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Supported lipid bilayers (SLBs) are commonly used to investigate interactions between cell membranes and their environment. These model platforms can be formed on electrode surfaces and analyzed using electrochemical methods for bioapplications. Carbon nanotube porins (CNTPs) integrated with SLBs have emerged as promising artificial ion channel platforms. In this study, we present the integration and ion transport characterization of CNTPs in in vivo environments. We combine experimental and simulation data obtained from electrochemical analysis to analyze the membrane resistance of the equivalent circuits. Our results show that carrying CNTPs on a gold electrode results in high conductance for monovalent cations (K+ and Na+) and low conductance for divalent cations (Ca2+).

Urinary concentrations of phenols, parabens, and triclocarban have been extensively used as biomarkers of exposure. However, because these compounds are quickly metabolized and excreted in urine, characterizing participants' long-term average exposure from a few spot samples is challenging. To examine the variability of urinary concentrations of these compounds during pregnancy, we quantified four phenols, four parabens, and triclocarban in 357 first morning voids (FMVs) and 203 pooled samples collected during the second and third trimesters of 173 pregnancies. We computed intraclass correlation coefficients (ICCs) by the sample type (FMV and pool) across two trimesters and by the number of composite samples in pools, ranging from 2 to 4, within the same trimester. Among the three compounds detected in more than 50% of the samples, the ICCs across two trimesters were higher in pools (0.29-0.68) than in FMVs (0.17-0.52) and the highest ICC within the same trimester was observed when pooling either two or three composites. Methyl paraben and propyl paraben primarily exposed via cosmetic use had approximately 2-3 times higher ICCs than bisphenol A primarily exposed via diet. Our findings support that within-subject pooling of biospecimens can increase the reproducibility of pregnant women's exposure to these compounds and thus could potentially minimize exposure misclassification.

Little is known about temporal trends of pregnant women's exposures to environmental phenols and parabens. We quantified four phenols [bisphenol A (BPA), bisphenol F, bisphenol S, and triclosan), four parabens [butyl paraben, ethyl paraben (ETPB), methyl paraben (MEPB), and propyl paraben (PRPB)], and triclocarban in 760 urine samples collected during 2007-2014 from 218 California pregnant women participating in a high-familial risk autism spectrum disorder cohort. We applied multiple regression to compute least square geometric means of urinary concentrations and computed average annual percent changes. We compared our urinary concentrations with those of other study populations to examine geographic variations in pregnant women's exposure to these target compounds. Urinary concentrations of BPA, MEPB, ETPB, and PRPB in this study population decreased over the study period [percent change per year (95% confidence interval): -5.7% (-8.2%, -3.2%); -13.0% (-18.1%, -7.7%); -5.5% (-11.0%, 0.3%); and -13.3% (-18.3%, -8.1%), respectively] and were consistently lower than those in pregnant women in other U.S. regions during the same study period. In recent years, certain phenols and parabens with known adverse health effects are being regulated or replaced with alternatives, which explains decreased body burdens observed in this study population. Either the national regulations or the advocacy campaigns in California may have influenced exposures or consumer product choices.

Background/objectivePolyurethane foam (PUF), a proven sampling medium for measuring air concentrations of organic compounds, is widely used in upholstered home furniture. We evaluated the potential utility of couch PUF as a passive sampler and as a reservoir for non-flame retardant semivolatile organic compounds (SVOCs).MethodsWe collected PUF samples from 13 California home couches, measured concentrations (CPUF) of 64 SVOCs at three different depths (i.e., top, top-middle, and middle from couch surfaces facing outward), and examined concentration changes with depth. To calculate the PUF-air partition coefficient (KPUF-air = CPUF/Cair = CPUF × Kdust-air/Cdust), we used the calculated dust-air partition coefficient (Kdust-air) with the octanol-air partition coefficient (Koa) and dust concentrations (Cdust) simultaneously collected and measured. We used KPUF-air to compute fugacity capacity of PUF and chemical mass distribution among various indoor compartments and PUF.ResultsAmong 29 detected compounds, 11 compounds were detected in more than 50% of the samples at all depths. Among the 11 compounds, concentrations of phenanthrene, 2-benzylideneoctanal, galaxolide, tonalide, and homosalate decreased with depth. Among the studied SVOCs, more than 20% of the total mass was distributed to couch PUF for phenol and compounds in skin-applied products (i.e., 2-benzylideoneoctanal, galaxolide, and homosalate).ConclusionsOur results showed that couch PUF can absorb many SVOCs and may be an important reservoir for some SVOCs. However, it may not be an effective passive sampling medium for those that have relatively high Koa values. Direct dermal contact with couch seats may be an important exposure route for non-users of skin-applied compounds.

The determinants of the temporal variability of indoor dust concentrations of semivolatile organic compounds (SVOCs) remain mostly unexplored. We examined temporal variability of dust concentrations and factors affecting dust concentrations for a wide range of SVOCs. We collected dust samples three times from 29 California homes during a period of 22 months and quantified concentrations of 47 SVOCs in 87 dust samples. We computed intraclass correlation coefficients (ICCs) using three samples collected within the same house. We calculated correlation coefficients (r) between two seasons with similar climate (spring and fall) and between two seasons with opposite climate (summer and winter). Among 26 compounds that were detected in more than 50% of the samples at all three visits, 20 compounds had ICCs above 0.50 and 6 compounds had ICCs below 0.50. For 19 out of 26 compounds, correlation coefficients between spring and fall (r = 0.48-0.98) were higher than those between summer and winter (r = 0.09-0.92), implying seasonal effects on dust concentrations. Our study showed that within-home temporal variability of dust concentrations was small (ICC > 0.50) for most SVOCs, but dust concentrations may vary over time for some SVOCs with seasonal variations in source rates, such as product use.

Background/objectiveHuman exposure to per- and polyfluoroalkyl substances (PFAS) has changed since the early 2000s, in part, because of the phase-out and replacement of some long-chain PFAS. Studies of PFAS exposure and its temporal changes have been limited to date mostly to adults and pregnant women. We examined temporal trends and determinants of PFAS serum concentrations among mothers with a young child who participated in the CHARGE (CHildhood Autism Risk from Genetics and Environment) case-control study.MethodsWe quantified nine PFAS in serum samples collected from 2009 to 2016 in 450 Northern California mothers when their child was 2-5 years old. With five compounds that were detected in more than 50% of the samples, we performed multiple regression to estimate least square geometric means (LSGMs) of PFAS concentrations with adjustment for sampling year and other characteristics that may affect maternal concentrations (e.g., breastfeeding duration). We also used time-related regression coefficients to calculate percent changes over the study period.ResultsLSGM concentrations of perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS), and perfluorohexane sulfonate (PFHxS) decreased over the study period [percent change (95% confidence interval): -10.7% (-12.7%, -8.7%); -10.8% (-12.9%, -8.5%); -8.0% (-10.5%, -5.5%), respectively]. On the other hand, perfluorononanoate (PFNA) and perfluorodecanoate (PFDA) showed mixed time trends. Among the selected covariates, longer breastfeeding duration was associated with decreased maternal serum concentrations of PFOA, PFOS, PFHxS, PFNA and PFDA.ConclusionsOur study demonstrated that body burden of some common long-chain PFAS among California mothers with a young child decreased over the study period and that breastfeeding appears to contribute to the elimination of PFAS in lactating mothers.

Background: The clinical implications of structural integrity have been a subject of long debate. The oversimplified binary categorization of structural integrity into either healing or retear, along with faulty preoperative baselines for comparison, may contribute to the controversy. Purpose: To determine how the quality of structural integrity in a repaired cuff tendon affects both clinical and structural outcomes by dividing the patients into groups based on integrity and using the immediate postoperative baseline (time zero). Study design: Cohort study; Level of evidence, 3. Methods: A total of 504 patients with a full-thickness rotator cuff tear who underwent arthroscopic rotator cuff repair and were followed up for at least a year with magnetic resonance imaging (MRI) were included. The quality of structural integrity was graded using the Sugaya classification. To evaluate clinical outcomes, pain, range of motion, strength, functional scores, and overall satisfaction and function were used for within- and between-group analyses at the last follow-up. For the assessment of structural outcomes, the Goutallier classification for fatty infiltration (FI) and the tangent sign, occupation ratio, and normalized cross-sectional area for muscle atrophy (MA) were used. The baselines for these structural measurements were both the preoperative and the time-zero MRI scans. Results: The mean clinical follow-up period was 31.8 ± 27.5 months, and the MRI follow-up period was 10.9 ± 5.3 months. There were 178 (35.3%), 228 (45.2%), 58 (11.5%), 14 (2.8%), and 26 (5.2%) shoulders with Sugaya grades 1, 2, 3, 4, and 5, respectively. Regardless of structural integrity, all clinical outcomes at a mean follow-up of 31.8 months after repair significantly improved compared with those before repair. Only in shoulders with Sugaya grade 1 did the FI of the supraspinatus muscle improve significantly from baseline. FI of the infraspinatus muscle did not change significantly in those with grades 1 and 2 but worsened in those with grades 3 and 5. MA measured using the occupation ratio improved significantly in shoulders with Sugaya grades 1 and 2 but declined in those with grade 5. Conclusion: This study established a correlation between improved structural integrity of the repaired cuff tendon and enhanced structural outcomes in rotator cuff muscles. Furthermore, the findings revealed that both FI and MA could be reversed in patients exhibiting high-quality structural integrity. However, these structural improvements were not mirrored in the clinical outcomes. [ABSTRACT FROM AUTHOR]

Recent advances in semiconductor based electronic devices can be attributed to the technological demands of ever increasing, application specific markets. These rapidly evolving markets for devices such as displays, wireless communication, photovoltaics, medical devices, etc. are demanding electronic devices that are increasingly thinner, smaller, lighter and flexible. High-quality, III-V epitaxial thin-films deposited on single-crystal substrates have yielded extremely high-performance, but are extremely expensive and rigid. Here we demonstrate heteroepitaxial deposition of GaAs thin-films on large-grained, single-crystal-like, biaxially-aligned, flexible, metallic substrates. We use molecular beam epitaxy (MBE) for the controlled growth of high quality GaAs layers on lattice matched Ge capped, flexible metal substrates. The structural, optical, interfacial and electrical characteristics and properties of the heteroepitaxial GaAs layers are analyzed and discussed. The results show that heteroepitaxial GaAs layers with good crystalline and optoelectronic properties can be realized for flexible, III-V based semiconductor devices. III-V materials integrated on large-grained, single-crystal-like, flexible, metallic substrates offer a potential route towards fabrication of large-area, high-performance electronic devices. [ABSTRACT FROM AUTHOR]

With the rapid advancement of modern technology, flexible and wearable electronics, particularly electromechanical sensors, have gained considerable attention for motion‐based applications in medical health monitoring and artificial intelligence. Correspondingly, extensive efforts have been dedicated to enhancing their performance and practicality. Electromechanical sensors based on functional composites and structures accurately detect and monitor the body, generating the corresponding output signals. However, there are several limitations in manufacturing composite sensors, such as the selection and combination of functional materials, geometrical structures, constructed conductive pathways, stability of output signals, and operational lifetime. Thus, this review summarizes notable trends in the electromechanical sensors using functional composites and structures. This also provides an overview of different types of electromechanical pressure and strain sensors, exploring their operational mechanisms regarding triboelectricity, piezoelectricity, piezocapacitance, and piezoresistivity. The unique characteristics of functional materials, including conductive polymers, nanostructured metals, and carbon nanomaterials and composites, are analyzed alongside various design concepts for highly flexible and stretchable sensors. Furthermore, potential applications concerning human motion and human–machine interfaces are also recommended. Additionally, several future outlooks are reviewed for insights into future prospects and strategies. Thus, this review can assist readers in understanding current electromechanical devices more accurately. [ABSTRACT FROM AUTHOR]

This article examines the incidence of healthcare utilization for allergic and respiratory infectious diseases in children with asthma before and during the COVID-19 pandemic. The study analyzed data from the Korean Childhood Asthma Study (KAS) cohort and the Health Insurance Review and Assessment Service (HIRA) from March 2016 to March 2021. The findings showed significant decreases in hospital visits for allergic and respiratory diseases during the pandemic, with sustained reductions observed for one year. The decline in healthcare utilization may be attributed to factors such as reduced exposure to triggers and apprehension about accessing healthcare services. Further research is needed to explore the long-term effects of the pandemic on healthcare utilization. [Extracted from the article]