Harmful Exposure Research Articles

A Novel Puff Recording Electronic Nicotine Delivery System for Assessing Naturalistic Puff Topography and Nicotine Consumption During Ad Libitum Use: Ancillary Study.

Assessing the naturalistic puff topography and associated nicotine consumption during e-cigarette use is important as such information will not only unveil how these products are being consumed in real-world conditions, but also enable investigators and regulatory bodies to conduct quantitative, accurate, and realistic harmful exposure and nicotine abuse liability risk assessments based on actual e-cigarette use. Conventional approaches cannot accurately, conveniently, and noninvasively determine e-cigarette puff topography in a natural use environment. Thus, novel technology-enabled systems that do not primarily rely on self-report mechanisms or intrusive measurements to monitor e-cigarette product use behaviors are highly desired. This study aimed to explore and demonstrate the feasibility of a novel puff recording electronic nicotine delivery system (PR-ENDS) device for measuring naturalistic puff topography and estimating nicotine consumption during the ad libitum use of products among smokers and vapers. An ancillary data analysis based on a completed parent study was conducted. The parent study was a 1-way randomized controlled open-label puff topography and nicotine pharmacokinetic assessment carried out in 24 healthy adults (12 smokers and 12 vapers). Participants were assigned a randomized product use sequence of a PR-ENDS device within 5 site visits for both controlled and ad libitum product use sessions. Blood samples were obtained for plasma nicotine analysis, and questionnaires were administered at various time points. During the ad libitum use session, puff topography was measured using a Clinical Research Support System (CReSS) device as a benchmark, as well as the PR-ENDS device with a built-in puff recording feature. There were no significant differences in representative puff topography parameters (number of puffs, total puff duration, and average puff duration) between the PR-ENDS and CReSS devices at the populational level across different device powers, e-liquid nicotine strengths, and flavors. The nicotine consumption estimated by the PR-ENDS device suggested that this device can be employed as a convenient monitoring tool for estimating nicotine use without measuring e-liquid weight loss between puffs. The linear relationship between nicotine consumption estimated by the PR-ENDS device and the pharmacokinetic parameter AUCad lib (plasma concentration-time curve for 1-hour ad libitum use) substantiated the potential of using this device as a pragmatic, noninvasive, and convenient means for estimating nicotine intake in the human body without blood collection. The novel PR-ENDS device was feasible for assessing naturalistic puff topography and estimating nicotine consumption and intake in the human body during ad libitum use. Several key factors can influence users' puff topography, including device power levels, e-liquid nicotine strengths, and flavors. The study results pave the way for further research in the real-time measurement of naturalistic puff topography and puffing behaviors in the real world.

Pollution Characteristics, Source Identification, and Health Risk of Heavy Metals in the Soil-Vegetable System in Two Districts of Bangladesh.

The consequences of climate change, food security, and self-sufficiency goals are driving excessive human activity onto vegetable farms in Bangladesh, and harmful heavy metal exposure is spreading. So, the study assessed the toxic metals (Pb, Cd, and Cr) exposure, characteristics, and human health risk regarding the soil-vegetable system of two distinct locations in Bangladesh using atomic absorption spectrometry. The average concentration of metals in soil and fertilizer/pesticide samples followed the same order (Cr > Pb > Cd), but for vegetable samples, the order was Pb > Cr > Cd, with some extra Pb compared to the World Health Organization (WHO) allowable limit (0.3mg/kg). Low levels of pollution with negligible ecological concerns were predicted for both locations by the soil quality indexing. But industrial influence boosted the Pb content in location B, and common sources (fertilizer/pesticide) for both locations might be responsible for a moderate level of Cd. The toxic metals transferred to vegetables followed the trend of Cd > Pb > Cr. However, the human health risks arising from harmful metals exposure at both locations were ineffective (< 1) in evaluating noncarcinogenic risk patterns through the target hazard quotient (THQ), total THQ, and hazard index (HI). Again, considering probable carcinogenic risk patterns, vegetable consumption with studied exposure levels of toxic metals followed within the acceptable range (between 1.0E-04 and 1.0E-06). Overall, location B is slightly more vulnerable than location A by considering metal exposure, pollution distribution, and risk evaluation in the study area (significant at p < 0.05). So, systematic monitoring and protective measures are required to ensure food safety and sustainable vegetable production.

A science-based agenda for health-protective chemical assessments and decisions: overview and consensus statement

The manufacture and production of industrial chemicals continues to increase, with hundreds of thousands of chemicals and chemical mixtures used worldwide, leading to widespread population exposures and resultant health impacts. Low-wealth communities and communities of color often bear disproportionate burdens of exposure and impact; all compounded by regulatory delays to the detriment of public health. Multiple authoritative bodies and scientific consensus groups have called for actions to prevent harmful exposures via improved policy approaches. We worked across multiple disciplines to develop consensus recommendations for health-protective, scientific approaches to reduce harmful chemical exposures, which can be applied to current US policies governing industrial chemicals and environmental pollutants. This consensus identifies five principles and scientific recommendations for improving how agencies like the US Environmental Protection Agency (EPA) approach and conduct hazard and risk assessment and risk management analyses: (1) the financial burden of data generation for any given chemical on (or to be introduced to) the market should be on the chemical producers that benefit from their production and use; (2) lack of data does not equate to lack of hazard, exposure, or risk; (3) populations at greater risk, including those that are more susceptible or more highly exposed, must be better identified and protected to account for their real-world risks; (4) hazard and risk assessments should not assume existence of a “safe” or “no-risk” level of chemical exposure in the diverse general population; and (5) hazard and risk assessments must evaluate and account for financial conflicts of interest in the body of evidence. While many of these recommendations focus specifically on the EPA, they are general principles for environmental health that could be adopted by any agency or entity engaged in exposure, hazard, and risk assessment. We also detail recommendations for four priority areas in companion papers (exposure assessment methods, human variability assessment, methods for quantifying non-cancer health outcomes, and a framework for defining chemical classes). These recommendations constitute key steps for improved evidence-based environmental health decision-making and public health protection.

Predictive modeling of indoor dust lead concentrations: Sources, risks, and benefits of intervention

Lead (Pb) contamination continues to contribute to world-wide morbidity in all countries, particularly low- and middle-income countries. Despite its continued widespread adverse effects on global populations, particularly children, accurate prediction of elevated household dust Pb and the potential implications of simple, low-cost household interventions at national and global scales have been lacking. A global dataset (∼40 countries, n = 1951) of community sourced household dust samples were used to predict whether indoor dust was elevated in Pb, expanding on recent work in the United States (U.S.). Binned housing age category alone was a significant (p < 0.01) predictor of elevated dust Pb, but only generated effective predictive accuracy for England and Australia (sensitivity of ∼80%), similar to previous results in the U.S. This likely reflects comparable Pb pollution legacies between these three countries, particularly with residential Pb paint. The heterogeneity associated with Pb pollution at a global scale complicates the predictive accuracy of our model, which is lower for countries outside England, the U.S., and Australia. This is likely due to differing environmental Pb regulations, sources, and the paucity of dust samples available outside of these three countries. In England, the U.S., and Australia, simple, low-cost household intervention strategies such as vacuuming and wet mopping could conservatively save 70 billion USD within a four-year period based on our model. Globally, up to 1.68 trillion USD could be saved with improved predictive modeling and primary intervention to reduce harmful exposure to Pb dust sources.

Novel Approaches for the Application of Herbs for Skin Care.

Skin is the largest non-parenchymal organ of the human body. It constitutes a natural barrier against pathogens and harmful environmental exposures and contributes to the human body's homeostasis. Conditions affecting the skin range from infections and injury to autoimmune diseases and cancer. Herbs have been used to treat dermatological conditions for a long time. Traditional approaches to delivering herbs to the skin include ointments, gels, creams, and lotions. However, poor lipophilicity or hydrophilicity in most herbal preparations results in limited bioavailability and poor penetration, restricting their effectiveness. Nanotechnology-based approaches have major potential, showing more promising results in enhancing transdermal penetration than traditional approaches. This review article summarizes such advances and sheds light on future directions in using nanotechnology-based strategies.

Abstract C030: Relationship between the oral microbiome and tobacco-induced DNA damage in African American and White persons who smoke

Abstract Exposure to tobacco smoke chemicals and toxicants may cause unique changes to an individual’s oral microbiome, impacting immuno-inflammatory responses, the metabolism of tobacco smoke carcinogens, and overall health status. In our previous study, HPB-releasing DNA adducts (DNA damage derived from tobacco-specific nitrosamines) were higher in oral cells of African American (AA, n=75) when compared to White (WH, n=71) persons who smoke, even after adjusting for key confounders such as smoking dose. In this study, we examined the relationship between the levels of HPB-releasing DNA adducts and microbiome composition in these individuals. 16S rRNA gene sequencing, targeting the V4 hypervariable region, was performed on DNA isolated from mouthwash samples. Sequences were clustered into Amplicon Sequence Variants (ASV) using QIIME, and metagenomic content was inferred using PICRUSt. Our results showed a significant difference in alpha-diversity metrics: observed richness and Shannon indexes (Kruskal-Wallis test, H = 8.42, p &amp;lt;0.01 and H = 6.85, p &amp;lt;0.03, respectively) across levels of DNA damage (low, intermediate, and high). Post hoc tests with pairwise comparisons showed that, for both indexes, individuals with high levels of HPB-releasing DNA adducts had significantly lower alpha diversity than those with intermediate levels (p &amp;lt;0.05). However, there were no differences in beta diversity as measured by Bray-Curtis (R2 = 1.15, p = 0.2) and Jaccard (R2 = 1.1, p = 0.1) indices across individuals with different levels of HPB-releasing DNA adducts. Multivariable association tests revealed that high levels of the DNA adducts were positively associated with Enterobacteriaceae, while intermediate levels were associated with Porphyromonas endodontalis, Prevotella spp, Neisseria spp, Actinomyces spp, and Fusobacterium. In addition, predicted functional profiling showed that intermediate levels of HPB-releasing DNA adducts were positively associated with amino acid, carbohydrate, and hem biosynthesis, along with reductive tricarboxylic acid cycle and formaldehyde degradation pathways. Comparisons between AA and WH persons who smoke showed that AA had significantly higher alpha diversity as assessed by observed bacterial richness and The Shannon index (Wilcoxon rank-sum tests, q-value=0.03 and 0.004, respectively). Differences between AA and WH were also found for beta diversity (Bray-Curtis: R2=2.4, p=0.01, Jaccard: R2=1.9, p=0.01, weighted Unifrac R2=0.02 p=0.007). The abundance of taxa associated with intermediate levels of DNA damage (Prevotella spp, Neisseria spp, Actinomyces spp, Fusobacterium) was also higher in AA persons who smoke. Together, our findings suggest that certain compositional and functional characteristics of the oral microbiome may serve as indicators of macromolecular responses to harmful chemical exposures from tobacco. The potential mechanistic contribution of the oral microbiome to such responses and its potential role in the observed racial/ethnic differences in cancer risk due to smoking should be further investigated. Citation Format: Aleksandra Alcheva. Relationship between the oral microbiome and tobacco-induced DNA damage in African American and White persons who smoke [abstract]. In: Proceedings of the 15th AACR Conference on the Science of Cancer Health Disparities in Racial/Ethnic Minorities and the Medically Underserved; 2022 Sep 16-19; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2022;31(1 Suppl):Abstract nr C030.

Cirq® robotic assistance for thoracolumbar pedicle screw placement – feasibility, accuracy, and safety

IntroductionNew technologies providing higher degree of precision, less risk for damage and less harmful exposure to radiation are necessary for correct transpedicular screw trajectory, but their efficacy should be evaluated. Research QuestionEvaluate the feasibility, accuracy and safety of Brainlab Cirq® navigated robotic arm assistance for pedicle screw placement in comparison to fluoroscopic guidance. Material and MethodsGroup I “Cirq® robotic-assisted group” – 97 screws in 21 prospectively analyzed patients. Group II “Fluoroscopy-guided group” – 98 screws in 16 consecutive patients analyzed retrospectively. Comparative evaluations included screw accuracy on Gertzbein-Robbins’s scale and fluoroscopy time. Time per screw and subjective mental workload (MWL) measured with the raw NASA task load index tool were assessed for Group I. Results195 screws were evaluated. Group I: 93 screws grade A (95.88%); 4 grade B (4.12%). In Group II, 87 screws grade A (88.78%); 9 grade B (9.18%); 1 grade C (1.02%); 1 grade D (1.02%). While the screws placed using the Cirq® system were more accurate overall, there was no statistical significance between the two groups, p=0.3714. There was no significant difference in operation length or radiation exposure between the two groups, however with the Cirq® system the radiation exposure for the surgeon was limited. Reduction in time per screw (p<0.0001) and in the MWL (p=0.0024) correlated with the surgeon’s experience with Cirq®. Discussion and ConclusionThe initial experience suggests that navigated, passive robotic arm assistance is feasible, at least as accurate as fluoroscopic guidance, and safe for pedicle screw placement.

A MODERN VIEW ON THE PROBLEM OF DENTAL CARIES IN EARLY CHILDHOOD

Because of the rapid development of dental science and modern technologies, World Health Organization (WHO) included dental caries as one of the six modern diseases, prevention of which is the main aspect of nowadays. Initial caries is one of the few diseases that can accompany a person throughout their life, starting from early childhood. Early childhood caries is an international health problem in both developing and industrial countries. The most important aspect is the high prevalence of dental caries in children that makes a necessity to develop and implement, effective modern methods of prevention of this pathology, which would have a positive effect on the dental health of the child, and would ensure a low cost compared to treatment. Given the availability of a number of endogenous and exogenous methods of caries prevention, it remains relevant to improve, further develop and study complex individual treatment and prevention schemes to ensure a high reduction of initial caries. The combination of exogenous and endogenous prophylactic methods would increase the resistance of the oral cavity tissues and whole body to harmful exposure. The prevention of caries in children of young ages is main task of dental caries prevention, especially in children of the risk group, who are exposed by many risk factors that complicates the carious process. This topic is not only about the health of the oral cavity, but also about the health of the child’s entire body. Therefore, it is necessary to develop complexes of individual preventive measures by taking into account general and local risk factors for the occurrence of caries. Key words: caries, prevalence of caries, intensity of caries, measures and means of caries prevention.

Smoking cessation in pregnant women using financial incentives: a feasibility study

BackgroundThe high prevalence of smoking pregnant women in Dutch areas with lower socioeconomic status and the consecutively harmful exposure to tobacco to both mother and child, depicted a high need for a novel intervention. According to other studies, the utilisation of financial incentives appeared to be a promising method for smoking cessation in pregnant women. Therefore, the aim of this study was to investigate the feasibility of implementing contingent financial incentives as smoking cessation support for pregnant women in the Netherlands.MethodsFeasibility study consisting of four developmental phases: (1) acceptability of Dutch population regarding financial-incentive-intervention by conducting an online questionnaire, (2) composing a pilot study utilising the financial-incentive-intervention in clinical practice, (3) execution of the composed pilot study and (4) evaluation of the executed pilot study utilising a mixed-methods approach.A financial-incentive-intervention, given in a contingent financial scheme (during five consequential appointments, respectively €25/€50/€100/€150/€250), if smoking abstinence was proven by the amount of cotinine in the urine of the pregnant women measured utilising a urine dipstick test.The public acceptability for the financial-incentive-intervention was assessed using 5-Likert scales. The number of pregnant women able to abstain from smoking during the pilot study and utilising the financial-incentive-intervention in clinical practice were used to assess the prosperity and practicality of the pilot study respectively. The pilot study was evaluated using a mixed-methods approach.ResultsIn total, 55.1% of the Dutch population sample (n = 328) found a financial incentive inappropriate for smoking cessation in pregnant women, while the healthcare professionals and pilot study participants thought the financial-incentive-intervention to be a helpful approach. Eleven vouchers were given during the pilot study, and one woman completed all test points and tested negative for cotinine at the end of the pilot study.ConclusionAlthough the financial-incentive-intervention appeared to be a promising approach for smoking cessation in pregnant women, the acceptability of the Dutch population and the number of pregnant women able to abstain smoking during this pilot study was low. Despite the limited study population, this study proved the concept of this financial-incentive-intervention to be feasible for implementation in the Netherlands.Trial registrationNot applicable since this is a feasibility study prior to a trial.

WRF‐CHEM Simulations of Unhealthy PM10 Concentrations During Four Dust Events in Senegal

AbstractWinter season Saharan dust aerosols are transported into West Africa and pose as a natural hazard with individual dust events significantly reducing air quality. We simulate four multi‐day dust events using the Weather, Research and Forecasting Chemistry (WRF‐CHEM) in Senegal during December 2016, December 2017, February 2019, and March 2019. We use Geospatial Informational System mapping to estimate PM10 concentrations for the 14 administrative districts within Senegal. Saharan dust events are evaluated using surface PM10 concentrations at Dakar, Senegal, Moderate Resolution Imaging Spectrometer Aerosol Optical Depth, Aerosol Robotic Network, and the WRF‐CHEM model to evaluate dust concentrations across Senegal. We show that a north to south pressure gradient associated with the southward movement of the Azores high into North Africa are responsible for dust generation and transport into Senegal during 2016 and 2017. Conversely, Saharan depressions moving across the Sahara Desert are responsible for the two high‐impact dust events in February and March of 2019. Based on our analysis, the most severe of the four dust events impacting Senegal occurred in December 2017, with hazardous PM10 concentrations simulated for 7 days affecting an estimated 86% of Senegal's population. Furthermore, the February 2019 dust event occurred during the presidential elections, potentially exposing many voters to poor air quality. A network of surface dust observations and dust forecasts are critical for protecting the Sahelian public from dangerous dust events. Together, they allow for preventative measures to minimize harmful PM10 concentration exposure, especially for children under 5, the elderly, and those with existing respiratory and cardiovascular diseases.

Neonatal exposure to phthalate and alternative plasticizers via parenteral nutrition

Di-(2-ethylhexyl) phthalate (DEHP), a plasticizer used to soften plastic medical devices (PMDs), was restricted in PMDs due to adverse health effects, being gradually replaced by alternative plasticizers (APs). Parenteral nutrition (PN), essential in the care for premature neonates in the neonatal intensive care unit, is stored in plastic storage bags and administered intravenously through plastic infusion circuits. We investigated to which extent PN contributes to current phthalate and AP exposure in premature neonates. First, we showed that DEHP and several APs are present in relevant amounts in PMDs used for neonatal PN administration. Secondly, ex vivo experiments mimicking clinical PN administration showed that lipid emulsions contained significant concentrations of DEHP and several APs (ATBC, TOTM, DEHT & DEHA), while hardly any plasticizers were detected in non-lipid solutions. ATBC leached from infusion circuits, while lipid emulsions were the major source for DEHP, TOTM, DEHT, and DEHA. PN administration resulted in estimated daily exposures of 13.9 µg/kg/d DEHP and 95.7 µg/kg/d ATBC in premature neonates, below their respective reference doses. Our data indicate that premature neonates requiring PN are still exposed to DEHP, as well as to a range of APs, making it a target for reduction of harmful plasticizer exposure.

The association of diastolic arterial pressure and heart rate with mortality in septic shock: a retrospective cohort study

The effects of diastolic arterial pressure (DAP) and heart rate (HR) on the prognosis of patients with septic shock are unclear, and whether these effects persist over time is unknown. We aimed to investigate the relationship between exposure to different intensities of DAP and HR over time and mortality at 28days in patients with septic shock. In this cohort study, we obtained data from the Medical Information Mart for Intensive Care IV, which includes the data of adult patients (≥ 18years) with septic shock who underwent invasive blood pressure monitoring. We excluded patients who received extracorporeal membrane oxygenation (ECMO) or glucocorticoids within 48h of ICU admission. The primary outcome was mortality at 28days. Piece-wise exponential additive mixed models were used to estimate the strength of the associations over time. In total, 4959 patients were finally included. The median length of stay in the ICU was 3.2days (IQR: 1.5-7.1days), and the mortality in the ICU was 12.9%, with a total mortality at 28days of 15.9%. After adjustment for baseline and time-dependent confounders, both daily time-weighted average (TWA) DAP and HR were associated with increased mortality at 28days and strong association, mainly in the early to mid-stages of the disease. The results showed that mortality in patients with septic shock was lowest at a DAP of 50-70mm Hg and an HR of 60-90 beats per minute (bpm). Throughout, a significant increase in the risk of death was found with daily exposure to TWA-DAP ≤ 40mmHg (hazard ratio 0.99, 95% confidence interval (CI) 0.94-1.03) or TWA-HR ≥ 100bpm (hazard ratio 1.16, 95% CI 1.1-1.21). Cumulative and interactive effects of harmful exposure (TWA-DAP ≤ 40mmHg and TWA-HR ≥ 100bpm) were also observed. The optimal ranges for DAP and HR in patients with septic shock are 50-70mmHg and 60-90bpm, respectively. The cumulative and interactive effects of exposure to low DAP (≤ 40mmHg) and tachycardia (≥ 100bpm) were associated with an increased risk of death.

Machine Learning-Based Classification of Mushrooms Using a Smartphone Application

Worldwide, a large number of cases of harmful mushroom exposure and consumption result in hallucinations, sickness, and death. One contributing factor is that certain poisonous mushrooms closely resemble their edible counterparts, making it difficult for general public collectors to distinguish one from the other. We propose a method to classify mushroom types from field-collection images using a smartphone application based on a convolutional neural network. The application helps people without proper mycology background or training to distinguish poisonous mushrooms from edible ones with which they may be confused. We showed three case studies to classify two-, three-, and five-class models by optimizing their training steps by cross-validation. An android app was developed by transferring the server-based trained model and allowing users to obtain probability scores for the correct genus classification. Our experiments showed that this method could provide sensitivity and specificity of two-, three-, and five-class mushroom models ranging from 89% to 100% using an image from the field with diverse backgrounds and objects.

Thyroid dose reduction shield with the generation of less artifacts used for fast chest CT examination

Fast chest CT scans with high-pitch factors are effective to reduce motion artifacts, but the over-ranging effect may increase harmful radiation exposure to organs which are located near the outside of the imaging area. This becomes a particular problem during chest CT imaging when managing the radiation dose to the radio-sensitive thyroid, which is located around the upper end of the imaging area. The use of an X-ray shielding material can reduce the exposure dose to the thyroid. However, when the shielding is performed using metal foil, metal artifacts definitely appear, and they interfere with the CT image. To solve this problem, we developed a novel less-artifact thyroid shield in which fine bismuth oxide particles are embedded in low-density polyurethane (PU) foam. This study aims to present the usefulness of our X-ray shield through experimentation using a human body phantom. Three kinds of thyroid shields were used: a commercially-available lead foil as a reference, investigational clay products to evaluate the proper amount of the fine bismuth oxide particles, and bismuth PU shields which are proposed in this study. Furthermore, a bismuth PU shield with an added PU spacer was fabricated for the further suppression of the artifacts. Under clinical conditions, shielding ability and image quality were evaluated. Thyroid doses were measured using small-type OSL dosimeters, and the dose reduction rates were determined. In addition, the image qualities of the thyroid and lung regions were evaluated using a contrast-to-noise ratio (CNR) and an artifact index (AI). When the thyroid is outside the scanning region, thyroid exposure without the shield was caused by over-ranging X-rays and showed 11 mGy. When applying bismuth with an effective mass thickness of 0.12 g/cm2 to the bismuth PU shield, the thyroid exposure dose was reduced by half. In addition, we confirmed that if this shield enters the scanning region through accident, the AI would be less than 10. Also, when using our thyroid shield, the occurrence of metal artifacts was drastically suppressed. In conclusion, our thyroid shield can reduce the radiation exposure dose in half while maintaining acceptable image quality. This is a valuable tool in solving the issue of radiation exposure when performing fast chest CT scans. The shield has breathability and flexibility, and patients can apply the shield to their necks by themselves.

Principal Component Pursuit for Pattern Identification in Environmental Mixtures.

Environmental health researchers often aim to identify sources or behaviors that give rise to potentially harmful environmental exposures. We adapted principal component pursuit (PCP)-a robust and well-established technique for dimensionality reduction in computer vision and signal processing-to identify patterns in environmental mixtures. PCP decomposes the exposure mixture into a low-rank matrix containing consistent patterns of exposure across pollutants and a sparse matrix isolating unique or extreme exposure events. We adapted PCP to accommodate nonnegative data, missing data, and values below a given limit of detection (LOD). We simulated data to represent environmental mixtures of two sizes with increasing proportions and three noise structures. We applied PCP-LOD to evaluate its performance in comparison with principal component analysis (PCA). We next applied principal component pursuit with limit of detection (PCP-LOD) to an exposure mixture of 21 persistent organic pollutants (POPs) measured in 1,000 U.S. adults from the 2001-2002 National Health and Nutrition Examination Survey (NHANES). We applied singular value decomposition to the estimated low-rank matrix to characterize the patterns. PCP-LOD recovered the true number of patterns through cross-validation for all simulations; based on an a priori specified criterion, PCA recovered the true number of patterns in 32% of simulations. PCP-LOD achieved lower relative predictive error than PCA for all simulated data sets with up to 50% of the data . When 75% of values were , PCP-LOD outperformed PCA only when noise was low. In the POP mixture, PCP-LOD identified a rank-three underlying structure and separated 6% of values as extreme events. One pattern represented comprehensive exposure to all POPs. The other patterns grouped chemicals based on known structure and toxicity. PCP-LOD serves as a useful tool to express multidimensional exposures as consistent patterns that, if found to be related to adverse health, are amenable to targeted public health messaging. https://doi.org/10.1289/EHP10479.

Characterization of a Thermoacoustic-based Pulsed High Power Microwave Detector Chain.

Detection of microwave-induced thermoacoustic (TA) wave generation was evaluated as a potential technique for detection of high power microwave (HPM) directed energy exposure. Even when HPM is employed for counter-materiel effects, incidental but still potentially harmful personnel exposure is possible. Real-time detection of ongoing exposure with potentially unknown time and frequency domain characteristics is a critical first step in preventing acute health effects by alerting and then enabling the timely use of electromagnetic frequency energy shielding, such as structures and vehicles. Leveraging the TA effect as a field interaction mechanism, a lossy dielectric polymer subjected to pulsed HPM was tested using a planar sample geometry with thin film piezoelectric sensors used to capture the resulting TA output. The piezoelectric signal was analyzed in both the time and frequency domain to determine empirical relationships between incident microwave beam properties and signal components. This analysis was coupled with an empirically-based single term Cole-Cole model approximation fit for the complex permittivity. The results were used to identify appropriate signal conditioning and processing techniques needed to convert the TA response into a useful form for personnel exposure applications. These results also served as a comparison point for multi-physics finite element method computational modeling of the electromagnetic response of a simplified three-layer tissue model.

Light triggered programmable states of carbon dot liposomes accelerate chronic wound healing via photocatalytic cascade reaction

Bacterial infection in chronic wounds causes severe morbidity and mortality by prolonging the inflammation and proliferation phase during the healing process. Reported carbon nanomaterials can exert anti-microbial action; however, uncontrolled therapeutic response, cytotoxicity, and high dosage requirement have limited their potential. Toward the end, we have developed programmable carbon dot liposomes (CDsomes) from triolein through simple pyrolysis. CDsomes can achieve “on” and “off” states upon ultraviolet (UV; 385 nm) and green (532 nm) light irradiation, respectively. The “on” state CDsomes participate in a thermodynamically favorable photocatalytic reaction to produce hydrogen peroxide (H2O2), which acts as a substrate for the “off” state CDsomes (⋅CDsomes– or ⋅CDsomes+; metastable radical state) to generate hydroxyl radicals (⋅OH) via peroxidase-mimicking activity. The cascade reaction was utilized against bacteria, including multidrug-resistant bacteria. The practicality of CDsomes was demonstrated by treating the methicillin-resistant S. aureus infected wounds, CDsomes were pre-activated with UV light irradiation to avoid direct harmful exposure to tissues followed by in situ green light irradiation. This encouraged rapid healing by boosting the inflammatory immune responses owing to the intrinsic properties of self-preserved oleic acid. Light-triggered CDsomes with substantial biocompatibility holds great potential as an intelligent anti-microbial modality, particularly for chronic wound healing.

Modeling the transplacental transfer of small molecules using machine learning: a case study on per- and polyfluorinated substances (PFAS).

Despite their large numbers and widespread use, very little is known about the extent to which per- and polyfluoroalkyl substances (PFAS) can cross the placenta and expose the developing fetus. The aim of our study is to develop a computational approach that can be used to evaluate the of extend to which small molecules, and in particular PFAS, can cross to cross the placenta and partition to cord blood. We collected experimental values of the concentration ratio between cord and maternal blood (RCM) for 260 chemical compounds and calculated their physicochemical descriptors using the cheminformatics package Mordred. Weused the compiled database to, train and test an artificial neural network (ANN). And then applied the best performing model to predict RCM for a large dataset of PFAS chemicals (n = 7982). We, finally, examined the calculatedphysicochemical descriptors of the chemicals to identify which properties correlated significantly with RCM. We determined that 7855 compounds were within the applicability domain and 127 compounds are outside the applicability domain of our model. Our predictions of RCM for PFAS suggested that 3623 compounds had a log RCM > 0 indicating preferable partitioning to cord blood. Some examples of these compounds were bisphenol AF, 2,2-bis(4-aminophenyl)hexafluoropropane, and nonafluoro-tert-butyl 3-methylbutyrate. These observations have important public health implications as many PFAS have been shown to interfere with fetal development.In addition, asthese compounds are highly persistent and many of them can readilycross the placenta,they are expected to remain in the population for a long time as they are being passed from parent to offspring. Understanding the behavior of chemicals in the human body during pregnancy is critical in preventing harmful exposures during critical periods of development. Many chemicals can cross the placenta and expose the fetus, however, the mechanism by which this transport occurs is not well understood. In our study, we developed a machine learning model that describes the transplacental transfer of chemicals as a function of their physicochemical properties. The model was then used to make predictions for a set of 7982 per-and polyfluorinated alkyl substances that are listed on EPA's CompTox Chemicals Dashboard.The model can be applied to make predictions for other chemical categories of interest, such as plasticizers and pesticides. Accurate predictions of RCMcan help scientists and regulators to prioritize chemicals that have the potential to cause harm by exposing the fetus.

Phloretin Improves Ultrafiltration and Reduces Glucose Absorption during Peritoneal Dialysis in Rats.

Harmful glucose exposure and absorption remain major limitations of peritoneal dialysis (PD). We previously showed that inhibition of sodium glucose cotransporter 2 did not affect glucose transport during PD in rats. However, more recently, we found that phlorizin, a dual blocker of sodium glucose cotransporters 1 and 2, reduces glucose diffusion in PD. Therefore, either inhibiting sodium glucose cotransporter 1 or blocking facilitative glucose channels by phlorizin metabolite phloretin would reduce glucose transport in PD. We tested a selective blocker of sodium glucose cotransporter 1, mizagliflozin, as well as phloretin, a nonselective blocker of facilitative glucose channels, in an anesthetized Sprague-Dawley rat model of PD. Intraperitoneal phloretin treatment reduced glucose absorption by >30% and resulted in a >50% higher ultrafiltration rate compared with control animals. Sodium removal and sodium clearances were similarly improved, whereas the amount of ultrafiltration per millimole of sodium removed did not differ. Mizagliflozin did not influence glucose transport or osmotic water transport. Taken together, our results and previous results indicate that blockers of facilitative glucose channels may be a promising target for reducing glucose absorption and improving ultrafiltration efficiency in PD.

Energy efficient and privacy protection window system for smart home using polymer-dispersed liquid crystals glass

&lt;span&gt;Hot climates smart home system is steadily advancing recently. The main concern is energy efficiency particularly in the Arabian Gulf region. Privacy is another prioritized concern culturally. This project presents a solution for both demanded priorities implementing a polymer-dispersed liquid crystals (PDLC) glass system. The proposed design was validated via a developed prototype that was measured experimentally. Its experimental results show about 39% improvement in energy saving compared to conventional systems without depriving the indoor-outdoor connections and the privacy of the smart home inhabitants. Furthermore, it also achieves several other additional goals, for instance, decreasing cost as well as wasted energy by automatically off the lighting and air conditioning systems whenever they are not in used. Moreover, it is also capable to significantly reduce the risk of harmful exposure to ultraviolet A/B (UVA/B) of solar radiations, which conventional curtains are not capable to protect.&lt;/span&gt;