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Abstract

Alterations in the biochemistry of mitochondria have been associated with cell transformation and the acquisition of drug resistance to certain chemotherapeutic agents, suggesting that mitochondria may play a supportive role for the cancer cell phenotype. Mitochondria are multifunctional organelles that contribute to the cellular adenosine triphosphate (ATP) pool and cellular redox balance through the production of reactive oxygen intermediates (ROI). Our laboratory has focused on these mitochondrial functions in the context of cancer cell physiology to evaluate the potential role of mitochondria as controllers of tumour cell proliferation. Low concentrations of ROI have been implicated as messengers in intracellular signal transduction mechanisms; thus an imbalance of ROI production from the mitochondria may support cancer cell growth. In addition, suppression of mitochondrial ATP production can halt cell cycle progression at two energetic checkpoints, suggesting that the use of tumor-selective agents to reduce ATP production may offer a therapeutic target for cancer growth control.

A Methodology to Predict the Effects of Quench Rates on Mechanical Properties of Cast Aluminum Alloys

“…With the calculated quench factor, Q, the strength can be predicted using the following classical quench factor model: [3,9] r À r min…”

“…Based on the original quench factor model shown in Eq. [3], improvements have been made to justify assumptions used for quench factor analysis, including the relationship between strength and solute concentration, minimum strength, and Avrami exponent. [20] The assumption of the linear relationship between strength and retained solute concentration was found to contradict the strengthening theory.…”

“…According to the strengthening theory, Eq. [3] is rewritten as the following improved formula: [20] r À r min…”

“…A variety of mechanical properties have been used for quench factor modeling, including Vickers hardness, [4,5,7,20] Rockwell hardness, [2,10] electrical conductivity, [7,17] yield strength, [3,20,21] and tensile strength. [7] Although many successful predictions were made in the literature, the classical quench factor models were established based on the variation of strength with the retained solute concentration.…”

“…[1] Quench factor analysis has been applied to a wide range of wrought aluminum alloys to predict properties or to optimize industrial quenching procedures. [2][3][4][5] It is now recognized as an important technique for modeling property variation during continuous cooling. In order to use quench factor analysis for property prediction, the kinetic parameters of an aluminum alloy during quenching need to be experimentally estimated and verified.…”