Mechanisms of enhancement

There are two principal mechanisms of enhanced oil recovery increasing volumetric sweep efficiency of the injected fluid and increasing oil displacement efficiency by the injected fluid. In both, chemicals are used to modify the properties of an injected fluid whether water, steam, a miscible gas such as CO2 or natural gas, or an immiscible gas, usually nitrogen. Poor reservoir volumetric sweep efficiency is the greatest obstacle to increasing oil recovery (9). 

Joseph EK, Chen X et al (2004) Novel mechanism of enhanced nociception in a model of AIDS therapy-induced painful peripheral neuropathy in the rat. Pain 107(1-2) 147-158 Jubelt B, Berger JR (2001) Does viral disease underlie ALS Lessons from the AIDS pandemic. Neurology 57(6) 945-946... 

A third way to increase both the active surface area and the number of oxygenated species at the electrode surface is to prepare alloy particles or deposits and then to dissolve the non-noble metal component. This technique, which is similar to that used to prepare Raney-type catalysts, yields very high surface area electrodes and hence some improvements in the electrocatalytic activities compared with those of pure platinum. However, it is always difficult to be sure whether the mechanism of enhancment of the activities is due to this effect or the possible presence of remaining traces of the dissolved metal. Results with PtyCr and PtSFe were encouraging, although the effect of iron is still under discussion. From studies in a recent work on the behavior of R-Fe particles for methanol electrooxidation, it was concluded that the electrocatalytic effect is due to the Fe alloyed to platinum. ... 

Finally, we briefly discuss the mechanism of enhanced specific ORR activities (ki p) at the Pt skin layer on the alloys. The Tafel slope in the high current density region at the Pt skin layer was found to be 120mV/decade [Toda et al., 1999 Wakabayashi et al., 2005b], indicating that the enhancement of ORR activities at... 

P Schmeidlin-Ren, DJ Edwards, ME Fitzsimmons, K He, KS Lown, PM Woster, A Rahman, KE Thummel, JM Fisher, PF Hollenberg, PB Watkins. Mechanisms of enhanced oral availability of CYP3A4 substrates by grapefruit constituents decreased enterocyte CYP3A4 concentration and mechanism-based inactivation by furanocoumarins. Drug Metab Dispos 25 1228-1233, 1997. 

Tuziuti T, Yasui K, Lee J, Kozuka T, Towata A, Iida Y (2008) Mechanism of enhancement of sonochemical-reaction efficiency by pulsed ultrasound. J Phys Chem A 112 4875—4878... 

K. S., Woster, P. M., Rahman, A., Thummei, K. E., Fisher, J., Hollenberg, P. F., Watkins, P. B., Mechanisms of enhanced oral availability of CYP3A4 substrates by grapefruit juice constituents, Drug Metab. Disp. 1997, 25, 1228-1233. 

Cox DH, Aid rich RW 2000 Role of the /) 1 subunit in large-conductance Ca2+-activated K+ channel gating energetics mechanisms of enhanced Ca2+ sensitivity. J Gen Physiol 116 411-432... 

Blodinger, J. (1982). Formulation of Veterinary Dosage Forms. Marcel Dekker, New York. Borowitz, J.L., Moore, P.F., Yim, G.K.W. and Miya, T.S. (1971). Mechanism of enhanced drug effects produced by dilution of the oral dose. Toxicol. Appl. Pharmacol. 19 164-168. Brandau, R. and Lippold, B.H. (1982). Dermal and Transdermal Absorption. Wissenschaf-tliche, Verlagsgesellschaft mbH, Stuttgart. 

Buchan [92] has carried out a study using electron microscopy combined with energy dispersive X-ray analysis, to determine the location and nature of the stored phosphorus in activated sludge samples from seven different treatment plants in South Africa, which all show enhanced phosphorus removal. The results indicate that there is a biological mechanism of enhanced phosphorus uptake in activated sludge. 

Among several fluorescence properties, fluorescence quantum yield and lifetime are the two most important characteristics of a fluorophore. Studies of the effects of the silica nanomatrixes on these two characteristics reveal the mechanism of enhanced fluorescence intensity of DDSNs. 

Of these the last one has been most widely used, since heparin-modified polymeric materials exhibit the highest and by today unsurpassed effects of thromboresistance enhancement. Many of these materials have not only proved to be potent in trials on animals, but have already found clinical application. These achievements have stimulated continuous interest in heparin-containing polymers (HCP) which is best manifested by listing the investigations performed in the field in recent years and still under way. They involve the new procedures for the synthesis of HCP providing minimal loss of activity of bound heparin, the studies of interactions of HCP with blood and its individual components, as well as on the mechanism of enhanced thromboresistance of HCP, and the search for new tasks for HCP. 

The year of 1961, when Vincent Gott11 observed the inhibition of thrombus formation by immobilized heparin for the first time, was marked as the second birth date of heparin, since it was for the first time isolated from liver tissue. Its anticoagulant action was detected in 1892. Although more than 20 years have passed since Gott s publication, there is still much confusion concerning the views on the mechanism of enhanced thromboresistance of heparin-modified polymers, which greatly hinders the introduction of HCP into clinical practice. 

Mechanism of Enhanced Thromboresistance of Polymeric Materials in the Presence of Heparin... 

The results discussed in the previous Section permits to make some assumptions regarding the mechanism of enhanced thromboresistance of HCP. Two self-excluding viewpoints concerning the problem coexist in the literature. The first one implies the elution of heparin from a polymeric surface into the bloodstream which prevents clotting in a way common for the anticoagulant itself64,67 73). According to the second, the... 

To clarify the mechanism of enhanced thromboresistance of such polymers, the state of the blood clotting system before and after the contact with the polymer was examined I36) (Table 19). Obviously, the changes of the blood clotting system parameters are of the same type as those accompanying the interaction of blood with HCP (see Table 16) but essentially exceeding the latter. Consequently, the heparin-protease-... 

Nakanishi, K., et al. 1984. Mechanism of enhancement of rectal permeability of drugs by nonsteroidal anti-inflammatory drugs. Chem Pharm Bull 32 3187. 

A permeation enhancer can be defined as a compound that alters the skin barrier function so that a desired drug can permeate at a faster rate. Dozens of enhancers are patented each year, and several books have been written summarizing the work and proposing mechanisms of enhancement.70-72 The permeation enhancers may be classified simply as polar and nonpolar ones. They can be used individually or in combination, such as binary mixtures. For several drugs, the flux across skin was observed to be linear with that of the most widely used enhancer, ethanol.73-75 Another polar enhancer, isopropanol, facilitated ion association of charged molecules and enhanced the transport of both neutral and ionic species across the stratum corneum.76 77 While polar enhancers traverse the skin, nonpolar enhancers are largely retained in the stratum corneum both aspects make the combination a superior enhancer to the individual enhancers.78... 

Froment DPH, Molitoris BA, Buddington B, et al. 1989b. Site and mechanism of enhanced gastrointestinal absorption of aluminum by citrate. Kidney Int 36 978-984. 

M. Yamada, Y. Uda, and Y. Tanigawara, Mechanism of enhancement of percutaneous absorption of molsidomine by oleic acid, Chem. Pharm. Bull. 35 3399-3406 (1987). 

D Sammett, AR Tall. Mechanisms of enhancement of cholesteryl ester transfer protein activity by lipolysis. J Biol Chem 260 6687-6697, 1985. 

Schmiedlin-Ren P, Edwards DJ, Fitzsimmons ME, et al. Mechanisms of enhanced oral availability of CYP3A4 substrates by grapefruit constituents decreased... 

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