Silent Generation

Ozone can be generated by a variety of methods, the most common of which involves the dissociation of molecular oxygen electrically (silent discharge) or photochemicaHy (uv). The short-Hved oxygen atoms (lifetime s) react rapidly with oxygen molecules to form ozone. The widely employed technique... 

Commercial production and utilization of ozone by silent electric discharge consists of five basic unit operations gas preparation, electrical power supply, ozone generation, contacting (ie, ozone dissolution in water), and destmction of ozone in contactor off-gases (Fig. 1). 

Ozone. Ozone generators are based on uv or silent discharge. Although uv ozone generators are marketed, they are not effective for treating... 

During differentiation of T- or B-lymphocytes antigen recqrtors are generated which react to self or autoantigens. These are generally eliminated by the mechanisms of central tolerance or kept silent by the mechanisms of peripheral tolerance ( autoimmune disease). 

Proteases are enzymes that break peptide bonds in proteins. As such they lend themselves to a variety of homogeneous assay techniques. Most employ labeling both ends of the substrate with a different tag, and looking for the appearance (disappearance) of the signal generated in the intact substrate (product). As an example, for a fluorescence quench assay, the N-terminal of a peptide is labeled with DNP and the C-terminal with MCA. As such, the peptide is fluorescently silent since the fluorescence from DNP is quenched by absorption by the MCA. Another very popular donor/acceptor pair is EDANS 5-[(2-aminoethyl)amino] naphthalene-1-sulfonic acid and DABCYL 4-(4-dimethylaminophenylazo)benzoic acid) (a sulfonyl derivative (DABSYL) [27], Upon peptide cleavage, the two products diffuse, and due to a lack of proximity, the fluorescence increases. 

Liu L, Graham G, Hu T, et al. The silent chemokine receptor D6 is required for generating T cell responses that mediate experimental autoimmune encephalomyelitis. J Immunol 2006 177(1) 17-21. 

Results of a chemical activation induced by ultrasound have been reported by Nakamura et al. in the initiation of radical chain reactions with tin radicals [59]. When an aerated solution of R3SnH and an olefin is sonicated at low temperatures (0 to 10 °C), hydroxystannation of the double bond occurs and not the conventional hydrostannation achieved under silent conditions (Scheme 3.10). This point evidences the differences between radical sonochemistry and the classical free radical chemistry. The result was interpreted on the basis of the generation of tin and peroxy radicals in the region of hot cavities, which then undergo synthetic reactions in the bulk liquid phase. These findings also enable the sonochemical synthesis of alkyl hydroperoxides by aerobic reductive oxygenation of alkyl halides [60], and the aerobic catalytic conversion of alkyl halides into alcohols by trialkyltin halides [61]. 

FIGURE 1.5 Silent zone in lee of a hedgerow. Wind-tunnel visualization of air movement over a windbreak, such as a hedgerow, with aid of a bubble generator. Wildlife seek such zones for protection from wind, but information flow through air can be reduced there. (From Moen, 1973.)... 

Adrenal medulla. On the one hand, release of epinephrine elicits cardiovascular effects, such as increases in heart rate und peripheral vascular resistance. On the other, it evokes metabolic responses, such as glycogenolysis and li-polysis, that generate energy-rich substrates. The sensation of hunger is suppressed. The metabolic state corresponds to that associated with physical exercise - silent stress . 

Tanner, K.G., Landry, J., Sternglanz, R. and Denu, J.M. (2000) Silent information regulator 2 family of NAD- dependent histone/protein deacetylases generates a unique product, 1-O-acetyl-ADP-ribose. Proceedings of the National Academy of Sciences of the United States of America, 97, 14178-14182. 

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