNA and accordingly, this assay was 100 times more sensitive than conventional PCR technique. A comparative evaluation of 20 samples using the LAMP and PCR assays revealed a complete accord in positivity or negativity for AVNV. These results indicate that the LAMP assay is simple, sensitive, specific, and has a great potential for detection of AVNV in the laboratory and field.