Closing the Organofluorine Mass Balance in Marine Mammals Using Suspect Screening and Machine Learning-Based Quantification.

High-resolution mass spectrometry (HRMS)-based suspect and nontarget screening has identified a growing number of novel per- and polyfluoroalkyl substances (PFASs) in the environment. However, without analytical standards, the fraction of overall PFAS exposure accounted for by these suspects remains ambiguous. Fortunately, recent developments in ionization efficiency (IE) prediction using machine learning offer the possibility to quantify suspects lacking analytical standards. In the present work, a gradient boosted tree-based model for predicting log IE in negative mode was trained and then validated using 33 PFAS standards. The root-mean-square errors were 0.79 (for the entire test set) and 0.29 (for the 7 PFASs in the test set) log IE units. Thereafter, the model was applied to samples of liver from pilot whales (n = 5; East Greenland) and white beaked dolphins (n = 5, West Greenland; n = 3, Sweden) which contained a significant fraction (up to 70%) of unidentified organofluorine and 35 unquantified suspect PFASs (confidence level 2-4). IE-based quantification reduced the fraction of unidentified extractable organofluorine to 0-27%, demonstrating the utility of the method for closing the fluorine mass balance in the absence of analytical standards.

Resilience, Well-being, and Empathy Among Private Practice Physicians and Advanced Practice Providers in Texas: A Structural Equation Model Study.

OBJECTIVE: To investigate structural relationships of latent constructs such as occupational wellbeing, resilience, work meaningfulness, and psychological empowerment with affective and cognitive clinical empathy among a community of physicians and advanced practice providers. METHODS: We conducted a cross-sectional observational study. We gathered data by an anonymous self-administered multidimensional questionnaire disseminated electronically between March and May 2016. Participants were physicians and advanced practice providers belonging to the Health Texas Provider Network, a group private practice affiliated with the Baylor Scott and White Health system. We excluded allied health care staff (eg, nurses) and trainees (eg, residents, medical students). We pursued a 3-step strategy: (1) confirmatory factor analysis of a theory-driven measurement model, (2) a modified structural equation model from which pathways with nonsignificant path coefficients were deleted, and (3) multigroup analyses of the modified model. RESULTS: Cognitive empathy was the strongest predictor of affective empathy. We observed modest positive associations of resilience with cognitive and affective empathy and of well-being and meaning with affective but not with cognitive empathy. Resilience, meaning, and psychological empowerment were surprisingly negatively associated with well-being, suggesting diminished self-care among practitioners. Effects of psychological empowerment on empathy and well-being were mediated by resilience and meaning. CONCLUSION: Cognitive empathy directly influenced affective empathy; well-being and meaningfulness exerted direct positive effects on affective but not on cognitive empathy, whereas resilience had direct positive associations with both empathy dimensions. Resilience and meaning manifested direct, negative associations with well-being, revealing clinicians' disproportionate focus on patient care at the expense of self-care.

A young man presenting with encephalopathy and seizures secondary to SARS-CoV-2.

COVID-19 has now emerged from a respiratory illness to a systemic viral illness with multisystem involvement. There is still a lot to learn about this illness as new disease associations with COVID-19 emerge consistently. We present a unique case of a neurological manifestation of a patient with structural brain disease who was COVID-19 positive and developed mental status changes, new-onset seizures and findings suggestive of viral meningitis on lumbar puncture. We also review the literature and discuss our case in the context of the other cases reported. We highlight the value of considering seizures and encephalopathy as one of the presenting features of COVID-19 disease.

IRS Notice 2002-8 clarifies split-dollar life insurance arrangements.

Healthcare organizations that sponsor split-dollar life insurance arrangements for employees need to understand the tax treatment of such arrangements. IRS Notice 2002-8 clarifies this issue. The notice announces the IRS's intention to publish final regulations regarding the taxation of split-dollar life insurance, outlines the expected provisions to be included in the regulations, provides guidance on the value of economic benefit provided under such arrangements, and issues rules for the taxation of arrangements entered into before the publication of final rules.