Induction consequences

Consequences of inhibiting drug metabolism can be more profound than those of enzyme induction. Effects of enz5rme inhibition by drugs also tend to be more selective than those of enz5une induction. Consequently, enz3une inhibition offers more scope for therapy (see Table 7.4). 

The basis for these changes is unclear but is thought to reflect enzyme induction consequent to cellular thymidylate lack... 

Induction laws and experiments show that the impedance of a coil crossed by an AC current put near a conductive piece is modified by the creation of eddy currents. The presence of an anomaly in this material structure modifies the impedance of the generating coil. The impedance variation measure is at the root of non destructive testing by eddy currents. Any variation inside a piece (variation of conductivity or permeability) modifies the intensity and the course of the eddy currents and consequently the coil impedance. 

Eddy currents and the magnetic flux that is associated to them are proportional to the radial distance of the coil center. The magnetic flux is proportional to the probe induction and consequently to the passing current. The theoretic calculation of this induction is given by the following equation ... 

Samples to be examined by inductively coupled plasma and mass spectrometry (ICP/MS) are commonly in the form of a solution that is transported into the plasma flame. The thermal mass of the flame is small, and ingress of excessive quantities of extraneous matter, such as solvent, would cool the flame and might even extinguish it. Even cooling the flame reduces its ionization efficiency, with concomitant effects on the accuracy and detection limits of the ICP/MS method. Consequently, it is necessary to remove as much solvent as possible which can be done by evaporation off-line or done on-line by spraying the solution as an aerosol into the plasma flame. 

The magnetic field rotates at a synchronous speed, so it should also rotate the rotor. But this is not so in an induction motor. During start-up, the rate of cutting of llux is the maximum and so is the induced e.m.f. in the rotor circuit. It diminishes with motor speed due to the reduced relative speed between the rotor and the stator flux. At a synchronous speed, there is no linkage of flux and thus no induced e.m.f. in the rotor circuit, consequently the torque developed is zero. 

Kinetic studies involving enzymes can principally be classified into steady and transient state kinetics. In tlie former, tlie enzyme concentration is much lower tlian that of tlie substrate in tlie latter much higher enzyme concentration is used to allow detection of reaction intennediates. In steady state kinetics, the high efficiency of enzymes as a catalyst implies that very low concentrations are adequate to enable reactions to proceed at measurable rates (i.e., reaction times of a few seconds or more). Typical enzyme concentrations are in the range of 10 M to 10 ], while substrate concentrations usually exceed lO M. Consequently, tlie concentrations of enzyme-substrate intermediates are low witli respect to tlie total substrate (reactant) concentrations, even when tlie enzyme is fully saturated. The reaction is considered to be in a steady state after a very short induction period, which greatly simplifies the rate laws. 

In transforming bis-ketone 45 to keto-epoxide 46, the elevated stereoselectivity was believed to be a consequence of tbe molecular shape — tbe sulfur ylide attacked preferentially from tbe convex face of the strongly puckered molecule of 45. Moreover, the pronounced chemoselectivity was attributed to tbe increased electropbilicity of the furanone versus the pyranone carbonyl, as a result of an inductive effect generated by tbe pair of spiroacetal oxygen substituents at tbe furanone a-position. ... 

The assumed transition state for this reaction is shown in Scheme 5.5. The two bulky t-butoxy groups are expected to locate at the two apical positions. One of the 3,3 -phenyl groups would effectively shield one face of an imine, and consequently, a diene attacks from the opposite side. Judging from this model, similar selectivities were expected in the Mannich-type reactions of imines with silyl eno-lates. Actually, when ligand 10 was used in the reaction of imine la with S-ethyl-thio-l-trimethylsiloxyethene, the corresponding / -amino thioester was obtained in 84% ee (Scheme 5.6). As expected, the sense of the chiral induction in this case was the reverse of that observed when using catalyst 6 [12, 25]. 

The carbonyl carbon of an unsymmetrical ketone is a prochiral center reaction with a Grignard reagent 2 (R 7 R, R") can take place on either face of the carbonyl group with equal chance. The products 8a and 8b are consequently formed in equal amounts as racemic mixture, as long as no asymmetric induction becomes effective ... 

Folgerung, /. conclusion, inference, induction. Folge wirkung,/. resultant, consequence, -zeit, /. period following, folglich, adv. consequently, folgsam, a. obedient. 

Since the deep and shallow curve of the MWD log and the deep, shallow and guard (laterolog) of the wireline log shows a departure, the zone 2274-2356 ft is invaded, consequently permeable. Using the dual induction chart of Figure 4-304, we can plot the point at 2290 ft ... 

Electricity is normally charged for on the basis of power (kilowatts) and the supply authority must install plant whose rating (and therefore cost) is a function of the voltage of the system and the current which the consumer takes (i.e. kilo-volt-amps). The relationship between the two is kW = kVA x cos (j> where cos (j> is the power factor and is less than 1.0. In the case of loads which have a low power, factor the supply authority is involved in costs for the provision of plant which are not necessarily reflected in the kWh used. A penalty tariff may then be imposed which makes it economically worthwhile for the consumer to take steps to improve his power factor. Low power factors occur when the load is predominantly either inductive or capacitive in nature (as opposed to resistive). In most industrial circumstances where the load includes a preponderance of motors, the load is inductive (and the power factor is therefore lagging). Consequently, if the power factor is to be brought nearer to unity the most obvious method is to add a significant capacitive component to the load. 

As a consequence of the pericyclic reaction path, the addition of a-stereogenic allylmctals to carbonyl compounds is accompanied by an effective 1,3-chirality transfer in the allylic moiety combined with 1,4-chira induction at the prostereogenic carbonyl group3032. The scheme also demonstrates the importance of the orientation of the substituent X in the six-membered transition state. By changing from a pseudo-axial to a pseudo-equatorial position, the cation-induced sy/i-attack addresses opposite faces of both prostereogenic moieties, leading to a Z-and an -isomer, these being enantiomeric in respect to the chiral moiety. 

It is interesting to speculate that asymmetric induction may be the consequence of the exo anomeric effect, a stereoelectronic effect that favors the conformation 5 that places the aglycone O-C bond antiperiplanar to the pyran C(1) —C(2) bond7fi. Related asymmetric induction has also been observed in aldehyde addition reactions of the related, but racemic, pinacol (Z)-y-(tetrahydropyranyloxy)allylboronate49. As indicated in the examples above, however, the level of diastereoselectivity is modest and the only application in asymmetric synthesis is Wuts exo-brevicomin synthesis75. 

This explains the increase in the induction period which is apparent after exposure of the salt to ammonia, and the decrease in the induction period found for samples which contain traces of HCIO4, identified as the unstable species [59,925]. In the low temperature range, the presence of an outer layer of adsorbed NH3 and/or NH4 ions suppresses the formation of HC104 and, in consequence, the decomposition reaction. 

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