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Only a fraction of the total number of per‐ and polyfluoroalkyl substances (PFAS) are monitored on a routine basis using targeted chemical analyses. We report on an approach toward identifying bioactive substances in environmental samples using effect‐directed analysis by combining toxicity testing, targeted chemical analyses, and suspect screening. PFAS compete with the thyroid hormone thyroxin (T4) for binding to its distributor protein transthyretin (TTR). Therefore, a TTR‐binding bioassay was used to prioritize unknown features for chemical identification in a PFAS‐contaminated sediment sample collected downstream of a factory producing PFAS‐coated paper. First, the TTR‐binding potencies of 31 analytical PFAS standards were determined. Potencies varied between PFAS depending on carbon chain length, functional group, and, for precursors to perfluoroalkyl sulfonic acids (PFSA), the size or number of atoms in the group(s) attached to the nitrogen. The most potent PFAS were the seven‐ and eight‐carbon PFSA, perfluoroheptane sulfonic acid (PFHpS) and perfluorooctane sulfonic acid (PFOS), and the eight‐carbon perfluoroalkyl carboxylic acid (PFCA), perfluorooctanoic acid (PFOA), which showed approximately four‐ and five‐times weaker potencies, respectively, compared with the native ligand T4. For some of the other PFAS tested, TTR‐binding potencies were weak or not observed at all. For the environmental sediment sample, not all of the bioactivity observed in the TTR‐binding assay could be assigned to the PFAS quantified using targeted chemical analyses. Therefore, suspect screening was applied to the retention times corresponding to observed TTR binding, and five candidates were identified. Targeted analyses showed that the sediment was dominated by the di‐substituted phosphate ester of N‐ethyl perfluorooctane sulfonamido ethanol (SAmPAP diester), whereas it was not bioactive in the assay. SAmPAP diester has the potential for (bio)transformation into smaller PFAS, including PFOS. Therefore, when it comes to TTR binding, the hazard associated with this substance is likely through (bio)transformation into more potent transformation products. Environ Toxicol Chem 2024;43:245–258. © 2023 The Authors. Environmental Toxicology and Chemistry published by Wiley Periodicals LLC on behalf of SETAC. [ABSTRACT FROM AUTHOR]

The structural performance of four reinforced concrete pile cap specimens anchored by widely used proprietary high-strength threaded bars (HSTBs) and subjected to column uplift loads is investigated. The specimens were full-scale replicas of in-service foundations in terms of geometry, material properties, reinforcement details, and loading conditions. The study also included isolated pullout tests of HSTB anchorages. Two of the specimens were modified by increasing the embedment depth of the column anchor plate to assess effectiveness as a possible retrofit approach. Failure of all specimens was brittle without yielding of embedded reinforcing steel. Moreover, the ultimate pullout capacity of the anchors was not achieved in any of the specimens. ACI 318-19 provisions underestimated the concrete breakout capacity of all specimens and were unable to incorporate the beneficial effects of the column anchor plate modification as it only considered the anchor embedment length and edge distance as critical parameters for calculating strength. [ABSTRACT FROM AUTHOR]