A novel plant toxin, persin, with in vivo activity in the mammary gland, induces Bim-dependent apoptosis in human breast cancer cells

Phytochemicals have provided an abundant and effective source of therapeutics for the treatment of cancer. Here we describe the characterization of a novel plant toxin, persin, with in vivo activity in the mammary gland and a p53-, estrogen receptor-, and Bcl-2-independent mode of action. Persin was previously identified from avocado leaves as the toxic principle responsible for mammary gland-specific necrosis and apoptosis in lactating livestock. Here we used a lactating mouse model to confirm that persin has a similar cytotoxicity for the lactating mammary epithelium. Further in vitro studies in a panel of human breast cancer cell lines show that persin selectively induces a G(2)-M cell cycle arrest and caspase-dependent apoptosis in sensitive cells. The latter is dependent on expression of the BH3-only protein Bim. Bim is a sensor of cytoskeletal integrity, and there is evidence that unique structure of the compound, persin could represent a novel class of microtubule-targeting agent with potential specificity for breast cancers.

Effect of temperature and free ammonia on nitrification and nitrite accumulation in landfill leachate and analysis of its nitrifying bacterial community by FISH

The cause of seasonal failure of a nitrifying municipal landfill leachate treatment plant utilizing a fixed biofilm was investigated by wastewater analyses and batch respirometric tests at every treatment stage. Nitrification of the leachate treatment plant was severely affected by the seasonal temperature variation. High free ammonia (NH3-N) inhibited not only nitrite oxidizing bacteria (NOB) but also ammonia oxidizing bacteria (AOB). In addition, high pH also increased free ammonia concentration to inhibit nitrifying activity especially when the NH4-N level was high. The effects of temperature and free ammonia of landfill leachate on nitrification and nitrite accumulation were investigated with a semi-pilot scale biofilm airlift reactor. Nitrification rate of landfill leachate increased with temperature when free ammonia in the reactor was below the inhibition level for nitrifiers. Leachate was completely nitrified up to a load of 1.5 kg NH4-N m(-3) d(-1) at 28 degrees C. The activity of NOB was inhibited by NH3-N resulting in accumulation of nitrite. NOB activity decreased more than 50% at 0.7 mg NH3-N L-1. Fluorescence in situ hybridization (FISH) was carried out to analyze the population of AOB and NOB in the nitrite accumulating nitrifying biofilm. NOB were located close to AOB by forming small clusters. A significant fraction of AOB identified by probe Nso1225 specifically also hybridized with the Nitrosonlonas specific probe Nsm156. The main NOB were Nitrobacter and Nitrospira which were present in almost equal amounts in the biofilm as identified by simultaneous hybridization with Nitrobacter specific probe Nit3 and Nitrospira specific probe Ntspa662. (c) 2005 Elsevier Ltd. All rights reserved.

Characterization of sugar cane waste biomass derived chars from pressurized gasification

There is interest in the use of sugar cane waste biomass for electricity cogeneration, by integrated gasification combined cycle (IGCC) processes. This paper describes one aspect of an overall investigation into the reactivity of cane wastes under pressurized IGGC conditions, for input into process design. There is currently a gap in understanding the morphological transformations experienced by cane waste biomass undergoing conversion to char during pressurized gasification, which is addressed by this work. Char residuals remaining after pressurized pyrolysis and carbon dioxide gasification were analysed by optical microscope, nitrogen (BET) adsorption analysis, SEM/EDS, TEM/EDS and XPS techniques. The amorphous cane plant silica structures were found to remain physically intact during entrained flow gasification, but chemically altered in the presence of other inorganic species. The resulting crystalline silicates were mesoporous (with surface areas of the order of 20 m(2) g(-1)) and contributed to much of the otherwise limited pore volume present in the residual chars. Coke deposition and intimate blending of the carbonaceous and inorganic species was identified. Progressive sintering of the silicates appeared to trap coke deposits in the pore network. As a result ash residuals showed significant organic contents, even after extensive additional oxidation in air. The implications of the findings are that full conversion of cane trash materials under pressurized IGCC conditions may be significantly hampered by the silica structures inherent in these biomass materials and that further research of the contributing phenomena is recommended.

Wills' mineral processing technology: an introduction to the practical aspects of ore treatment and mineral recovery

"Wills' Mineral Processing Technology" provides practising engineers and students of mineral processing, metallurgy and mining with a review of all of the common ore-processing techniques utilized in modern processing installations. Now in its Seventh Edition, this renowned book is a standard reference for the mineral processing industry. Chapters deal with each of the major processing techniques, and coverage includes the latest technical developments in the processing of increasingly complex refractory ores, new equipment and process routes. This new edition has been prepared by the prestigious J K Minerals Research Centre of Australia, which contributes its world-class expertise and ensures that this will continue to be the book of choice for professionals and students in this field. This latest edition highlights the developments and the challenges facing the mineral processor, particularly with regard to the environmental problems posed in improving the efficiency of the existing processes and also in dealing with the waste created. The work is fully indexed and referenced. -The classic mineral processing text, revised and updated by a prestigious new team -Provides a clear exposition of the principles and practice of mineral processing, with examples taken from practice -Covers the latest technological developments and highlights the challenges facing the mineral processor -New sections on environmental problems, improving the efficiency of existing processes and dealing with waste.

Using the floatability characterisation test rig for industrial flotation plant design

Industrial flotation plant design is a complex process involving many aspects, one of which is the use of pilot-scale plants to test industrial plant flow sheets. Once test work on a pilot-scale has been performed, scale-up of these results to the full-scale plant must be performed. This paper describes scale-up test work performed on the Floatability Characterisation Test Rig (FCTR). The FCTR is a self-contained, highly instrumented mobile pilot plant designed to determine flotation model parameters and to develop and validate flotation plant modelling, scale-up and simulation methodologies.

Cellulosic waste degradation by rumen-enhanced anaerobic digestion

Anaerobic digestion of lignocellulosic material is carried out effectively in many natural microbial ecosystems including the rumen. A rumen-enhanced anaerobic sequencing batch reactor was used to investigate cellulose degradation to give analysis of overall process stoichiometry and rates of hydrolysis. The reactor achieved VFA production rates of 207-236 mg COD/L/h at a loading rate of 10 g/L/d. Overloading of the reactor resulted in elevated production of propionic acid, and on occasion, the presence of succinic acid. With improvements in mixing and solids wasting, the anaerobic sequencing batch reactor system could enable full-scale application of the process for treatment of cellulosic waste material.