Telomere and subtelomere high polymorphism might contribute to the specificity of homologous recognition and pairing during meiosis in barley in the context of breeding.

Barley (Hordeum vulgare) is one of the most popular cereal crops globally. Although it is a diploid species, (2n = 2x = 14) the study of its genome organization is necessary in the framework of plant breeding since barley is often used in crosses with other cereals like wheat to provide them with advantageous characters. We already have an extensive knowledge on different stages of the meiosis, the cell division to generate the gametes in species with sexual reproduction, such as the formation of the synaptonemal complex, recombination, and chromosome segregation. But meiosis really starts with the identification of homologous chromosomes and pairing initiation, and it is still unclear how chromosomes exactly choose a partner to appropriately pair for additional recombination and segregation. In this work we present an exhaustive molecular analysis of both telomeres and subtelomeres of barley chromosome arms 2H-L, 3H-L and 5H-L. As expected, the analysis of multiple features, including transposable elements, repeats, GC content, predicted CpG islands, recombination hotspots, G4 quadruplexes, genes and targeted sequence motifs for key DNA-binding proteins, revealed a high degree of variability both in telomeres and subtelomeres. The molecular basis for the specificity of homologous recognition and pairing occurring in the early chromosomal interactions at the start of meiosis in barley may be provided by these polymorphisms. A more relevant role of telomeres and most distal part of subtelomeres is suggested.

Structure determination in a new type of amorphous molecular solids with different nonlinear optical properties: a comparative structural analysis.

The microscopic structures of two amorphous molecular solids with extremely nonlinear optical properties have been studied. They consist of organotetrel chalcogenide clusters with the chemical formula [(RSn)4S6]. The basic molecular building blocks are adamantane-like {Sn4S6} cores with organic ligands R attached to the Sn atoms. While the material equipped with R=naphthyl generates frequency doubling upon irradiation with a simple infrared laser diode, the material decorated with R=phenyl responds by emitting brilliant white light. The structural differences were investigated using x-ray scattering and extended x-ray absorption fine structure combined with molecular Reverse Monte Carlo. Transmission electron microscopy and scanning precession electron diffraction were used to examine structural differences from mesoscopic down to microscopic scales. Characteristic differences were found on all scales. While close core-to-core distances between {Sn4S6} cluster cores and molecular distortions are found in the white light emitting material, undistorted molecules and significantly larger core distances characterize the material showing frequency doubling. Here however, results of scanning precession electron diffraction reveal the formation of nanocrystalline structures in the amorphous matrix, which we identify as cause for the suppression of white light emission.

Bringing Machine-Learning Enhanced Quantum Chemistry and Microwave Spectroscopy to Conformational Landscape Exploration: the Paradigmatic Case of 4-Fluoro-Threonine.

A combined experimental and theoretical study has been carried out on 4-fluoro-threonine, the only naturally occurring fluorinated amino acid. Fluorination of the methyl group significantly increases the conformational complexity with respect to the parent amino acid threonine. The conformational landscape has been characterized in great detail, with special attention given to the inter-conversion pathways between different conformers. This led to the identification of 13 stable low-energy minima. The equilibrium population of so many conformers produces a very complicated and congested rotational spectrum that could be assigned through a strategy that combines several levels of quantum chemical calculations with the principles of machine learning. Twelve conformers out of 13 could be experimentally characterized. The results obtained from the analysis of the intra-molecular interactions can be exploited to accurately model fluorine-substitution effects in biomolecules.

Prognostic Value of Cardiac MRI and FDG PET in Cardiac Sarcoidosis: A Systematic Review and Meta-Analysis.

Background There is no consensus regarding the relative prognostic value of cardiac MRI and fluorodeoxyglucose (FDG) PET in cardiac sarcoidosis. Purpose To perform a systematic review and meta-analysis of the prognostic value of cardiac MRI and FDG PET for major adverse cardiac events (MACE) in cardiac sarcoidosis. Materials and Methods In this systematic review, MEDLINE, Ovid Epub, CENTRAL, Embase, Emcare, and Scopus were searched from inception until January 2022. Studies that evaluated the prognostic value of cardiac MRI or FDG PET in adults with cardiac sarcoidosis were included. The primary outcome of MACE was assessed as a composite including death, ventricular arrhythmia, and heart failure hospitalization. Summary metrics were obtained using random-effects meta-analysis. Meta-regression was used to assess covariates. Risk of bias was assessed using the Quality in Prognostic Studies, or QUIPS, tool. Results Thirty-seven studies were included (3489 patients with mean follow-up of 3.1 years ± 1.5 [SD]); 29 studies evaluated MRI (2931 patients) and 17 evaluated FDG PET (1243 patients). Five studies directly compared MRI and PET in the same patients (276 patients). Left ventricular late gadolinium enhancement (LGE) at MRI and FDG uptake at PET were both predictive of MACE (odds ratio [OR], 8.0 [95% CI: 4.3, 15.0] [P < .001] and 2.1 [95% CI: 1.4, 3.2] [P < .001], respectively). At meta-regression, results varied by modality (P = .006). LGE (OR, 10.4 [95% CI: 3.5, 30.5]; P < .001) was also predictive of MACE when restricted to studies with direct comparison, whereas FDG uptake (OR, 1.9 [95% CI: 0.82, 4.4]; P = .13) was not. Right ventricular LGE and FDG uptake were also associated with MACE (OR, 13.1 [95% CI: 5.2, 33] [P < .001] and 4.1 [95% CI: 1.9, 8.9] [P < .001], respectively). Thirty-two studies were at risk for bias. Conclusion Left and right ventricular late gadolinium enhancement at cardiac MRI and fluorodeoxyglucose uptake at PET were predictive of major adverse cardiac events in cardiac sarcoidosis. Limitations include few studies with direct comparison and risk of bias. Systematic review registration no. CRD42021214776 (PROSPERO) © RSNA, 2023 Supplemental material is available for this article.

Impact of Adjunctive Pharmacotherapy With Intragastric Balloons for the Treatment of Obesity.

BACKGROUND: We conducted this study to compare the weight loss outcome of intragastric balloons (IGBs) in conjunction with pharmacotherapy vs IGB and intensive lifestyle changes alone. METHODS: This was a multicenter, non-randomized, retrospective study involving 4 academic hospitals. Patients underwent IGB placement with or without concomitant anti-obesity pharmacotherapy. The primary outcome was percent total weight loss (TBWL) after IGB placement at 6 and 12 months. RESULTS: This study included 102 patients, with 23 patients (mean age 46.6 years, 82.6% female) treated with IGB/pharmacotherapy and 79 patients (mean age 46.0 years, 88.6% female) treated with IGB/lifestyle modifications. Patients had a 100% follow-up rate at 6 and 12 months. At 6 months following IGB placement, both groups achieved a similar %TBWL. At 12 months, %TBWL was greater in the IGB/pharmacotherapy group (12.6% ± 1.2 vs 9.7% ± 0.7, P = .04). 65.2% of patients achieved ≥10% TBWL at 12 months in the IGB/pharmacotherapy group, compared to 38.0% in the IGB/lifestyle group (P < .05). The proportion of patients that achieved ≥15% weight loss at 12 months was also significantly different between the IGB/pharmacotherapy and IGB/lifestyle groups (30.4% vs 20.3%, P < .05). DISCUSSION: IGB with concomitant use of pharmacotherapy did not improve weight loss while the IGB was in place compared to IGB and lifestyle changes. However, patients receiving IGB with pharmacotherapy did have greater weight loss and diminished weight regain after balloon removal compared to those receiving just IGB and lifestyle changes.

Molecular characterization of Giardia lamblia and risk factors for giardiasis among immunocompromised patients in southern Brazil.

Acute Giardia infections often cause diarrhea and stomach upset. Chronic infections can lead to malnutrition, micronutrient deficiencies, malabsorption and weight loss. This study assessed the prevalence of G. lambia infection and assessed associated risk factors among immunocompomised patients undergoing chemotherapeutic treatment in southern Brazil. A total of 110 immunocompromised patients in Pelotas, RS, Brazil, consented to participate in this study and were recruited. Socioeconomic and epidemiological profile of patients was collected by questionnaire. The prevalence for Giardia were determined through microscopy by the centrifugation-flotation technique using stool samples of every patient. In addition, the genetic characterization of the parasite was carried out by amplifying and sequencing the glutamate dehydrogenase (gdh) gene. By microscopy, the prevalence of giardiasis was 17.3% (19/110). Furthermore, the DNA sequences revealed that 7 (36.8%) out of 19 isolates belonged to assemblage B, while 6 of them (31.6%) belonged to assemblage C, 5 (26.3%) to assemblage A and 1 (5.3%) to assemblage D. Risk factors (p ≤ 0.05) for giardiasis were schooling level (OR=8.0 (1.02 - 62.91) sharing a house with more than three people (OR=14.1 (3.77 - 52.51), water sources (OR=38.9 (10.4 - 145.7), sewage treatment (OR=14.2 (3.1 - 65.5), waste destination (OR=7.44 (2.0 - 27.3), owning pets (OR=4.6 (1.0 - 21.2) and cultivating a vegetable garden (OR=4.2 (1.3 - 13.6). The prevalence of G. lamblia in immunocompromised patients was considered elevate with the identification of four assemblage of the parasite (A, B, C and D).

Unveiling the Shape of N-Acetylgalactosamine: A Cancer-Associated Sugar Derivative.

In the present work, we report the first rotational study of N-acetylgalactosamine, a cancer-associated sugar derivative, by means of high-resolution rotational spectroscopy. Two different conformers have been conclusively characterized using broadband Fourier transform microwave spectroscopy coupled with a laser ablation vaporization system. Additionally, we performed a comprehensive analysis of the intramolecular interactions that govern these structures, which allowed us to both characterize the existence of intramolecular hydrogen bond networks that drive the intrinsic conformation panorama of N-acetylgalactosamine and further rationalize the biological role of this aminosugar derivative as part of the Tn antigen.

Impact of refitted race-free eGFR formula on obesity pharmacotherapy options.

OBJECTIVE: Recent changes to the Chronic Kidney Disease Epidemiology Collaboration estimated glomerular filtration rate (eGFR) formula (2021 CKD-EPI) removed race from the 2009 formula, increasing the number of Black people classified as having CKD, but these changes may impact eligibility and/or dosing for antiobesity medications. This study estimated the number of people with obesity nationwide who might have pharmacotherapy options impacted by the new formula. METHODS: Using National Health and Nutrition Examination Survey (NHANES) cohort study data, the number of people eligible for antiobesity medication was estimated, and the number who would require a dosage reduction or would no longer be eligible for specific medications based on the new eGFR formula was also estimated. RESULTS: Among 16,412,571 Black and 109,654,751 non-Black people eligible for antiobesity medication, 911,336 (6.1%) Black and 6,925,492 (6.6%) non-Black people had ≥CKD stage 3 by the 2009 CKD-EPI formula. Applying the 2021 CKD-EPI formula, 1,260,969 (8.5%) Black people and 4,989,919 (4.7%) non-Black people had ≥CKD stage 3. For medications requiring renal adjustment, the number of Black people who would require a lower dose or be precluded from using a medication increased by 24.7% to 50.2%. CONCLUSIONS: These findings highlight the importance of measuring-rather than estimating-GFR in Black people with CKD when considering many antiobesity pharmacotherapy options.

Understanding the abundance of the rare sugar ß-D-allose.

The conformational landscape of ß-D-allose, a rare sugar, was investigated using laser ablation in combination with high-resolution rotational spectroscopy. Altogether, three species are identified, exhibiting a counter-clockwise intramolecular hydrogen bond network. The effect of epimerization on the main aldohexose is also studied and, despite the main conformers being very similar, the position of the hydroxyl groups in allose allows the formation of considerably stronger intramolecular hydrogen bonds than in glucose, and this could explain the low abundance of ß-D-allose in Nature.

The Use of Brexpiprazole Combined With a Stimulant in Adults With Treatment-Resistant Attention-Deficit/Hyperactivity Disorder.

BACKGROUND: This is the first controlled pharmacologic study in either adults or children with uncomplicated, treatment-resistant attention-deficit/hyperactivity disorder (ADHD). This study augmented stimulant therapy with the atypical antipsychotic brexpiprazole. The Food and Drug Administration preapproved primary outcome measure (Conners' Adult ADHD Rating Scale [CAARS]) showed no drug-placebo differences. Often studies showing no efficacy on the prestudy, defined primary outcome variable go unpublished. While this is decried, publishing studies with equivocal results remains rare. This reanalysis highlights trends in secondary measures having implications for treatment and research regarding treatment resistant ADHD. METHODS: Initially, 559 stimulant-naive and 174 prior stimulant nonresponders received methylphenidate osmotic-release oral system, dexmethylphenidate hydrochloride, lisdexamfetamine, or mixed amphetamine salts. After 5 weeks, 168 stimulant-naive patients and 68 prior stimulant nonresponders who failed treatment were randomized to brexpiprazole or placebo in a 2:1 ratio while the remaining were on the stimulant. Outcome was measured with the CAARS, Montgomery-Asberg Depression Rating Scale, Beck Depression Inventory, Clinical Global Impression, and the Wender-Reimherr Adult Attention Deficit Disorder Scale (WRAADDS). The WRAADDS contains 2 factors: attention and emotional dysregulation. RESULTS: Stimulant-naive patients showed no improvement with adjunctive brexpiprazole. Prior stimulant nonresponders displayed no brexpiprazole effect on the CAARS, Montgomery-Asberg Depression Rating Scale, or Beck Depression Inventory. In contrast, the WRAADDS detected a trend in treatment benefit, primarily through emotional dysregulation symptoms. Adverse effects on brexpiprazole and placebo were equivalent. CONCLUSIONS: Brexpiprazole might be effective in ADHD adults who are nonresponders to 2 or more stimulants. Future trials in treatment-resistant ADHD should use a 1:1 randomization and use a measure of ADHD symptoms that includes emotional dysregulation.

The Ham-D is not Hamilton's Depression Scale.

Introduction: This article will demonstrate that the most widely used versions of the Hamilton Rating Scale for Depression (HAM-D) used in randomized clinical trials, the Guy 1976 HAM-D1 and the SIGH-D,2 have response options that deviate sharply from Max Hamilton's 19603 and 19674 guidelines. For example, difficulty in concentration, one of the diagnostic criteria for a Major Depressive Episode according to the Diagnostic and Statistical Manual of Mental Disorders (DSM) since 1980, in editions III, IV, IV-TR and 5,5 is something that Hamilton wrote should be measured in his scale, yet it is not measured in either of the presently used HAM-Ds. Method: A review was conducted of the four key papers related to the development of the Hamilton Rating Scale for Depression: the 1960 and 1967 papers by Max Hamilton; the HAM-D chapter in the 1976 ECDEU Assessment Manual for Psychopharmacology edited by William Guy; and the 1988 article on the Structured Interview Guide for the HAM-D (SIGH-D) by Janet Williams. Additionally, the Janet Williams updated 2013 SIGH-D6 is also reviewed. Results: When comparing the HAM-D and the SIGH-D with the gold standard Hamilton guidelines from his 1960 and 1967 articles, 13 of the 17 items contain significant errors. Conclusion: Significant differences between the currently used HAM-Ds and the guidelines set forth by Max Hamilton in 1960 and 1967 will be demonstrated. These discrepancies may produce inconsistencies in administration and scoring, leading to unreliable measurements of subjects' and patients' depressive symptoms and unreliable measurement of their progress over time.

The eight structures of caffeic acid: a jet-cooled laser ablated rotational study.

This work reports a complete conformational analysis of caffeic acid, an exceptionally versatile pharmacophore, using laser ablation chirped-pulse Fourier transform microwave spectroscopy. The whole conformational space consisting of eight distinct species has been fully deciphered based on the trend of the rotational constants supported by theoretical computations. We show how rotational spectroscopy can be confidently used to distinguish between conformers even when the structural differences are minimal, such as those involved in the conformational panorama of caffeic acid. Additionally, the structural information here provided, such as the planarity observed in all the conformers, could help to elucidate the mechanisms underlying the biological and pharmacological activity of hydroxycinnamic acids.

Caracterización de pacientes hospitalizados con sospecha de disfagia en el Hospital San Camilo de San Felipe, Chile / Characterization of hospitalized patients with suspected dysphagia at Hospital San Camilo, San Felipe

Resumen Introducción: El trastorno de la deglución, se denomina disfagia y presenta como complicaciones fundamentales la deshidratación, desnutrición y neumonía por aspiración, situaciones que condicionan desfavorablemente el estado de salud, incrementando la morbimortalidad. En Chile, existen escasas publicaciones a la fecha que den cuenta de antecedentes clínicos que permitan describir a los pacientes con sospecha de disfagia. Objetivo: Describir las características clínicas de pacientes hospitalizados con sospecha de disfagia en el Hospital San Camilo de San Felipe, Chile. Material y Método: Estudio descriptivo de 767 registros de pacientes, entre los años 2017 y 2019. Se revisó información demográfica y antecedentes clínicos. Para variables cualitativas, se utilizaron proporciones y distribuciones frecuenciales, para variables cuantitativas, se usaron medidas de tendencia central. Resultados: El 58,54% de los pacientes era de sexo masculino y el 79,4% correspondió a personas mayores (79,4%). Las patologías neurológicas representaron el diagnóstico de ingreso más frecuente (61,93%). El 14,73% presentó antecedentes de intubación endotraqueal, el 8,34% tenía traqueostomía y el 84,09% era edéntulo parcial o total. En la evaluación con alimentos, las degluciones múltiples y la presencia de tos correspondieron a las alteraciones de eficacia y seguridad más frecuentes. En el 82,01% se diagnosticó disfagia y la mayoría de etiología neurogénica (68,45%). Conclusión: El presente estudio permitió conocer las características clínicas de los pacientes con sospecha de disfagia hospitalizados. En este contexto los pacientes extubados, traqueostomizados y las personas mayores con trastornos neurológicos o patologías respiratorias se presentan como potenciales candidatos para la evaluación de deglución.

Abstract Introduction: The swallowing disorder is called dysphagia and presents complications such as dehydration, malnutrition and aspiration pneumonia, situations that unfavorably condition the state of health, increasing morbidity and mortality. In Chile, there are few publications to date that provide an account of clinical history that allow the description of patients with suspected dysphagia. Aim: To describe the clinical characteristics of hospitalized patients with suspected dysphagia at Hospital San Camilo de San Felipe, Chile. Material and Method: Descriptive study of 767 patient records, between the years 2017 and 2019. Demographic information and clinical history were reviewed. For qualitative variables, proportions and frequency distributions were used, for quantitative variables, measures of central tendency were used. Results: 58.54% of the patients were male and 79.4% corresponded to elderly people (79.4%). Neurological pathologies represented the most frequent admission diagnosis (61.93%). 14.73% had a history of endotracheal intubation, 8.34% had a tracheostomy, and 84.09% were partial or total edentulous. In the evaluation with food, multiple swallows and the presence of cough corresponded to the most frequent alterations in efficacy and safety. In 82.01%, dysphagia was diagnosed and the majority of neurogenic etiology (68.45%). Conclusion: The present study allowed us to describe the clinical characteristics of hospitalized patients with suspected dysphagia. In this context, extubated, tracheostomized patients and the elderly with neurological disorders or respiratory pathologies are presented as potential candidates for swallowing evaluation.

A wafer-scale fabrication method for three-dimensional plasmonic hollow nanopillars.

Access to nanofabrication strategies for crafting three-dimensional plasmonic structures is limited. In this work, a fabrication strategy to produce 3D plasmonic hollow nanopillars (HNPs) using Talbot lithography and I-line photolithography is introduced. This method is named subtractive hybrid lithography (SHL), and permits intermixed usage of nano-and-macroscale patterns. Sputter-redeposition of gold (Au) on the SHL resist pattern yields large areas of dense periodic Au-HNPs. These Au-HNPs are arranged in a square unit cell with a 250 nm pitch. The carefully controlled fabrication process resulted in Au-HNPs with nanoscale dimensions over the Au-HNP dimensions such as an 80 ± 2 nm thick solid base with a 133 ± 4 nm diameter, and a 170 ± 10 nm high nano-rim with a 14 ± 3 nm sidewall rim-thickness. The plasmonic optical response is assessed with FDTD-modeling and reveals that the highest field enhancement is at the top of the hollow nanopillar rim. The modeled field enhancement factor (EF) is compared to the experimental analytical field enhancement factor, which shows to pair up with ca. 103 < EF < 104 and ca. 103 < EF < 105 for excitation wavelengths of 633 and 785 nm. From a broader perspective, our results can stimulate the use of Au-HNPs in the fields of plasmonic sensors and spectroscopy.

Rotational spectroscopic study and astronomical search for propiolamide in Sgr B2(N).

CONTEXT: For all the amides detected in the interstellar medium (ISM), the corresponding nitriles or isonitriles have also been detected in the ISM, some of which have relatively high abundances. Among the abundant nitriles for which the corresponding amide has not yet been detected is cyanoacetylene (HCCCN), whose amide counterpart is propiolamide (HCCC(O)NH2). AIMS: With the aim of supporting searches for this amide in the ISM, we provide a complete rotational study of propiolamide from 6 GHz to 440 GHz. METHODS: Time-domain Fourier transform microwave (FTMW) spectroscopy under supersonic expansion conditions between 6 GHz and 18 GHz was used to accurately measure and analyze ground-state rotational transitions with resolved hyperfine structure arising from nuclear quadrupole coupling interactions of the 14N nucleus. We combined this technique with the frequency-domain room-temperature millimeter wave and submillimeter wave spectroscopies from 75 GHz to 440 GHz in order to record and assign the rotational spectra in the ground state and in the low-lying excited vibrational states. We used the ReMoCA spectral line survey performed with the Atacama Large Millimeter/submillimeter Array toward the star-forming region Sgr B2(N) to search for propiolamide. RESULTS: We identified and measured more than 5500 distinct frequency lines of propiolamide in the laboratory. These lines were fitted using an effective semi-rigid rotor Hamiltonian with nuclear quadrupole coupling interactions taken into consideration. We obtained accurate sets of spectroscopic parameters for the ground state and the three low-lying excited vibrational states. We report the nondetection of propiolamide toward the hot cores Sgr B2(N1S) and Sgr B2(N2). We find that propiolamide is at least 50 and 13 times less abundant than acetamide in Sgr B2(N1S) and Sgr B2(N2), respectively, indicating that the abundance difference between both amides is more pronounced by at least a factor of 8 and 2, respectively, than for their corresponding nitriles. CONCLUSIONS: Although propiolamide has yet to be included in astrochemical modeling networks, the observed upper limit to the ratio of propiolamide to acetamide seems consistent with the ratios of related species as determined from past simulations. The comprehensive spectroscopic data presented in this paper will aid future astronomical searches.

Metformin-induced weight loss in patients with or without type 2 diabetes/prediabetes: A retrospective cohort study.

It is unknown whether weight loss outcomes differ with metformin monotherapy in patients with obesity with or without type 2 diabetes (T2DM)/prediabetes (PreDM). In this retrospective study, 6- or 12-month weight loss outcomes were compared in 222 patients with or without T2DM/preDM who completed metformin monotherapy. Average weight loss was similar between groups, euglycemic vs. T2DM/preDM (6 months: 6.5 [6.0%] vs. 6.5 [6.1%] p = 0.97; 12 months: 7.4 [6.2%] vs. 7.3 [7.7%], p = 0.92). Categorical weight losses (≥5% and ≥10% of baseline weight) were also similar. Comparable clinically significant weight loss was achieved with metformin monotherapy in patients with obesity with or without T2DM/PreDM.

Best Practices in the Management of Overweight and Obesity.

Obesity is a chronic disease caused by dysregulated energy homeostasis pathways that encourage the accumulation of adiposity, which in turn results in the development or exacerbation of weight-related comorbidities. Treatment of obesity relies on a foundation of lifestyle modification; weight loss pharmacotherapy, bariatric surgery and devices are additional tools to help patients achieve their health goals. Appropriate management of patients with obesity provides multiple metabolic benefits beyond weight loss.

Temporal trends in radiometrically dated sediment cores from English lakes show polybrominated diphenyl ethers correlate with brominated but not mixed bromo/chloro dioxins and furans.

This paper reports concentrations between ~1950 and present, of polybrominated diphenyl ethers (PBDEs) and polybrominated dibenzo-p-dioxins and furans (PBDD/Fs), in radiometrically-dated sediment cores from three English lakes. Mixed bromo/chloro dibenzo-p-dioxins and furans (PXDD/Fs) were measured in two of the same lakes. Concentrations of PXDD/Fs decreased over time to the present. To our knowledge, this is the first report of temporal trends of PXDD/Fs in the environment. In contrast, concentrations of PBDEs increased towards the present and were significantly correlated (R = 0.88-0.98; p < 0.05) with concentrations of PBDFs in all three lakes. These observations suggest that the sources of PXDD/Fs are not related to PBDEs and differ from those of PBDFs. We also report for the first time the presence of octabromodibenzofuran (OBDF) in the two most recent core slices at one lake. The source of OBDF in these samples is unclear. While OBDF has been reported previously as a significant contaminant of some commercial formulations of Deca-BDE, it is also present in Octa-BDE products and in emissions from a variety of combustion activities. Overall, while the positive correlation between PBDEs and PBDFs suggests increased use of PBDEs has contributed substantially to environmental contamination with PBDFs; examination of PBDF homologue patterns implies emissions from combustion activities are likely also important.