Field Effect versus Driving Force: Charge Generation in Small-Molecule Organic Solar Cells

Efficient charge generation in organic semiconductors usually requires an interface with an energetic gradient between an electron donor and an electron acceptor in order to dissociate the photogenerated excitons. However, single-component organic solar cells based on chloroboron subnaphthalocyanine (SubNc) have been reported to provide considerable photocurrents despite the absence of an energy gradient at the interface with an acceptor. In this work, it is shown that this is not due to direct free carrier generation upon illumination of SubNc, but due to a field-assisted exciton dissociation mechanism specific to the device configuration. Subsequently, the implications of this effect in bilayer organic solar cells with SubNc as the donor are demonstrated, showing that the external and internal quantum efficiencies in such cells are independent of the donor-acceptor interface energetics. This previously unexplored mechanism results in efficient photocurrent generation even though the driving force is minimized and the open-circuit voltage is maximized

Transcatheter arterial embolization of internal mammary artery in a hepatocellular carcinoma with abdominal wall invasion

WOS: 000076237900012PubMed ID: 9788022Transcatheter arterial embolization (TAE) is alternatively employed to surgical resection in the management of hepatocellular carcinoma (HCC). TAE through the hepatic artery is sometimes insufficient since the blood supply to HCC may be from the collateral vessels as well. We report a case of HCC with abdominal wall invasion who underwent TAE through the right internal mammary artery after insufficient embolization of the tumor through the hepatic artery. (C) 1998 Elsevier Science Ireland Ltd. All rights reserved

Living donor liver transplantation from hepatitis B core antibody positive donors.

American Transplant Congress -- MAY 14-19, 2004 -- Boston, MAWOS: 000221322500496Amer Soc Transplant Surg, Amer Soc Transplanta