INDEX biological effects

It may be of value to differentiate the indicating and monitoring uses of plants. Most reported work has used the indicator concept, with plant injury (symptoms) as indicative of a problem. Monitoring implies some degree of reliability. Several studies have attempted to use plant response as a monitor of pollution concentrations or doses, with variable but uncertain success. Plants could also be considered monitors if th gave a reliable index of the biologic effects on biologic systems of concern to man (crops, forests, animals, and man himself). The latter has not been seriously discussed. 

Welt, I. D., Bull. Med. Library Assoc. 46, 367-80 (1958). Detailed indexing of biological effects of chemical substances. 

From the point of view of synthetic effort, preparation of combinatorial mixtures is by far the most economical approach. It can be done with ordinary laboratory equipment and does not take more time than the synthesis of any one of the individual components of the library. This simplicity, however, has its price firstly, the more components a mixture contains the more difficult it becomes to follow the reaction analytically and to determine the actual composition of the reaction product. Secondly, if hits are found in a biological assay, deconvolution is required. In most cases this is done via resynthesis either of the individual components or of subsets of the mixture. If the composition of the initial mixtures was carefully planned it may be possible to identify the active component(s) by simply comparing the composition of the active mixtures with those of the inactive ones. Corresponding procedures have been reported in the literature (e.g., the techniques of indexed [1,2] and orthogonal [3] chemical libraries have been used in solution-phase synthesis). However, the biological effect of a mixture may also be due to a combined action of several weakly active members, with the result that deconvolution does not identify a significantly active compound. Finally, the problem of impurities multiplies with the complexity of the mixtures. 

Endpoint—biological effect used as an index of the effect of a chemical on an organism... 

A. S. Mayhoub et.al. [104] s)mthesized a sequence of third-generation referents of methyl 4-(dibromomethyl)-2-(4-chlorophenyl)thiazole-5-carboxylate 120, which had the highly potent antiviral activity comparable to the first and second generation derivatives, have been s)mthesized and verified against yellow fever virus consuming a cell-based assay. The compounds were aimed at the objectives of enlightening metabolic stability, therapeutic index, and antiviral potency. The biological effects of C4 and C5 substitution were studied. The... 

In the previous sections an attempt has been made to define the major pathways of human exposure to lead and then to examine the resultant blood lead concentration as a biological indicator of this exposure. It thus follows that the biological effects should, in so far as possible, be likewise related to this same index of exposure, the blood lead concentration. Furthermore, it is this mobile lead in the bloodstream that is the cause of the adverse effects of lead. 

For the application of QDs to three-dimensional biological imaging, a large two-photon absorption cross section is required to avoid cell damage by light irradiation. For application to optoelectronics, QDs should have a large nonlinear refractive index as well as fast response. Two-photon absorption and the optical Kerr effect of QDs are third-order nonlinear optical effects, which can be evaluated from the third-order nonlinear susceptibility, or the nonlinear refractive index, y, and the nonlinear absorption coefficient, p. Experimentally, third-order nonlinear optical parameters have been examined by four-wave mixing and Z-scan experiments. 

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