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Background: Brominated flame retardants (BFRs) are widely utilized to mitigate the flammability of various materials. Previous studies have revealed the impact of BFRs exposure on hormonal disruption and bone metabolism which are closely related to periodontitis. However, it remains unknown the potential relationship between BFRs and periodontitis. This study aimed to explore the association between BFRs exposure and periodontitis in US adults. Methods: The data analyzed in this study were obtained from the National Health and Nutrition Examination Survey (NHANES) 2009–2014. Twelve serum BFRs were quantified using isotope dilution gas chromatography high-resolution mass spectrometry. Univariable and multivariable logistic regression was employed to evaluate the association between serum BFRs and periodontitis. Bayesian kernel machine regression (BKMR) analyses were utilized to assess the association between mixtures of BFRs and periodontitis. Results: A total of 3311 eligible participants were included. Serum BFRs (PBDE-47, PBDE-99, and PBDE-154) were significantly associated with periodontitis, and the odds ratios (ORs) and corresponding 95% confidence intervals(CIs) were 1.15(1.01,1.29), 1.10(1.01,1.20), and 1.12(1.01,1.25), respectively. Notably, these three BFRs were also significantly associated with the severity of periodontitis. Additionally, the BKMR model revealed a significant association between the mixture of all twelve BFRs and periodontitis. Conclusions: This preliminary study suggests a significant association between specific serum BFRs (PBDE-47, PBDE-99, and PBDE-154) and periodontitis and its severity. Further prospective and experimental studies are warranted to validate our findings. [ABSTRACT FROM AUTHOR]

Bone grafting procedures have become increasingly common in the United States, with approximately 500,000 cases occurring each year at a societal cost exceeding $2.4 billion. Recombinant human bone morphogenetic proteins (rhBMPs) are therapeutic agents that have been widely used by orthopedic surgeons to stimulate bone tissue formation alone and when paired with biomaterials. However, significant limitations such as immunogenicity, high production cost, and ectopic bone growth from these therapies remain. Therefore, efforts have been made to discover and repurpose osteoinductive small-molecule therapeutics to promote bone regeneration. Previously, we have demonstrated that a single-dose treatment with the small-molecule forskolin for just 24 h induces osteogenic differentiation of rabbit bone marrow-derived stem cells in vitro, while mitigating adverse side effects attributed with prolonged small-molecule treatment schemes. In this study, we engineered a composite fibrin-PLGA [poly(lactide-co-glycolide)]-sintered microsphere scaffold for the localized, short-term delivery of the osteoinductive small molecule, forskolin. In vitro characterization studies showed that forskolin released out of the fibrin gel within the first 24 h and retained its bioactivity toward osteogenic differentiation of bone marrow-derived stem cells. The forskolin-loaded fibrin-PLGA scaffold was also able to guide bone formation in a 3-mo rabbit radial critical-sized defect model comparable to recombinant human bone morphogenetic protein-2 (rhBMP-2) treatment, as demonstrated through histological and mechanical evaluation, with minimal systemic off-target side effects. Together, these results demonstrate the successful application of an innovative small-molecule treatment approach within long bone critical-sized defects. [ABSTRACT FROM AUTHOR]

The incidence of papillary thyroid cancer (PTC) in the United States has tripled in the past 30 y. Polybrominated diphenyl ethers (PBDEs) are flame retardants that were ubiquitously used over that time period, and exposure to PBDEs has been associated with PTC prevalence. They are potential carcinogens via their induction of reactive oxygen species (ROS) formation and resultant deoxyribonucleic acid (DNA) damage. We sought to determine the effects of PBDE and tris(2-chloroethyl) phosphate (TCEP), another flame retardant implicated in PTC incidence, on thyrocytes in vitro and measure PBDE levels in human thyroid tissue to determine their carcinogenic potential. Nthy-Ori, an immortalized benign human thyroid follicular cell line was used as a model of normal human thyroid. MTT assays were used to measure cell viability after exposure to PBDEs and TCEP. ROS levels and double-stranded and single-stranded DNA breaks were measured to determine genotoxicity. DNA damage response protein levels were measured with immunoblotting. Exposure to 20μM PBDE or TCEP for 48 h had minimal effects on thyrocyte viability. There was no significant increase in intracellular ROS up to 6 h following PBDE or TCEP exposure in thyrocytes; however, cells exposed to PBDE 47 showed evidence of DNA single-stranded and double-stranded breaks. There was a dose-dependent increase in γH2AX levels following exposure to PBDEs 47 and 209 in Nthy-Ori cells but not with TCEP treatment. PBDE 47 and 209 demonstrated genotoxicity but not cytotoxicity in follicular thyrocytes in vitro. Therefore, PBDE 47 and 209 may be carcinogenic in human thyroid cells. [ABSTRACT FROM AUTHOR]

This paper uncovers the socioeconomic and health/lifestyle factors that can explain the differential impact of the coronavirus pandemic on different parts of the United States during the initial outbreak phase of the pandemic. Using a dynamic panel representation of an epidemiological model of disease spread, the paper develops a Vulnerability Index for US counties from the daily reported number of cases over a 20-day period of rapid disease growth. County-level economic, demographic, and health factors are used to explain the differences in the values of this index and thereby the transmission and concentration of the disease across the country. These factors are also used to examine the number of reported deaths. The paper finds that counties with high median income have a high incidence of cases but reported lower deaths. Income inequality, as measured by the Gini coefficient, is found to be associated with more deaths and more cases. The remarkable similarity in the distribution of cases across the country and the distribution of distance-weighted international passengers served by the top international airports is evidence of the spread of the virus by way of international travel. The distributions of age, race and health risk factors such as obesity and diabetes are found to be particularly significant factors in explaining the differences in mortality across counties. Counties with better access to health care, as measured by the number of primary care physicians per capita, have lower deaths, and so do places with more health awareness as measured by flu vaccination prevalence. Environmental health conditions such as the amount of air pollution are found to be associated with counties with higher deaths from the virus. It is hoped that research such as these will help policymakers to develop risk factors for each region of the country to better contain the spread of infectious diseases in the future. [ABSTRACT FROM AUTHOR]

This study investigated the effects of in-package atmospheric dielectric barrier discharge cold plasma (ADCP) treatment on the physicochemical and oral toxicological properties of raw grape tomatoes, as well as the likelihood of salmonellosis infection from consumption treated tomatoes. Grape tomatoes (28 fruits) were packed in commercial polyethylene terephthalate container in two layers and subjected to ADCP. Application of ADCP at 24 kV for 3 min inactivated Salmonella by 3.9 log CFU/tomato. The treatment exerted no impact on the ion leakage, malondialdehyde content, CO 2 generation, and firmness of grape tomatoes. The oral toxicity of ADCP-treated tomatoes was not different from that of untreated tomatoes. The prediction model for risk assessment prognosticated a 94.8% chance occurrence of more than 10 cases of salmonellosis occurring in a year, in association with eating raw grape tomatoes in the United States, compared to a 0.01% chance from the consumption of ADCP-treated tomatoes. The primary factors influencing the number of Salmonella infection cases associated with the consumption of ADCP-treated raw grape tomatoes were the level of Salmonella contamination from processing equipment, storage time by the retailers and consumers, transfer level of the pathogen from the processing equipment, and application of ADCP treatment. These results suggest that ADCP can be used as a method to decontaminate raw grape tomatoes, without altering the quality and toxicological properties, to reduce the incidence of salmonellosis owing to their consumption. • Atmospheric cold plasma treatment (ADCP) was made on packaged 28-grape tomatoes. • ADCP at 24 kV for 3 min inactivated Salmonella on the tomatoes by 3.9 log CFU/tomato. • ADCP did not affect the oral toxicity and quality properties of grape tomatoes. • ADCP lowered the probability of salmonellosis from consumption of grape tomatoes. [ABSTRACT FROM AUTHOR]

Brominated flame retardants (BFRs) are a class of compounds with many persistent, toxic, and bioaccumulative members. BFRs have been widely detected in breast milk, posing health risks for breastfeeding infants. Ten years after the phaseout of polybrominated diphenyl ethers (PBDEs) in the United States, we analyzed breast milk from 50 U.S. mothers for a suite of BFRs to assess current exposures to BFRs and the impact of changing use patterns on levels of PBDEs and current-use compounds in breast milk. Compounds analyzed included 37 PBDEs, 18 bromophenols, and 11 other BFRs. A total of 25 BFRs were detected, including 9 PBDEs, 8 bromophenols, and 8 other BFRs. PBDEs were found in every sample but at concentrations considerably lower than in previous North American samples, with a median ∑PBDE concentration (sum of 9 detected PBDEs) of 15.0 ng/g lipid (range 1.46–1170 ng/g lipid). Analysis of time trends in PBDE concentrations in North American breast milk indicated a significant decline since 2002, with a halving time for ∑PBDE concentrations of 12.2 years; comparison with previous samples from the northwest U.S region showed a 70% decline in median levels. Bromophenols were detected in 88% of samples with a median ∑ 12 bromophenol concentration (sum of 12 detected bromophenols) of 0.996 ng/g lipid and reaching up to 71.1 ng/g lipid. Other BFRs were infrequently detected but concentrations reached up to 278 ng/g lipid. These results represent the first measurement of bromophenols and other replacement flame retardants in breast milk from U.S. mothers. In addition, these results provide data on current PBDE contamination in human milk, as PBDEs were last measured in U.S. breast milk ten years ago. The presence of phased-out PBDEs, bromophenols, and other current-use flame retardants in breast milk reflects ongoing prenatal exposure and increased risk for adverse impacts on infant development. [Display omitted] • Brominated flame retardants (BFRs) were detected in 100% of breast milk samples from U.S. mothers. • Bromophenols were detected for the first time in breast milk from U.S. women. • PBDE levels were 70% lower than samples from the same region taken in 2003. • Presence of BFRs in breast milk raises concerns about harm to infant development. [ABSTRACT FROM AUTHOR]

This manuscript presents new measurement data from milligram-scale thermal decomposition experiments – thermogravimetric analysis (TGA) and microscale combustion calorimetry (MCC) – conducted on stems and leaves (i.e., needles) of six plant species commonly found across the United States. For each fuel, measurement data from TGA experiments was analyzed to determine effective thermal decomposition mechanisms and the associated kinetics of their constituent reactions. Results of this model calibration were compared to standard (i.e., 'generalized') approaches to obtain kinetic parameters available in the literature. MCC experiments were repeated under identical experimental conditions to determine the heats of complete combustion of all gaseous volatiles produced by these vegetative fuels and to validate the decomposition mechanisms and species char yields determined from TGA data. Through a coupled analysis of TGA and MCC measurement data, an estimate of the heats of combustion of the gaseous volatiles produced by individual reaction steps in the fuel's decomposition was also made. Between different fuels, distinct differences were measured in the onset temperature of decomposition, the temperature range of decomposition, the number of apparent reactions, and the peak measured mass loss and heat release rates (as well as the temperatures at which they occur). To analyze the impact of these variations on predictions of wildfire behavior, a modeling study was then conducted in which simulations of wildland fire experiments were repeated using the thermal decomposition mechanisms and heats of combustion determined for each of the fuel species tested in this work. Model-predicted fire spread rate in these simulations varied between 0.34 m s−1 and 0.80 m s−1 demonstrating a notable dependence (up to a factor of 2x) on measured variations in thermal decomposition mechanism and a second-order dependence on the use of either reaction-step-specific or single (global) heats of combustion. [ABSTRACT FROM AUTHOR]