Comparative reduction

The original steam generators were simple pressure vessels that were prone to caiasirophic failures and loss of life. Due to better boiler design, tube-fired boilers, and boiler inspections, the incidence of catastrophic failure is now to a rare event (about once every 100,000 vessel-years). In Great Britain in 1866, there were 74 steam boiler explosions causing 77 deaths. This was reduced to 17 explo.sions and 8 deaths in 1900 as a result of inspections performed by the Manchester Steam User Association. In the United States, the American Society of Mechanical Engineers established the ASME Pressure Ves.sel Codes with comparable reductions. 

In contrast, following a treatment regimen of 20 mg/kg MDMA, there were no significant differences in the density of [3H]mazindol-labeled norepinephrine (NE) uptake sites (fmol/mg protein) in the frontal cerebral cortex between saline-treated (159 17) and MDMA-treated (152 5) animals. With respect to the dose of MDMA, serotonin levels appeared to be more readily decreased (45 percent reduction at 5 mg/kg), while comparable reductions in 5-HlAA levels and serotonin uptake sites were noted only at 10 or 20 mg/kg MDMA. This apparent discrepancy among the three serotonergic markers measured in the present study may relate to effects of lower doses of MDMA on synthetic enzyme activity (i.e., TPH), whereas the effects of higher doses of MDMA in reducing all three markers may relate in part to effects on TPH activity and in part to destruction of serotonin neurons as evidenced by decreases in serotonin uptake sites. 

The range of SCS values (P-CH3O to p-NC>2) for nitrostyrenes is about 13 ppm. The correlation of the 170 chemical shift data for nitrostyrenes with that for nitrobenzenes57 gives a slope of 0.58 (Figure 3), which indicates that a comparable reduction in substituent effects results when the nitro function is separated from a p-substituted phenyl group by a carbon-carbon double bond. 

The dispersity or homogeneity of the reductant in a reaction system sometimes plays a decisive role. It is also important for synthetic practice. Crandall and Mualla (1986) compared reduction of 7-methylocta-5,6-diene-2-one [H3C-C(CH3)=C=CH-CH2-CH2-C(0)-CH3] in THF by the action of naphthalene-sodium, on the one hand and, by sonically activated sodium on the other. In both the cases, one-electron transfer yields the anion-radical salt of the allenic ketone with sodium. However, only in the case of sonicated sodium is this salt stabilized, eventually giving H3C-C(CH3)=C=CH-CH2-CH2-C(0H)-CH3 along with cyclic products (l-methyl-2-isopropylidene cyclopentanol and l-methyl-2-isopropylcyclopent-2-enol). If naphthalene-sodium is used, only the cyclic alcohols are obtained as mentioned earlier. 

Kitts DD, Popovich G, Hu C (2007) Characterizing the mechanism for ginsenoside-induced cytotoxicity in cultured leukemia (THP-1) cells. Can J Physiol Pharmacol 85 1173-1183 Dascalu A, Sievenpiper JL, Jenkins AL, et al (2007) Five batches representative of Ontario-grown American ginseng root produce comparable reductions of postprandial glycemia in healthy individuals. Can J Physiol Pharmacol 85 856-864... 

Gomila, M., Solis, J. J., David, Z., Ramon, C., and Lalucat, J. (2008). Comparative reductions of bacterial indicators, bacteriophage-infecting enteric bacteria and enteroviruses in waste-water tertiary treatments by lagooning and UV-radiation. Water Sci. Technol. 58, 2223-2233. 

One way to circumvent such (unjustified) labeling is to try to prove a causal relationship between the maternal effects and those in offspring, thus trying to show that the latter ones are unspecific secondary consequences of the former ones. So for the sound interpretation of study results it is important to find a good balance between maternal and fetal effects. For example, if a 10% reduction in maternal net weight gain is accompanied by a comparable reduction in fetal weight, then this puts the fetal effects in the correct perspective and would not lead the experimenter to conclude that the compound is a (specific) developmental toxicant. On the other hand if in the same situation the number of fetal anomalies (in particular malformations) is increased, then this could most unlikely be explained as a consequence of maternal toxicity. 

The reduction to the divalent state involves samarium, europium, and ytterbium. In 1906 C. Matignon and E. Gazes obtained samarium(II) chloride by reducing the trichloride with hydrogen. In 1911, G. Urbain and F. Bourion prepared europium(II) chloride by a comparable reduction involving gydrogen, and in 1929 ytterbium(II) chloride was similarly obtained by W. Klemm and W. Schuth. 

Gasteiger S, Eggert G (2004) How to compare reduction methods for corroded silver finds. Metal 2001 Proceedings of the International Conference on Metals Conservation, Santiago, Chile, 2-6 April 2001, Western Australian Museum 320-324. 

Most studies comparing imipramine and alprazolam indicate that both drugs produce a comparable reduction of symptoms, although onset of action is considerably slower with a TCA, requiring 2 weeks to as long as 12 weeks (21,24, 26, 37, 85, 92). 

Table n. Comparative reduction patterns in aqueous media for 4-aminopyrimidine and related compounds ... 

In practice, much higher flow rates and somewhat larger resin particles were usually used. Flow velocities were typically in the range of 5 to 25 ml cm 2 min 1 cm min 1 for elution and up to 50 cm min 1 for loading. In contrast, conventional ion exchange separations of trivalent actinides commonly used 0.1 to 0.2 cm min 1. Thus, the time required for the separation was reduced by factors of 10 to 100, with a comparable reduction in radiation damage. 

Lavoisier answered unequivocally in the affirmative, drawing on the comparative reductions carried out with and without charcoal. The air obtained with charcoal displayed all the properties of fixed air. The air obtained without charcoal reacted negatively to each of the standard tests for fixed air, an outcome he supposedly recognized with great surprise. Furthermore, candles burned more brightly in this new air, which also supported respiration better. All this convinced him that this air was not only common air, but that it was even more respirable, more combustible, and consequently more pure even than the air in which we live. In other words, the air contained in calces was an exceedingly pure portion of the atmospheric air. The combination of this air with charcoal produced fixed air, normally encountered in the reduction of calces over charcoal. By now, Lavoisier had all the elements of his new theory of combustion and calcination, except the precise identity of this exceedingly pure portion of common air. 

Olefinic acids have been reduced to saturated acids in excellent yields by a variety of methods. Catalytic hydrogenation at room temperature over platinum oxide catalyst is described for 4-phenyl-3-pentenoic acid (98%). Behenic and undecanoic acids are prepared from the naturally occurring erucic and undecylenic acids with this catalyst. New and "aged platinum oxide catalysts have been compared, Reduction by nickel-aluminum alloy has been preferred to catalytic hydrogenation over platinum catalyst in the preparation of y-isopropylvaleric acid. ... 

The reduced column volume and hence the comparable reduction in detector and... 

Geselowitz 183) has argued similarly, although using a far simpler force field, that the relative effect of ligand strain on the two oxidation states can be estimated and used to predict comparative reduction potentials. 

A series of papers by Gould and collaborators compares reductions by U +, Cr +, Eu +, V +, and [RutNHslel. They establish that reduces both by outer- and inner-sphere mechanisms. Using [Coens, [CoCNHsle] , and [CoCNHslsR] as oxidants (R = imidazole, pyrazole, pyr, or DMF), an outer-sphere mechanism was involved. The log- values for as reductant were linearly related to the analogous values for Cr +, Eu +, and [RuCNHsle], agreeing with the Mar-... 

Between the two phosphate supports MgAAP is less interactive than AAP under comparable reduction treatment. This difference could be due to the slightly larger particle size of Ni on MgAAP, or a lower availability of phosphorous in the former support. Our present data cannot differentiate these possibilities. The important point is that a lowering in Curie temperature can also be induced in MgAAP, indicating a similar mechanism of interaction in the phosphate family. 

A striking feature of the results with y-rays, particularly in comparison with later experiments on other reactions, was the long irradiation required, perhaps 70 days for a reduction of the activity to one-half its original value (9). In contrast, the reactor irradiations which produced comparable reduction in activity were no more than 5 minutes at 4 x 10i fast neutrons cm sec i (iI5). A rough estimate of the dose rates... 

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