Kinetic studies on the adsorption of Cd2+, Cu2+ and Zn2+ ions from aqueous solutions by cassava (Manihot sculenta Cranz) tuber bark waste.

The kinetics of Cd2+, Cu2+ and Zn2+ adsorption onto pure and thioglycolic acid treated cassava tuber bark wastes (CTBW) were investigated using a batch sorption technique at 30 degrees C. Kinetic data suggested that the adsorption process was exothermic, the rate limiting sorption step was physisorption and adsorption rates could be best described by a pseudo-second order model. Rate coefficients were determined to range between 1.39x10(-2)min(-1) and 5.94x10(-2)min(-1), 1.46x10(-3)min(-1) and 5.76x10(-3)min(-1) and 0.69x10(-3)min(-1) and 5.8x10(-3)min(-1) for Cd2+, Cu2+ and Zn2+, respectively. The results from these studies indicated that the sorption process is fast and stable. The adsorption equilibria were evaluated using the Langmuir equation and the monolayer sorption capacity was found to range between 5.88-26.3mg/g, 33.3-90.9 mg/g and 22.2-83.3mg/g for Cd2+, Cu2+ and Zn2+, respectively. Negative values of DeltaG(ads)(0) indicated that the adsorption process was spontaneous and exothermic in nature.

Ruptured heterotopic pregnancy: a case report and brief review of the literature.

BACKGROUND: Ruptured heterotopic pregnancy as a cause of acute abdomen is not commonly seen. The aim of this case report is to stress the importance of sonographic examination of the pelvic region in all symptomatic patients in the first trimester of pregnancy. METHOD: The case report of a 23-year-old female with a ruptured heterotopic pregnancy is presented together with a brief review of the literature. RESULTS: A 23 year old female presented with signs and symptoms of an acute abdomen. She gave a history of 8 weeks amenorrhoea. Ultrasound scan (USS) showed an intra uterine pregnancy coexisting with a tubal pregnancy. CONCLUSION: All patients with symptoms of abdominal pain and history of amenorrhoea should have a sonographic examination of the pelvic region.

Distribution and partitioning of trace metals in sediments of the lower reaches of the New Calabar River, Port Harcourt, Nigeria.

The distribution of trace metals in sediments of the lower reaches of the New Calabar River, Nigeria was evaluated together with the partitioning of their chemical species between five geochemical phases. Samplings were made in five zones at the lower reaches of the New Calaber River. All the trace metals were determined by AAS after selective chemical extractions and concentrations given in microg gm(-1) (dry weight basis). The average total concentrations found for trace metals in the sediment were ( mean +/- rsd.) Pb: 41.6 +/- 0.29, Zn: 31.60 +/- 0.42, Cd: 12.80 +/- 0.92, Co: 92 +/- 0.25, Cu: 25.5 +/- 0.65 and Ni: 3.2 +/- 0.25. Maxima and minima concentrations are inconsistent with previous studies in other rivers of this region. Spatial distribution revealed that the sources of trace metals into the river appeared to be of non-point. Five contamination indices were applied in studying the partitioning of the trace metals in the sediment. These indices provided bases for ascertaining the potential environmental risk of trace metals in the river system. The results denote high partition levels in the more mobile and more dangerous phases.

Constituents of West African medicinal plants. XXX. Tridictyophylline, a new morphinan alkaloid from Triclisia dictyophylla.

Triclisia dictyophylla Diels (Menispermaceae) is a woody climber indigenous to West Africa which has been used natively as a medicinal in the treatment of several ailments. Chromatography of an extract of the whole plant afforded tridictophylline (3), a new morphinan alkaloid whose structure was established by a consideration of spectral data and confirmed by x-ray crystallographic analysis. The bisbenzylisoquinoline dibenzodioxin alkaloids cocsuline (1) and trigilletimine (2) were also isolated from the same extract.