Emissive Guanosine Analog Applicable for Real-Time Live Cell Imaging.

A new emissive guanosine analog CF3thG, constructed by a single trifluoromethylation step from the previously reported thG, displays red-shifted absorption and emission spectra compared to its precursor. The impact of solvent type and polarity on the photophysical properties of CF3thG suggests that the electronic effects of the trifluoromethyl group dominate its behavior and demonstrates its susceptibility to microenvironmental polarity changes. In vitro transcription initiations using T7 RNA polymerase, initiated with CF3thG, result in highly emissive 5'-labeled RNA transcripts, demonstrating the tolerance of the enzyme toward the analog. Viability assays with HEK293T cells displayed no detrimental effects at tested concentrations, indicating the safety of the analog for cellular applications. Live cell imaging of the free emissive guanosine analog using confocal microscopy was facilitated by its red-shifted absorption and emission and adequate brightness. Real-time live cell imaging demonstrated the release of the guanosine analog from HEK293T cells at concentration-gradient conditions, which was suppressed by the addition of guanosine.

Persistence and pathway of glyphosate degradation in the coastal wetland soil of central Delaware.

Glyphosate is a globally dominant herbicide. Here, we studied the degradation and microbial response to glyphosate application in a wetland soil in central Delaware for controlling invasive species (Phragmites australis). We applied a two-step solid-phase extraction method using molecularly imprinted polymers designed for the separation and enrichment of glyphosate and aminomethylphosphonic acid (AMPA) from soils before their analysis by ultra-high-performance liquid chromatography (UHPLC) and Q Exactive Orbitrap mass spectrometry methods. Our results showed that approximately 90 % of glyphosate degraded over 100 d after application, with AMPA being a minor (<10 %) product. Analysis of glyphosate-specific microbial genes to identify microbial response and function revealed that the expression of the phnJ gene, which codes C-P lyase enzyme, was consistently dominant over the gox gene, which codes glyphosate oxidoreductase enzyme, after glyphosate application. Both gene and concentration data independently suggested that C-P bond cleavage-which forms sarcosine or glycine-was the dominant degradation pathway. This is significant because AMPA, a more toxic product, is reported to be the preferred pathway of glyphosate degradation in other soil and natural environments. The degradation through a safer pathway is encouraging for minimizing the detrimental impacts of glyphosate on the environment.

Self-Reporting Therapeutic Protein Nanoparticles.

We present a modular strategy to synthesize nanoparticle sensors equipped with dithiomaleimide-based, fluorescent molecular reporters capable of discerning minute changes in interparticle chemical environments based on fluorescence lifetime analysis. Three types of nanoparticles were synthesized with the aid of tailor-made molecular reporters, and it was found that protein nanoparticles exhibited greater sensitivity to changes in the core environment than polymer nanogels and block copolymer micelles. Encapsulation of the hydrophobic small-molecule drug paclitaxel (PTX) in self-reporting protein nanoparticles induced characteristic changes in fluorescence lifetime profiles, detected via time-resolved fluorescence spectroscopy. Depending on the mode of drug encapsulation, self-reporting protein nanoparticles revealed pronounced differences in their fluorescence lifetime signatures, which correlated with burst- vs diffusion-controlled release profiles observed in previous reports. Self-reporting nanoparticles, such as the ones developed here, will be critical for unraveling nanoparticle stability and nanoparticle-drug interactions, informing the future development of rationally engineered nanoparticle-based drug carriers.

A multivariate statistical approach to wrinkling detection in composites.

Non-destructive inspection using ultrasound in materials such as carbon-fibre reinforced polymers (CFRP) is challenging as the ultrasonic wave will scatter from each ply in the structure of the component. This may be improved by using image processing algorithms such as the total focusing method (TFM), however the high level of backscattering within the sample is very likely to obscure a signal arising from a flaw. Detection of wrinkling, or out-of-plane fibre waviness, is especially difficult to automate as no additional scattering is produced (as might be the case with delaminations). Instead, wrinkling changes how a signal is scattered due to the physical displacement of ply layers from their expected location. In this paper, we propose a method of detecting wrinkling by examining the regional variations in image intensity, which are expected to be highly correlated between similar ply layers in the structure. By characterising the 2-dimensional spatial autocorrelation of an area surrounding a given location in the image of pristine components, the distribution of acceptable values is estimated. Wrinkling is observed to correspond with a significant deviation from this distribution, which is readily detected. A comparison is made with an alternative image processing approach identified from the literature, finding that the proposed method has equivalent performance for large wrinkling amplitudes, and better performance for low wrinkling amplitudes.

Multimodal optical imaging of the oculofacial region using a solid tissue-simulating facial phantom.

Significance: Spatial frequency domain imaging (SFDI) applies patterned near-infrared illumination to quantify the optical properties of subsurface tissue. The periocular region is unique due to its complex ocular adnexal anatomy. Although SFDI has been successfully applied to relatively flat in vivo tissues, regions that have significant height variations and curvature may result in optical property inaccuracies. Aim: We characterize the geometric impact of the periocular region on SFDI imaging reliability. Approach: SFDI was employed to measure the reduced scattering coefficient ( µ s ' ) and absorption coefficient ( µ a ) of the periocular region in a cast facial tissue-simulating phantom by capturing images along regions of interest (ROIs): inferior temporal quadrant (ITQ), inferior nasal quadrant (INQ), superior temporal quadrant (STQ), central eyelid margin (CEM), rostral lateral nasal bridge (RLNB), and forehead (FH). The phantom was placed on a chin rest and imaged nine times from an "en face" or "side profile" position, and the flat back of the phantom was measured 15 times. Results: The measured µ a and µ s ' of a cast facial phantom are accurate when comparing the ITQ, INQ, STQ, and FH to its flat posterior surface. Paired t tests of ITQ, INQ, STQ, and FH µ a and µ s ' concluded that there is not enough evidence to suggest that imaging orientation impacted the measurement accuracy. Regions of extreme topographical variation, i.e., CEM and RLNB, did exhibit differences in measured optical properties. Conclusions: We are the first to evaluate the geometric implications of wide-field imaging along the periocular region using a solid tissue-simulating facial phantom. Results suggest that the ITQ, INQ, STQ, and FH of a generalized face have minimal impact on the SFDI measurement accuracy. Areas with heightened topographic variation exhibit measurement variability. Device and facial positioning do not appear to bias measurements. These findings confirm the need to carefully select ROIs when measuring optical properties along the periocular region.

Manipulating the EphB4-ephrinB2 axis to reduce metastasis in HNSCC.

The EphB4-ephrinB2 signaling axis has been heavily implicated in metastasis across numerous cancer types. Our emerging understanding of the dichotomous roles that EphB4 and ephrinB2 play in head and neck squamous cell carcinoma (HNSCC) poses a significant challenge to rational drug design. We find that EphB4 knockdown in cancer cells enhances metastasis in preclinical HNSCC models by augmenting immunosuppressive cells like T regulatory cells (Tregs) within the tumor microenvironment. EphB4 inhibition in cancer cells also amplifies their ability to metastasize through increased expression of genes associated with epithelial mesenchymal transition and hallmark pathways of metastasis. In contrast, vascular ephrinB2 knockout coupled with radiation therapy (RT) enhances anti-tumor immunity, reduces Treg accumulation into the tumor, and decreases metastasis. Notably, targeting the EphB4-ephrinB2 signaling axis with the engineered EphB4 ligands EFNB2-Fc-His and Fc-TNYL-RAW-GS reduces local tumor growth and distant metastasis in a preclinical model of HNSCC. Our data suggest that targeted inhibition of vascular ephrinB2 while avoiding inhibition of EphB4 in cancer cells could be a promising strategy to mitigate HNSCC metastasis.

Impact of Chemotherapy Educational Videos for Patients with Acute Myeloid Leukemia.

Patient education in acute myeloid leukemia (AML) has become increasingly complex with the introduction of new treatments and chemotherapy regimens. Video education presents an opportunity to supplement traditional patient education and address some of the gaps associated with standard methods. This single-center study sought to assess the potential impact of supplemental video education on patients receiving induction chemotherapy for AML. Participants were consented to be randomized to receive their education with or without a supplemental video designed for their treatment regimen. We then provided a survey to each participant to assess knowledge retention, anxiety, and overall satisfaction with their care. Patients that received video education were found to have significantly improved knowledge retention compared to those that did not. There were no differences detected in anxiety or patient satisfaction. Video education appears to be an effective supplemental method for patient education in AML. Limitations include the single-center nature of the study at an urban academic medical center with a relatively well-educated, primarily Caucasian, younger population. Future research is warranted to assess the video in a diverse set of languages and to explore its broader benefits.

The Structure of the LysR-type Transcriptional Regulator, CysB, Bound to the Inducer, N-acetylserine.

In Escherichia coli and Salmonella typhimurium, cysteine biosynthesis requires the products of 20 or more cys genes co-ordinately regulated by CysB. Under conditions of sulphur limitation and in the presence of the inducer, N-acetylserine, CysB binds to cys promoters and activates the transcription of the downstream coding sequences. CysB is a homotetramer, comprising an N-terminal DNA binding domain (DBD) and a C-terminal effector binding domain (EBD). The crystal structure of a dimeric EBD fragment of CysB from Klebsiella aerogenes revealed a protein fold similar to that seen in Lac repressor but with a different symmetry in the dimer so that the mode of DNA binding was not apparent. To elucidate the subunit arrangement in the tetramer, we determined the crystal structure of intact CysB in complex with N-acetylserine. The tetramer has two subunit types that differ in the juxtaposition of their winged helix-turn-helix DNA binding domains with respect to the effector binding domain. In the assembly, the four EBDs form a core with the DNA binding domains arranged in pairs on the surface. N-acetylserine makes extensive polar interactions in an enclosed binding site, and its binding is accompanied by substantial conformational rearrangements of surrounding residues that are propagated to the protein surface where they appear to alter the arrangement of the DNA binding domains. The results are (i) discussed in relation to the extensive mutational data available for CysB and (ii) used to propose a structural mechanism of N-acetylserine induced CysB activation.

Differences in stomatal sensitivity to CO2 and light influence variation in water use efficiency and leaf carbon isotope composition in two genotypes of the C4 plant Zea mays.

The ratio of net CO2 uptake (Anet) and stomatal conductance (gs) is an intrinsic measurement of leaf water use efficiency (WUEi) however its measurement can be challenging for large phenotypic screens. Measurements of leaf carbon isotope composition (δ13Cleaf) may be a scalable tool to approximate WUEi for screening because it in part reflects the competing influences of Anet and gs on the CO2 partial pressure (pCO2) inside the leaf over time. However, in C4 photosynthesis the CO2 concentrating mechanism complicates the relationship between δ13Cleaf and WUEi. Despite this complicated relationship, several studies have shown genetic variation in δ13Cleaf across C4 plants. Yet there has not been a clear demonstration of whether Anet or gs are the causal mechanisms controlling WUEi and δ13Cleaf. Our approach was to characterize leaf photosynthetic traits of two Zea mays recombinant inbred lines (Z007E0067 and Z007E0150) which consistently differ for δ13Cleaf even though they have minimal confounding genetic differences. We demonstrate that these two genotypes contrasted in WUEi driven by differences in the speed of stomatal responses to changes in pCO2 and light that lead to unproductive leaf water loss. These findings provide support that differences in δ13Cleaf in closely related genotypes do reflect greater WUEi and further suggests that differences in stomatal kinetic response to changing environmental conditions is a key target to improve WUEi.

Minding the margins: Evaluating the impact of COVID-19 among Latinx and Black communities with optimal qualitative serological assessment tools.

COVID-19 disproportionately affected minorities, while research barriers to engage underserved communities persist. Serological studies reveal infection and vaccination histories within these communities, however lack of consensus on downstream evaluation methods impede meta-analyses and dampen the broader public health impact. To reveal the impact of COVID-19 and vaccine uptake among diverse communities and to develop rigorous serological downstream evaluation methods, we engaged racial and ethnic minorities in Massachusetts in a cross-sectional study (April-July 2022), screened blood and saliva for SARS-CoV-2 and human endemic coronavirus (hCoV) antibodies by bead-based multiplex assay and point-of-care (POC) test and developed across-plate normalization and classification boundary methods for optimal qualitative serological assessments. Among 290 participants, 91.4% reported receiving at least one dose of a COVID-19 vaccine, while 41.7% reported past SARS-CoV-2 infections, which was confirmed by POC- and multiplex-based saliva and blood IgG seroprevalences. We found significant differences in antigen-specific IgA and IgG antibody outcomes and indication of cross-reactivity with hCoV OC43. Finally, 26.5% of participants reported lingering COVID-19 symptoms, mostly middle-aged Latinas. Hence, prolonged COVID-19 symptoms were common among our underserved population and require public health attention, despite high COVID-19 vaccine uptake. Saliva served as a less-invasive sample-type for IgG-based serosurveys and hCoV cross-reactivity needed to be evaluated for reliable SARS-CoV-2 serosurvey results. The use of the developed rigorous downstream qualitative serological assessment methods will help standardize serosurvey outcomes and meta-analyses for future serosurveys beyond SARS-CoV-2.

Advancing Tau PET Quantification in Alzheimer Disease with Machine Learning: Introducing THETA, a Novel Tau Summary Measure.

Alzheimer disease (AD) exhibits spatially heterogeneous 3- or 4-repeat tau deposition across participants. Our overall goal was to develop an automated method to quantify the heterogeneous burden of tau deposition into a single number that would be clinically useful. Methods: We used tau PET scans from 3 independent cohorts: the Mayo Clinic Study of Aging and Alzheimer's Disease Research Center (Mayo, n = 1,290), the Alzheimer's Disease Neuroimaging Initiative (ADNI, n = 831), and the Open Access Series of Imaging Studies (OASIS-3, n = 430). A machine learning binary classification model was trained on Mayo data and validated on ADNI and OASIS-3 with the goal of predicting visual tau positivity (as determined by 3 raters following Food and Drug Administration criteria for 18F-flortaucipir). The machine learning model used region-specific SUV ratios scaled to cerebellar crus uptake. We estimated feature contributions based on an artificial intelligence-explainable method (Shapley additive explanations) and formulated a global tau summary measure, Tau Heterogeneity Evaluation in Alzheimer's Disease (THETA) score, using SUV ratios and Shapley additive explanations for each participant. We compared the performance of THETA with that of commonly used meta-regions of interest (ROIs) using the Mini-Mental State Examination, the Clinical Dementia Rating-Sum of Boxes, clinical diagnosis, and histopathologic staging. Results: The model achieved a balanced accuracy of 95% on the Mayo test set and at least 87% on the validation sets. It classified tau-positive and -negative participants with an AUC of 1.00, 0.96, and 0.94 on the Mayo, ADNI, and OASIS-3 cohorts, respectively. Across all cohorts, THETA showed a better correlation with the Mini-Mental State Examination and the Clinical Dementia Rating-Sum of Boxes (ρ ≥ 0.45, P < 0.05) than did meta-ROIs (ρ < 0.44, P < 0.05) and discriminated between participants who were cognitively unimpaired and those who had mild cognitive impairment with an effect size of 10.09, compared with an effect size of 3.08 for meta-ROIs. Conclusion: Our proposed approach identifies positive tau PET scans and provides a quantitative summary measure, THETA, that effectively captures heterogeneous tau deposition observed in AD. The application of THETA for quantifying tau PET in AD exhibits great potential.

Cancer and pulmonary fibrosis risks in patients with dermatomyositis and polymyositis: A retrospective cohort study.

Background: This study assessed the risks of developing pulmonary fibrosis and cancer and whether patients are at risk of acquiring subsequent cancer after pulmonary fibrosis development. Methods: From the claims data of 22 million insured people, we identified 1461 patients with dermatomyositis (DM) and 1058 with polymyositis (PM) diagnosed in 1996-2016 and 50,380 comparison individuals without pulmonary fibrosis and cancer at baseline, matched by sex and age. Incident pulmonary fibrosis and cancer in each cohort were assessed at the end of 2016. We further followed up individuals with and without pulmonary fibrosis to assess the subsequent development of cancer. Results: The cancer incidence was 2.6-fold higher in the DM/PM groups combined than in comparisons (135.3 vs. 52.1 per 10,000 person-years), with an adjusted hazard ratio (aHR) of 3.11 (95 % confidence interval [CI] = 2.71-3.58). The incidence was lower in patients with PM than in those with DM (81.3 vs. 176 per 10,000 person-years), with an aHR of 0.39 (95 % CI = 0.29-0.54). The likelihood of developing pulmonary fibrosis was 92 times higher in the PM/DM groups combined than in comparisons (37.9 vs. 0.41 per 10,000 person-years; aHR 84.0 (95 % CI = 49.5-143). The incidence was 1.44-fold higher in patients with PM than in those with DM (46.1 vs. 32.0 per 10,000 person-years), but the difference was not significant. Further analysis showed that in 2452 patients with myositis without pulmonary fibrosis, 234 (9.5 %) had cancer, whereas no cancer was identified in 67 patients with pulmonary fibrosis (p = 0.019). Conclusion: Patients with PM and DM are at great risk of developing cancer and pulmonary fibrosis. Patients who develop pulmonary fibrosis might be at low risk of developing cancer. The complexity of cancer risk interplaying between patients with and without pulmonary fibrosis has clinical relevance and deserves further investigation. Patients who are free of pulmonary fibrosis deserve close monitoring to reduce subsequent cancer risk.

Public Health Youth Ambassador Program: Educating and Empowering the Next Generation of Public Health Leaders to Build Thriving Communities.

Through a collaboration among Fairfax County Health Department (FCHD), Fairfax County Public Schools (FCPS), Morehouse School of Medicine (MSM), George Mason University College of Public Health, federally qualified health centers, hospital systems, non-profits, and other agencies, this initiative targets underserved high school students as a way to increase diversity among community health professionals, build generational health, and provide participants with tools to enhance their post-secondary educational and career opportunities.

AD plasma biomarkers are stable for an extended period at -20°C: implications for resource-constrained environments.

Standard procedures for measuring Alzheimer's disease (AD) plasma biomarkers include storage at -80°C. This is challenging in countries lacking research infrastructure, such -80°C freezer. To investigate stability of AD biomarkers from plasma stored at -20°C, we compared aliquots stored at -80°C and others at -20°C for two, four, six, fifteen, and thirty-five weeks. pTau181, Aß42, Aß40, NfL, and GFAP were measured for each timepoint. pTau181 and Aß42/Aß40 ratios showed minimal variation for up to 15 weeks. NfL and GFAP had higher variability. This finding of 15-week stability at -20°C enables greater participation in AD biomarker studies in resource constrained environments.

Multi-omic analysis of SDHB-deficient pheochromocytomas and paragangliomas identifies metastasis and treatment-related molecular profiles.

Hereditary SDHB-mutant pheochromocytomas (PC) and paragangliomas (PG) are rare tumours with a high propensity to metastasize although their clinical behaviour is unpredictable. To characterize the genomic landscape of these tumours and identify metastasis biomarkers, we performed multi-omic analysis on 94 tumours from 79 patients using seven molecular methods. Sympathetic (chromaffin cell) and parasympathetic (non-chromaffin cell) PCPG had distinct molecular profiles reflecting their cell-of-origin and biochemical profile. TERT and ATRX-alterations were associated with metastatic PCPG and these tumours had an increased mutation load, and distinct transcriptional and telomeric features. Most PCPG had quiet genomes with some rare co-operative driver events observed, including EPAS1/HIF-2α mutations. Two mechanisms of acquired resistance to DNA alkylating chemotherapies were also detected - MGMT overexpression and mismatch repair-deficiency causing hypermutation. Our comprehensive multi-omic analysis of SDHB-mutant PCPG therefore identified features of metastatic disease and treatment response, expanding our understanding of these rare neuroendocrine tumours.

Pregnancy-related maternal mortality in the state of Georgia: Timing and causes of death.

BACKGROUND: The maternal mortality rate in the United States is high and disparities among non-Hispanic White and non-Hispanic Black women remain. In the State of Georgia, the pregnancy-related death rate is among the worst in the nation. OBJECTIVE: To examine current pregnancy-related deaths in the State of Georgia using measures of timing and cause-specific mortality across maternal sociodemographic characteristics. DESIGN: This cross-sectional study of pregnancy-related deaths in Georgia was based on 2016-2019 maternal mortality data obtained from the Georgia Department of Public Health. METHODS: Our study analysis involved complete-case data of maternal deaths identified as pregnancy-related deaths (n = 129). Statistical analyses included two distinct population-level measures: (a) timing (i.e. during pregnancy, 0 to 60 days, 61 to 180 days, and 181 to 365 days postpartum) and (b) cause-specific deaths patterned by sociodemographic groups of women and by rural and urban county of residence. Categorical variables were compared using the Chi square or Fisher's exact test and presented as numbers and percentages. A post hoc power analysis was conducted to inform whether there was sufficient power to detect statistically significant effects given available sample sizes. RESULTS: Among a total of 129 pregnancy-related deaths, 30 (23.3%) deaths occurred during pregnancy and 63 (48.8%) deaths occurred within the first 60 days postpartum. Pregnancy-related deaths were disproportionally common among non-Hispanic Black, 25 to 34 years old, and poorly educated women. Three leading underlying causes, cardiomyopathy (22.7%), hemorrhage (21.6%), and cardiovascular or coronary disease (20.4%), accounted for about 65% of all pregnancy-related deaths. Mental health conditions were common causes of death among non-Hispanic White women during pregnancy and in late postpartum. CONCLUSION: Continued monitoring, collecting and analyzing reliable data will help identify root causes and find ways to eliminate the disproportionate burden of pregnancy-related deaths in the State of Georgia.

Synthesis and Properties of the Helium Clathrate and Defect Perovskite [He2-x □ x ][CaNb]F6.

The defect double perovskite [He2-x □ x ][CaNb]F6, with helium on its A-site, can be prepared by the insertion of helium into ReO3-type CaNbF6 at high pressure. Upon cooling from 300 to 100 K under 0.4 GPa helium, ∼60% of the A-sites become occupied. Helium uptake was quantified by both neutron powder diffraction and gas insertion and release measurements. After the conversion of gauge pressure to fugacity, the uptake of helium by CaNbF6 can be described by a Langmuir isotherm. The enthalpy of absorption for helium in [He2-x □ x ][CaNb]F6 is estimated to be ∼+3(1) kJ mol-1, implying that its formation is entropically favored. Helium is able to diffuse through the material on a time scale of minutes at temperatures down to ∼150 K but is trapped at 100 K and below. The insertion of helium into CaNbF6 reduces the magnitude of its negative thermal expansion, increases the bulk modulus, and modifies its phase behavior. On compressing pristine CaNbF6, at 50 and 100 K, a cubic (Fm3̅m) to rhombohedral (R3̅) phase transition was observed at <0.20 GPa. However, a helium-containing sample remained cubic at 0.4 GPa and 50 K. CaNbF6, compressed in helium at room temperature, remained cubic to >3.7 GPa, the limit of our X-ray diffraction measurements, in contrast to prior reports that upon compression in a nonpenetrating medium, a phase transition is detected at ∼0.4 GPa.

Development and Validation of a US HAE-C1INH Quality of Life Instrument.

BACKGROUND: Hereditary angioedema (HAE) attacks are unpredictable, cause a substantial and enduring burden of illness, and are potentially fatal. Due to issues unique to the US healthcare system, there is a need for a US-validated HAE-specific Quality of Life (QoL) instrument. OBJECTIVE: To develop and validate a US HAE-specific QoL instrument, following FDA guidelines and established methodologies. METHODS: We generated 41 QoL-related items likely relevant to US HAE-C1INH patients and performed a 10-patient pilot study to refine the question-wording. 415 HAE C1-inhibitor (C1INH) deficiency U.S. patients completed the initial 41-item instrument online, providing the data for item reduction, factor analysis, and the assessment of validity and reliability. We used multiple linear regression to identify the drivers of total and domain scores. Convergent validity analysis assessed the extent to which the HAE-C1INH-QoL is theoretically related to the angioedema-QoL (AE-QoL). RESULTS: Item reduction and factor analysis yielded a final instrument of 31 items across five domains, and the assessment analysis showed that the HAE-C1INH-QoL is valid and reliable. Attack frequency and severity were statistically significant factors influencing total and domain scores. Correlation analysis of the two instruments indicated that 8 items of the HAE-C1INH-QoL were not included or well-described in the AE-QoL. CONCLUSION: The HAE-C1INH-QoL is the first HAE-specific QoL tool validated in the US. Compared to the AE-QoL, the items in our instrument are more relevant to US HAE patients.

Estimating Octanol-Water Partition Coefficients of Novel Brominated Flame Retardants by Reversed-Phase High-Performance Liquid Chromatography and Computational Models.

Legacy brominated flame retardants, including polybrominated diphenyl ethers (PBDEs), have been classified as persistent organic pollutants and replaced with novel brominated flame retardants (NBFRs). The octanol-water partition coefficients (log KOW) of NBFRs have been computationally estimated, but the log KOW values provided by these methods can differ by 1 to 3 orders of magnitude. Given the importance of this parameter in fate and toxicity models, we indirectly measured the log KOW values of eight NBFRs by their capacity factor (k') on a reversed-phase high-performance liquid chromatography (HPLC) C18 column by isocratic elution and compared these measured values with those estimated by nine computational models. Log KOW values were obtained for the NBFRs 1,2-bis(2,4,6-tribromophenoxy) ethane, pentabromobenzene, pentabromoethylbenzene, pentabromotoluene, 2-ethylhexyl 2,3,4,5-tetrabromobenzoate, allyl 2,4,6-tribromophenylether, 2,3-dibromopropyl-2,4,6-tribromophenyl ether, and bis(2-ethylhexyl) tetrabromophthalate. A training set of phthalates, polychlorinated biphenyls, PBDEs, and halogenated benzenes were chosen to obtain the log k'-log KOW calibration for the NBFRs. The computational models KowWIN, XLogP3, EAS-E Suite, COSMOtherm, DirectML, and Abraham polyparameter linear free energy relationships all predicted the log KOW values of the calibration compounds to within 1 order of magnitude without significant bias. The median of these models predicted log KOW values for the calibration compounds that were close to those known in the literature with root mean square error (RMSE) = 0.224 and for the NBFRs that were close to those measured by HPLC (RMSE = 0.334). Environ Toxicol Chem 2024;00:1-10. © 2024 SETAC.