Reduction of sensitizers

Nowadays, rhodium or ruthenium are often the preferred catalysts. Rhodium can be used under mild conditions, whereas ruthenium needs elevated pressures. If pressure is available, it might as well be used even with rhodium, for increased pressure makes more efficient use of the catalyst, as well as decreases whatever hydrogenolysis might occur at lower pressure. Rhodium 7,8,12 20,21,38,39,45,65,66,68,69,75) and ruthenium 18,26 8,52,68,69,72,74) are especially advantageous in reductions of sensitive phenols and phenyl ethers that undergo extensive hydrogenolysis over catalysts such as platinum oxide. 

Turriziani O, AntoneUi G, Jacobsen H, Mous J, Riva E, Pistello M, Dianzani F (1994) Identification of an amino acid substitution involved in the reduction of sensitivity of HIV-1 to an inhibitor of... 

Changes in human immunodeficiency vims type 1 Gag at positions 1449 and P453 are linked to I50V protease mutants in vivo and cause reduction of sensitivity to amprenavir and improved viral fitness in vitro. J Virol 76 7398-7406... 

Disadvantages of this method lie in the reduction of sensitivity and the extra noise which is produced by the linearizing network. 

Although AAS is predominantly used as a technique for trace analysis, a significant demand for a reduction of sensitivity has been created by the technique of... 

Since the introduction of nitroglycerine as an explosive by Alfred Nobel in 1867 in the form of Dynamite, large advances have been made in the performance and reduction of sensitivities of highly energetic materials (Fig. 12.1). However, most of the formulations currently used are over 50 years old and do not fulfill all of today s requirements, in particular with regard to their performance, collateral damage, insensitivity, toxicity, compatibility with the environment and use in special operations. 

Hypertension, by reducing intravascular volume and probably by other mechanisms too, e.g. reduction of sensitivity to noradrenergic vasoconstriction. 

The comparison of open and closed-loop responses (12.37) and (12.38) reveals that the sensitivity function S gives the reduction of sensitivity to disturbances, achieved by feedback control. It is evident that S =0 and T = 1 are desirable. In this way, the output follows perfectly the setpoint, and the process is not affected by disturbances. Both can be achieved by large controller gain, that is oo. However, large controller gain leads to instability, which sets limits on the achievable closed-loop performance. 

MW energy has been shown to accelerate the reduction of many key functional groups in organic chemistry, and Banks and Wagner have recently reviewed the area. In many examples, mild reagents and reaction conditions have been developed, and it has been demonstrated that the technique is widely applicable for the reduction of sensitive substrates the use of supported reagents has reduced the need for solvents and permitted shorter reaction times. The higher yields of products have also simplified the work-up procedures. 

Thermobalances are available in two different designs, i. e. a horizontal construction (Fig. 5-1) and vertical construction. For the vertical construction there are two different versions the top-loading balance, which has the oven above the balance (Fig. 5-2), and the thermobalance with the sample tray hanging on a thin hangdown wire into the oven below the balance (Fig. 2-4). The suppliers claim some advantages for the horizontal arrangement such as complete lack of buoyancy, the avoidance of condensation in the balance cabinet, and the reduction of sensitivity to vibration. However the last two points cannot be confirmed by the author s experience. Despite an efficacious gas flow, a diffusion of condensates was observed opposite to the flow direction of the gas. The sensitivity to vibrations seems to be comparable with the vertical design. Of the vertically constructed balances, the top loader is more convenient to manipulate. 

Interference due to protein, especially haemoglobin, results in a reduction of sensitivity, and proteins should therefore be removed prior to analysis of sialic acid. A method using ethanol/chloroform precipitation has been put forward (Rivetz et al. 1980), but such deproteination methods still require additional correction for lipid, and the ion-exchange purification and lipid extraction should be part of the procedure to achieve reproducible and accurate quantitation (LEDEENandYu 1976, Schauer 1978, 1982). 

N. Tomiya, K. Watanabe, J. Awaya, M. Kurono, S. Eujii, Modification of acyl-plasmin-streptokinase complex with polyethylene glycol reduction of sensitivity to neutralizing antibody. FEES Lett., 193 (1) 44-48. 

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