Iron (III) doped titanium dioxide coated dimensionally stable graphite anode electrode for electro-chemical treatment of domestic wastewater.

Availability of clean water is of concern due to pollution and diminishing supply pollution. However, purification is possible depending on the incorporated contaminants. Domestic wastewater contains dissolved organic matter and its remediation can be done by oxidation. The best oxidation can be achieved by electron transfer the same way metabolic processes occur. This study exploited the use of a film of iron (III) doped titanium dioxide applied on an electrode which was found to be effective. Natural light conditions generated electrons that migrated through the electrode leaving behind holes which oxidized the contaminants as the excess electrons were discharged at the cathode after passing through the casted proton exchange membrane (PEM) separating the two half cells of the prepared reactor. This electrochemical method has the advantage in that the organic pollutants are oxidized to carbon dioxide with no secondary pollutants and the inorganic pollutants into insoluble matter. The assembled cell was applied to purify both synthetic and real water samples of green leafy vegetable solution from the kitchen by clarification. The clarification process was monitored by UV-Vis using distilled water as a reference to compare the light that transmitted through a sample. It was observed that the electro-oxidation process took place showing a high potential 105 mV within the first 150 min followed by degradation at a high rate. The oxidation of the organic matter was confirmed by UV-Vis analysis as well as by cyclic voltametric analysis of iron released into the solution of the synthetic samples. The electro chemical treatment of the water was then applied to purify real water samples made from a sample of 4.5 g minced of green vegetables dispersed in one liter of water (4.5 g/l). The green leafy coloured solution was clarified after 154 h of continuous oxidation. The degradation process was confirmed to be independent of intermediates or other species present in solution as it was of first order reaction kinetics. The electrochemical oxidation of organic matter in water using iron (III) doped titanium dioxide coated graphite electrode has potential application on the purification of water.

Antiplasmodial, anti-trypanosomal, anti-leishmanial and cytotoxicity activity of selected Tanzanian medicinal plants.

The antiplasmodial, anti-trypanosomal and anti-leishmanial activity of 25 plant extracts obtained from seven Tanzanian medicinal plants: Annickia (Enantia) kummeriae (Annonaceae), Artemisia annua (Asteraceae), Pseudospondias microcarpa (Anacardiaceae), Drypetes natalensis (Euphorbiaceae), Acridocarpus chloropterus (Malpighiaceae), Maytenus senegalensis (Celastraceae) and Neurautanenia mitis (Papilonaceae), were evaluated in vitro against Plasmodium falciparum K1, Trypanosoma brucei rhodesiense STIB 900 and axenic Leishmania donovani MHOM-ET-67/82. Out of the 25 extracts tested, 17 showed good antiplasmodial activity (IC50 0.04-5.0 microg/ml), 7 exhibited moderate anti-trypanosomal activity (IC50 2.3-2.8 microg/ml), while 5 displayed mild anti-leishmanial activity (IC50 8.8-9.79 microg/ml). A. kummeriae, A. annua, P. microcarpa, D. natalensis, M. senegalensis and N. mitis extracts had good antiplasmodial activity (IC50 0.04-2.1 microg/ml) and selectivity indices (29.2-2,250 microg/ml). The high antiplasmodial, moderate anti-trypanosomal and mild anti-leishmanial activity make these plants good candidates for bioassay-guided isolation of anti-protozoal compounds which could serve as new lead structures for drug development.

Sarcomas of the head and neck at Kenyatta National Hospital.

OBJECTIVE: To determine the pattern of occurrence of sarcomas afflicting the neck and craniofacial region. DESIGN: A retrospective study (1982-1991). SETTING: Cancer Registry, Kenyatta National Hospital, Nairobi, Kenya. METHOD: Examination was performed of the cancer records in the registry over the period 1982 to 1991 inclusive. Histopathological types of the sarcomas were then analysed to indicate the numbers that occurred per year; and also the pattern of occurrence according to age groups, gender and site. RESULTS: Of the 10,897 whole body neoplasms, 985 were sarcomas. Among these sarcomas, 160 (16%) were located in the neck and craniofacial region. The histopathological types of the neoplasms included Kaposi's sarcoma (39%), osteosarcoma (23%), rhabdomyosarcoma (21%), fibrosarcoma (13%), chondrosarcoma (two per cent), malignant fibrous histiocytoma (one per cent) and dermatofibrosarcoma protuberans (one per cent). CONCLUSION: The results of this investigation, in concordance with those of other series worldwide, indicate that the various sarcomas afflicting the neck and craniofacial area are generally rare.