Contrast-enhanced ct and angiographic findings in hepatic perivascular epithelioid cell tumor.

We report a case of hepatic perivascular epithelioid cell tumor (PEComa) in a woman who was not a carrier of viral hepatitis and had a normal alpha-fetoprotein (AFP) level. CT scan showed a well-enhanced mass in the arterial-phase followed by early washout in the portal venous-phase in the lateral segment of the liver. Angiography revealed a hypervascular tumor in the liver with rapid washout of the contrast. If a hepatic tumor is found in a female patient with normal AFP level who is not a carrier of hepatitis and is free of alcoholic liver cirrhosis, tissue biopsy should precede treatment to avoid misdiagnosis of liver PEComa as hepatocellular carcinoma.

Effect of pH, ionic strength and fulvic acid on the sorption and desorption of cobalt to bentonite.

Humic substances and bentonite have attracted great interest in radioactive waste management. Here the sorption of cobalt on bentonite in the presence and absence of fulvic acid (FA) under ambient conditions was studied. The effects of pH, ionic strength, FA and solution concentrations on cobalt sorption to bentonite were also investigated using batch techniques. The results indicate that the sorption of cobalt is strongly dependent on pH and is independent of ionic strength under our experimental conditions. Surface complexation is considered the main mechanism of cobalt sorption to bentonite. In the presence of FA, little effect of FA on cobalt sorption was found at pH<6; a positive effect of FA on cobalt sorption was found for pH 6-8; and a negative effect of FA on cobalt sorption was found at pH>8. The addition sequences of FA/Co(2+) to the bentonite suspension on the sorption of cobalt to FA-coated bentonite were also studied. The results indicated that the sorption is not influenced by the addition sequences. Some possible mechanisms are discussed.