Agent investigating

In a cross-sectional study, exposure and effect are studied simultaneously. This approach contains an inherent problem because exposure must precede the effect. However, it can he used to investigate acute effects and also mild chronic effects (which do not force people to leave their jobs) if exposure has remained rather stable for a long time. When the prevalence of the effects studied are compared with the prevalence in other worker groups (controls or references) which correspond otherwise with the study group but are not exposed to the agent investigated, indicative evidence of possible causality may be obtained. For example, cross-sectional studies have been applied successfully to reveal the associations between mild neurotoxic effects and exposure to organic solvents. ... 

Aromatic biguanides such as proguanil (181) have been found useful as antimalarial agents. Investigation of the metabolism of this class of drugs revealed that the active compound was in fact the triazine produced by oxidative cyclization onto the terminal alkyl group. The very rapid excretion of the active entity means that it cannot be used as such in therapy. Consequently, treatment usually consists in administration of either the metabolic precursor or, alternately, the triazine as some very insoluble salt to provide slow but continual release of drug. 

What follows is a personal perspective on the clinical study of incapacitating agents investigated in the 1960s. Although in retirement, I felt it important to document the fascinating and informative details of a decade of scientific work might otherwise be lost forever. 

ATP c1-c4) Potential exo-active-site-dlrected agents investigated Hampton et eJ.( 47-50). 

Of the two surface-active agents investigated, the Duponol C, manufd by the duPont Co, is a solid and said to contain Na lauryl sulfate, while the Span 85, manufd by the Atlas Powder Co, is an oily liq and said.to contain sorbitol trioleate. The use of Span 85 is preferred because, being purely organic, it does not contain any metallic ions, such as Na and also because, being a liquid, it dissolves quicker in molten TNT... 

Characteristic for the commercial complexing agents investigated in this work is the fact that the maximum current-lowering effect is already attained in the presence of additive concentrations that are much lower than those used in practice, and this is illustrated in Fig. 5.2. The manufacturers of the additive mixtures all refused to communicate the identity and concentration of the complexing agent in the mixtures. In the case of what is here called in short adsorption of an additive , it most likely concerns complex adsorption equilibria, where synergist effects between the different components can play a part. 

In the first case, eq. (6.5), the necessary centrifugal acceleration n2d only depends on the foam parameters S and cT, these being independent of gas throughput q A qf. These foams can be easily controlled. (With the exception of Mersolat H (a = 0.40), the foaming agents investigated in [17] did not comply with this behaviour, here a = 0.45)... 

Block polymers were prepared by organolithium-initiated polymerization in cyclohexane solution by using the sequential monomer addition technique (3). Polymers were both of the linear-SBS and radial -branched (SB) type. Blends were prepared in cyclohexane solution, either before or after coupling the initially linear SBLi precursor. Coupling agents investigated were ethyl acetate (for linear coupling), epoxi-aized soybean oil (ESO), and SiCh. 

Tweedle, M.F. (1992) Physicochemical properties of gadoteridol and other magnetic resonance contrast agents. Investigative Radiology, 27, S2-S6. 

There is a lack of consensus on the best re-treatment protocol for patients who develop hepatotoxicity during treatment with standard antituberculosis agents. Investigators from Turkey have reported a high risk of recurrence of hepatitis (in six of 25 patients) on re-introduction of all drugs in full doses after recovery from hepatitis (31). This risk was less when rifampicin and isonia-zid were re-introduced sequentially in increasing doses and when pyrazinamide was replaced by streptomycin. 

Summary The fluorescence behavior of covalent bonded probes was investigated in linear and crosslinked polydimethylsiloxanes. The probe shows a dual emission that depends on the network density and the concentration on swelling agent. Investigations of linear polydimethylsiloxanes with a bonded probe as a function of TUF concentration indicate the existence of ground state complexes between the solvent and the probe molecule. 

In the absence of empirically intensive studies of cross adaptation (Kohbara and Ca-prio 1996) there currently are no models that accurately predict the nature of the interaction of mixtures, regardless of the sensory system studied or bioassay used. In the absence of any theoretical models that describe the interactions of agents, investigators have used descriptive models based on data. Isobole approaches use averaging models to define the null condition of no interaction, then go on to provide a descriptive index of enhancement or suppression using concentrations, responses, and empirical concentration-response relationships (Suhnel, 1993). This approach is useful because it can be applied to systems for which mechanistic information driving the concentration-response is not available (see methods). 

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