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Binding of chemicals lo the estrogen receptor (ER) is known to be a key mode of action of endocrine disruption effects. In this study, combined quantitative structure-activity relationship (QSAR) models from discriminant and multilinear regression (MLR) analyses, termed a two-step model, were developed. These were used to predict the binding potency to human ERα of four chemical groups, namely alkylphenols. phthalales, diphenylethanes and benzophenones. These groups are considered to be important chemical classes of ER-binders. The descriptors Investigated were calculated following the simulation of docking between the receptor and ligand. Discriminant analysis in the first step of a two-step model was applied to distinguish binders from non-binders. It had a concordance, following leave-one-out (LOO), of greater than 87% for all chemical classes. Binders were defined as chemicals whose IC50 was reliably measured in a competitive binding assay. The MLR analysis in the second step was performed for the quantitative prediction of the binding affinity of chemicals that were previously discriminated as binders. The q² values for alkylphenols and diphenylethanes were 0.75 and 0.74, respectively. However good MLR relationships were not obtained for phthalates and benzophenone as the observed binding affinities of chemicals in these categories were weak and in a too narrow range. [ABSTRACT FROM AUTHOR]

We developed a hybrid integrated optical module for 1.3/1.55-μm wavelength-division multiplexing (WDM) full-duplex operation. The optical circuit was designed to suppress the optical and electrical crosstalk using a wavelength division multiplexing filter, and an optical crosstalk of -43 dB and an electrical crosstalk of -105 dB were achieved with a separation between the transmitter laser diode and the receiver photodiode of more than 9 mm. We used the optical circuit design to fabricate an optical module with a bare chip preamplifier in a package. This module exhibited a full duplex operation of 156 Mbit/s with a minimum sensitivity of -35.2 dBm at a bit error rate of 10-10 [ABSTRACT FROM PUBLISHER]