Enhanced reduction

Resins are moderately effective in lowering LDL cholesterol but do not lower triglycerides (Table 9-8). Moreover, in patients with elevated triglycerides, the use of a resin may worsen the condition. This may be due to a compensatory increase in HMG-CoA reductase activity and results in an increase in assembly and secretion of VLDL. The increase in HMG-CoA reductase activity can be blocked with a statin, resulting in enhanced reductions in serum lipids (see section on combination therapy). Resins reduce LDL cholesterol from 15% to 30%, with a modest increase in HDL cholesterol (3% to 5%) (Table 9-8). Resins are most often used as adjuncts to statins in patients who require additional lowering of LDL cholesterol. Since these drugs are not absorbed, adverse effects are limited to the gastrointestinal tract (Table 9-9). About 20%... 

Nitrates have been suggested in patients who do not achieve therapeutic goals (heart rate reduction) with P-blocker therapy alone. Trials to evaluate the effects of nitrates (e.g., isosorbide mononitrate) on portal pressure, both alone and in combination with P-blockers, show enhanced reduction of portal pressure however, there is an increase in mortality when nitrates are used alone. Adverse effects are significantly higher in patients treated with the combination of non-selective P-blockers and nitrates as opposed to P-blocker monotherapy.42,43 Unfortunately,... 

Kohno, Y., Hayashi, H., Takenaka, S., Tanaka, T., Funabiki, T. and Yoshida, S. Photo-enhanced reduction of carbon dioxide with hydrogen over Rh/Ti02. Journal of Photochemistry and Photobiology. 1999. A 126,117-123. 

Hung H-M, Hoffmann MR (1998) Kinetics and mechanism of the enhanced reductive degradation of CC14 by elemental iron in the presence of ultrasound. Environ Sci Technol 32(19) 3011—3016... 

The cluster catalyzes hydrogenation (20°C and 3 atm) of dialkyl- and diarylacetylenes to the c/s-olefins via unsaturate routes, likely involving Ni4(CNR)6(RC=CR) and Ni4(CNR)4(RC==CR)3 (391, 392). The acetylenes in the latter complex bridge three nickel centers, and increase of the acetylenic carbon-carbon bond distance is considered to enhance reduction by hydrogen (392, 393). 

On the other hand, in the presence of the contaminant metals the acidities deltas are positive. The enhanced reductive part of the ADV-CPS protocol is probably responsible for this alteration. This observation can be attributed to the limitation of the vanadium deleterious effect on the catalyst s structure, as it is less drastic in its reduced oxidation state. Consequently, all the observations are convergent to the fact that keeping the metals reduced for a certain period of time during the laboratory deactivation procedure seems to be beneficial as far as acidity retention is concerned. 

Finally, it should be pointed out that methods used to study short-lived chemical intermediates in fast thermal reactions may be applicable also to photochemical studies. Radical intermediates, however generated, can be studied by CIDNP ichemically induced dynamic nuclear spin polarization), in which the n.m.r. spectrum of the reaction mixture is recorded during the reaction period. II a substrate is continuously irradiated with ultraviolet/visible light in the cavity of an n.m.r. spectrometer, the resulting n.m.r. spectrum of the substrate/product mixture exhibits intensity variations as compared with the normal spectrum—intensity enhancement, reduction or even reversal (i.e. emissionl. Note that the spectrum involved is not... 

This was confirmed in another system (41) (same technique, but using nitrate) which showed an enhanced reduction rate in alkaline solutions as compared with the neutral pH. 

Enhanced reductive dissolution of Fe and Mn (oxy)(hydr)oxides from hydrocarbons... 

Uto and Sugawara [51] have described a procedure for the determination of nickel in the ng/ml range by differential pulse polarography. The method was used for the formation of water-soluble dithiocarbamate chelates, which were adsorbed onto the mercury electrode. An enhanced reduction current was obtained in an electrolysis solution composed of 0.1 M potassium chloride and 0.015 M ammonium oxalate/0.02 sodium hydroxide buffer in the presence... 

Li Z, Jones HK, Bowman RS, Helferich R. Enhanced reduction of chromate and PCE by pelletized surfactant-modified zeolite/zerovalent iron. Environ Sci Technol 1999 33 4326-4330. 

A model for the direct reduction of iron ore in a moving bed has been developed. The model accounts for the water gas shift equilibrium as well as reduction by the species H2 and CO. Inclusion of this equilibrium has been shown to enhance reduction especially at the high conversions required.Increase of operating temperature can give decreased conversions. 

The enhanced reduction of NO due to the introduction of new oxygen functional groups can... 

For the enhanced reduction of Ni ions by Pd in NaY, it was found that one reduction path includes migration of Ni ions to reduced Pd particles in supercages in parallel paths Ni ions are reduced in Pd -Ni and Pd -Ni pairs (727). TPR results also show that Pd " and PP" ions significantly enhance the reduction of Cu " ions in NaY 73,185). Again, close proximity of Cu and Pt or Pd ions is essential 185). EXAFS shows that small bimetal PtCu or PdCu particles are produced by this coreduction (755,202). 

The enhanced reductive power of Lewis acid/LAH mixtures observed with benzyl substituents is reflected in allyl compounds. Thus allyl methyl ethers are readily demethoxylated with LAH/TiCU (equation 49), with complete rearrangement of the double bond and some (Z)-selectivity. Allyl alcohols are reduced to alkenes with the same reagent or with LAH/AICI3 (equation 50). With both these reagents double bond migration was observed to varying degrees as well as diene formation. Primary allyl alcohols have been reduced to alkenes with titanocene and LAH (equation 51). ... 

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