Mice deficient in the G-protein alpha subunit G(i)alpha(2) spontaneously develop colitis and colon cancer. IL-11 is a pleiotropic cytokine known to protect the intestinal epithelium from injury in animal models of colitis and is produced by subepithelial myofibroblasts in response to inflammatory mediators including TGF-beta, IL-1beta, and PGE(2). Arachidonic acid release and subsequent PGE(2) production is significantly decreased in the colonic mucosa of G(i)alpha(2)-/- mice, and we hypothesized that this would affect mucosal IL-11 production. Mucosal levels of IL-11 were found to be significantly decreased in G(i)alpha(2)-/- mice despite the presence of mild colitis. Primary cultures of G(i)alpha(2)-/- intestinal and colonic myofibroblasts (IMF and CMF, respectively) produced less basal and TGF-beta or IL-1beta-stimulated IL-11 mRNA and protein than wild-type cells. Inhibitors of ERK or p38 MAPK activation dose dependently inhibited IMF and CMF IL-11 production in response to TGF-beta stimulation, whereas 16,16 dimethyl-PGE(2) and prostanoid receptor subtype-selective agonists induced IL-11 production. Treatment of animals with the EP4-specific agonist ONO-AE1-329 resulted in enhanced mucosal levels of IL-11, and increased IL-11 production by ex vivo cultured CMF. Modulation of cAMP levels produced diverging results, with enhancement of TGF-beta-induced IL-11 release in IMF pretreated with 8-Br-cAMP and inhibition in cells treated either with pertussis toxin or the PKA inhibitor H-89. These data suggest a physiological role for prostaglandins, MAPK signaling, and cAMP signaling for the production of myofibroblast-derived IL-11 in the mouse intestinal mucosa.

Part per billion concentrations of acid gases such as SO x and NO x have been detected in both high purity gases and CDA lines. These contaminants can have deleterious effects on a number of high purity applications such as the optics found in lithography equipment steppers, scanners, and inspection tools. In addition, acidic gases have also been shown to reduce the life of masks and reticles, decrease fuel cell output due to catalyst poisoning, and cause hard disk drive crashes due to surface contamination and corrosion. Consequently, acid gas control in these applications has become a critical part of the required filtration system. SO x concentrations are typically used as the baseline for acid gas filter exposure guidelines and performance testing. However, this approach has been shown to provide poor filter life predictions, which has been attributed to the presence of other acidic and organic contaminants that compete with SO x for the available adsorption sites. Equally important, the type of sorbents and methods used to control acid gases can significantly affect the ability to remove SO x . In this work we will compare the performance of various sorbents, structures, and methods for the removal of SO x and NO x .

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The optimal medium in which DUV resists are exposed is becoming increasingly under investigation by lithography tool manufacturers. These medium requirements have created even more design restrictions for effective filtration methods. Traditional airborne molecular contamination control in tracks and exposure tools has focused on the removal of weak bases that poison the resist. Newer concerns, including; the degradation of optics, changes in resist sensitivity, the index of refraction and the demands of tighter geometry's, all contribute to the need for quantification and control of gas-phase contamination within exposure tools. As a result, filter manufacturers are required not only to remove a broader spectrum of contaminants (e.g. organic and acid gases), but to supply removal efficiency data, under a variety of conditions including; variable challenge concentrations, mixed stream contamination, humidity (dew points), flow rates, and temperatures. The paper will address these new concerns focusing on the efficiency effects of relative humidity for various contaminant streams using a variety of filter media. In addition, the removal of hydrophilic compounds such as ammonia and sulfur dioxide when drying an air stream will also be considered. This ongoing study has contributed to the design of a point-of-use air-shower filter used to protect lithography lenses. Preliminary field tests by a major manufacturer indicate that the removal of the specified bases, acids and total organics is below detection limits of <0.1 ppb.