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Nearly all solid granular foods and powdered ingredients, such as sugar, flour, grain, spices, starch, and powdered flavors, have the capacity to sustain a combustion. This may result often in dust fires, originating from dust layers and heaps, and sometimes also in violent explosions, when the dust is suspended and a cloud is formed. Many factors affect the explosion violence or the ignition sensitivity of a dust cloud: these can be related to physical properties of the solid material (particle size, moisture content, minimum ignition temperature, etc.) and to the geometry of the system involved in the explosion (closed vessels, long pipes, degree of turbulence, etc.). While the conditions to have an explosion occur rarely in processing buildings, hazardous dust clouds regularly form during bin filling, powder conveying, or dust collection. The scope of this paper is to review a selection of incidents occurred in the past involving solid food materials and analyze them against the current best industrial practices regarding explosion prevention and protection. Particular attention will be given to the analysis of potential ignition sources and their effectiveness in igniting the flammable dust atmosphere. A selection of “lessons learnt” will also be derived from the analysis of the incidents. Lastly, the paper shall discuss the most recent trends of combustible dust fires and explosions among other industry sectors (pharmaceutical, wood processing, chemical, energy production), to gain insights about potential areas of improvement to advance in people and plant safety. [ABSTRACT FROM AUTHOR]

The discovery of the anti-proliferative activity of nelfinavir in HIV-free models has encouraged its investigation as anticancer drug. Although the molecular mechanism by which nelfinavir exerts antitumor activity is still unknown, its effects have been related to Akt inhibition. Here we tested the effects of nelfinavir on cell proliferation, viability and death in two human breast cancer cell lines and in human normal primary breast cells. To identify the mechanism of action of nelfinavir in breast cancer, we evaluated the involvement of the Akt pathway as well as the effects of nelfinavir on reactive oxygen species (ROS) production and ROS-related enzymes activities. Nelfinavir reduced breast cancer cell viability by inducing apoptosis and necrosis, without affecting primary normal breast cells. The antitumor activity of nelfinavir was related to alterations of the cell redox state, coupled with an increase of intracellular ROS production limited to cancer cells. Nelfinavir treated tumor cells also displayed a downregulation of the Akt pathway due to disruption of the Akt-HSP90 complex, and subsequent degradation of Akt. These effects resulted to be ROS dependent, suggesting that ROS production is the primary step of nelfinavir anticancer activity. The analysis of ROS-producers and ROS-detoxifying enzymes revealed that nelfinavir-mediated ROS production was strictly linked to flavoenzymes activation. We demonstrated that ROS enhancement represents the main molecular mechanism required to induce cell death by nelfinavir in breast cancer cells, thus supporting the development of new and more potent oxidizing molecules for breast cancer therapy. [ABSTRACT FROM AUTHOR]