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ZnO nanorod arrays (NRs) with a large number of sharp tips and uniform shapes were grown on the carbon cloth (CC) by a simple hydrothermal method. Titanium nitride (TiN) nanoparticles with various thicknesses were deposited on the ZnO NRs by magnetron sputtering to obtain ZnO/TiN core-shell arrays. Field emission (FE) performance of ZnO NRs show close dependence on TiN coating thickness. The turn-on field first decreases and then increases with increasing TiN coating thickness from 60 nm to 300 nm. The arrays with a design architecture can strike a balance between increased emission sites and limited field shielding effects. ZnO/TiN240 core-shell NRs have the lower turn-on electric field at 0.79 V/μm and the higher current densities at 9.39 mA/cm2. The field enhancement factor (β) of ZnO/TiN240 is about 3.2 times that of the bare ZnO NRs. On the other hand, the electrochemical properties were improved due to the formation of core-shell heterojunction on the ZnO/TiN interface and porous structure, which makes the ion and charge transport more convenient. Hence, this work not only revealed that the ZnO/TiN core-shell structure exhibited excellent improvement in both FE and supercapacitors applications, but also that growing arrays on CC was expected to achieve flexible display.

Gene rearrangement of the mitochondrial genome of insects, especially the rearrangement of protein-coding genes, has long been a hot topic for entomologists. Although mitochondrial gene rearrangement is common within Annulipalpia, protein-coding gene rearrangement is relatively rare. As the largest family in Annulipalpia, the available mitogenomes from Hydropsychidae Curtis, 1835 are scarce, and thus restrict our interpretation of the mitogenome characteristic. In this study, we obtained 19 novel mitogenomes of Hydropsychidae, of which the mitogenomes of the genus Arctopsyche are published for the first time. Coupled with published hydropsychid mitogenome, we analyzed the nucleotide composition evolutionary rates and gene rearrangements of the mitogenomes among subfamilies. As a result, we found two novel gene rearrangement patterns within Hydropsychidae, including rearrangement of protein-coding genes. Meanwhile, our results consider that the protein-coding gene arrangement of Potamyia can be interpreted by the tandem duplication/random loss (TDRL) model. In addition, the phylogenetic relationships within Hydropsychidae constructed by two strategies (Bayesian inference and maximum likelihood) strongly support the monophyly of Arctopscychinae, Diplectroninae, Hydropsychinae, and Macronematinae. Our study provides new insights into the mechanisms and patterns of mitogenome rearrangements in Hydropsychidae.

Background and Objectives Triptolide (TP) is known to impair testicular development and spermatogenesis in mammals, but the mechanism of the side effects still needs to be investigated. The aim of the research is to confirm whether TP can cause autophagy in TM3 Leydig cells and the potential molecular pathway in vitro. Methods TM3 Leydig cells are used to investigate the molecular pathway through Western blot, detection of apoptosis, transmission electron microscopy for autophagosomes and so on. Results The data show that TP treatment resulted in the decreasing of the viability of TM3 cells due to the increased apoptosis. Treated with TP, the formation of autophagosomes, the decrease in P62, and the increase in the conversion of LC3-I to LC3-II suggested the induction of autophagy. The induction of autophagy has accompanied the activation of the mTOR/P70S6K signal pathway. The viability of the TM3 cells was further inhibited when they were co-treated with autophagy inhibitor, chloroquine (CQ). Conclusion All these data suggest that autophagy plays a very important role in antagonizing TM3 cell apoptosis during the TP exposure.

Eight organic-inorganic hybrid salts [(HL1)(SbCl4)] (1) (L1 = N,N-dimethylbenzylamine), [(HL2)2(ZnCl4)] (2) (L2 = 4-chlorobenzylamine), [(HL2)(L2)(CuCl3)(H2O)2] (3), [(HL3)2(Sb2OCl6)] (4) (L3 = qui...

In the present work, we report a high activity Ti3C2 MXene nanosheet/TiO2 (Ti3C2/TiO2) composite photocatalyst synthesized by a solvent-thermal method using tetrabutyl titanate (Ti(OBu)4) as Ti source and HF as assistant. The Ti3C2/TiO2 composites were characterized by transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), UV–Vis spectroscopy (UV–vis), fluorescence spectrometer (PL) and N2 adsorption-desorption. The photocatalytic performance of the Ti3C2/TiO2 composites was explored for the degradation of rhodamine B (RhB) under visible light irradiation. The results showed that more highly-active (001) crystal surfaces of TiO2 were exposed in the Ti3C2/TiO2 composites assisted by HF. The composite consisted of TiO2 microspheres and multilayer Ti3C2 exhibited optimal photocatalytic performance with relatively large specific surface area, large photocurrent and much lower impedances as compared to commercial TiO2 (P25) and pure TiO2. The optimized sample exhibited a degradation rate of 93.7% in 60 min, which was 20.5-fold higher than that of P25. The addition of the Ti3C2 effectively increased the lifetimes of the Ti3C2/TiO2 composites and suppressed the recombination of the electron-hole pairs. The density functional theory (DFT) calculations also revealed that the photogenerated electrons in the composites flowed from TiO2 to Ti3C2. The Schottky barrier at the TiO2–Ti3C2 interfaces effectively inhibited the electronic reflow to TiO2. The as-developed new Ti3C2-based complex with high photocatalytic activity under visible light irradiation might have effective and feasible application in the treatment of dye-containing wastewater.

Chlorella vulgaris (C. vulgaris) and Scenedesmus obliquus (S. obliquus) were compared to remove toxicity under conditions of sludge extract cultivation for 30 days. The toxicity of sludge extract, the growth characteristics, photosynthetic pigment, superoxide dismutase (SOD) enzyme and catalase (CAT) enzyme activities of the two microalgae were studied by contrast. The results showed that small molecular organic matter (500 Da) was more easily utilized by microalgae. The toxicity in the toxic group of C. vulgaris and S. obliquus on the 30

ZnO thin film with different morphologies from seed, array to grass was grown by simple aqueous solution method under room temperature. The morphologies, structure, optical properties and photocatalytic properties of the samples were characterised by transmission electron microscope, scanning electron microscope, X-ray diffraction, fluorescence spectrometer, UV-Vis spectrophotometer and photocurrent response. The results showed that the ZnO arrays and grassy ZnO were both hexagonal wurtzite with uniform distribution and regular growth on the glass substrate. ZnO thin film with different morphologies affected the utilisation efficiency of the ultraviolet light. Multiple light reflections inside the grassy ZnO greatly increase the light efficiency. The methyl blue degradation rate of grassy ZnO photocatalyst was superior under the UV light compared to the other ZnO morphologies. Grassy ZnO showed favourable stability after five cycles. The comparison of the ZnO semiconductor in different dimensions is helpful for further research on other photocatalysts as well as their potential application.

The design of hollow porous microstructure and the selection of reasonable dielectric composition are effective ways to obtain microwave absorbing (MWA) materials with outstanding performance. In this paper, polypyrrole decorated ZnO hollow porous composites (ZnO@PPy HPC) with improved MWA performance were successfully prepared by an in situ polymerization method. The results showed that PPy was uniformly loaded on the surface of ZnO hollow porous microspheres (ZnO HPM) to build a hierarchically core–shell hollow structure. The addition and proportion regulation of PPy can effectively improve the dielectric properties, generate interfacial polarization effect and achieve good impedance matching, leading to enhanced MWA characteristics of composite materials. ZnO@PPy HPC exhibited promising broadband microwave absorption properties. The minimum reflection loss (RL min) reached −48.5 dB at 14.5 GHz with broad effective bandwidth (less than −10 dB) of 6.2 GHz when the matching thickness was 2.2 mm. This study provides guidance for the development on a new type of microwave absorbing materials composed of hollow porous structure and conductive polymer.

SO2, previously known as the product of industrial waste, has recently been proven to be a novel gasotransmitter in the cardiovascular system. It is endogenously produced from the metabolism pathway of sulfur-containing amino acids in mammalians. Endogenous SO2 acts as an important controller in the regulation of many biological processes including cardiovascular physiological and pathophysiological events. Recently, the studies on the regulatory effect of endogenous SO2 on cell apoptosis and its pathophysiological significance have attracted great attention. Endogenous SO2 can regulate the apoptosis of vascular smooth muscle cells, endothelial cells, cardiomyocytes, neuron, alveolar macrophages, polymorphonuclear neutrophils and retinal photoreceptor cells, which might be involved in the pathogenesis of hypertension, pulmonary hypertension, myocardial injury, brain injury, acute lung injury, and retinal disease. Therefore, in the present study, we described the current findings on how endogenous SO2 is generated and metabolized, and we summarized its regulatory effects on cell apoptosis, underlying mechanisms, and pathophysiological relevance.

In the steelmaking industry, the state of the blast furnace tuyere is an important basis for obtaining the internal information of the blast furnace. Traditional detections mainly rely on manual experience judgment, which is a time-consuming and tiring procedure for a human. In order to improve the efficiency of the detection, this paper is devoted to applying artificial intelligence methods to blast furnace anomaly detection. However, because of the low imaging degree of the abnormal state monitoring of the furnace mouth, the difference in the abnormal category is inconspicuous, and it is difficulty to extract the features with the existing intelligent models. To solve these problems, a novel and stable method is proposed in this paper to classify the image recognition of the abnormal state of the tuyere into one category; this is a new architecture that combines multiple technologies. For the fine-grained image classification task, an improved abnormal state recognition algorithm of the blast furnace tuyere based on the channel attention residual mechanism is proposed. In the model, the dataset is augmented by rotating it at random angles to balance the amount of data in each category; then, the residual module is used to integrate high- and low-order feature information and optimize the network; then, the multi-layer channel attention module is added based on the channel attention residual mechanism, and it obtains the optimal parameter combination of the model through k-fold cross-validation. Moreover, the number of channels was reduced by half after channel fusion, which could effectively reduce the model parameters and model complexity. It is shown in our experiments that the proposed method has an accuracy rate of 97.10% in identifying the abnormal state of the tuyere in our collection of blast furnace tuyere datasets. In order to test the performance of the proposed method, some existing models, such as SERNet, ResNeXt, and repVGG, are involved for comparison, and the proposed method has a better classification effect in comparison to them.

SO2, previously known as the product of industrial waste, has recently been proven to be a novel gasotransmitter in the cardiovascular system. It is endogenously produced from the metabolism pathway of sulfur-containing amino acids in mammalians. Endogenous SO2 acts as an important controller in the regulation of many biological processes including cardiovascular physiological and pathophysiological events. Recently, the studies on the regulatory effect of endogenous SO2 on cell apoptosis and its pathophysiological significance have attracted great attention. Endogenous SO2 can regulate the apoptosis of vascular smooth muscle cells, endothelial cells, cardiomyocytes, neuron, alveolar macrophages, polymorphonuclear neutrophils and retinal photoreceptor cells, which might be involved in the pathogenesis of hypertension, pulmonary hypertension, myocardial injury, brain injury, acute lung injury, and retinal disease. Therefore, in the present study, we described the current findings on how endogenous SO2 is generated and metabolized, and we summarized its regulatory effects on cell apoptosis, underlying mechanisms, and pathophysiological relevance.

Background: As a result of evidence suggesting phthalate toxicity, their use has decreased in recent years. However, new phthalates and non-phthalate replacements have emerged in their place, with unknown potential impacts on health. Methods: We measured 15 phthalate, two di(2-ethylhexyl)terephthalate (DEHTP), and two di(isononyl)cyclohexane-1,2-dicarboxylate (DINCH) urinary metabolites, collected up to three times during pregnancy from 994 women in Northern Puerto Rico (2011-2017). We used tests of linear trend to asses changes in concentrations over time and linear mixed models to identify predictors of exposure (sociodemographic characteristics, drinking water sources, diet, product use). Results: Several phthalate metabolites decreased over the study period indicating decreased exposure, while the geometric mean of DEHTP metabolites (molecular sum) increased 3-fold between 2014-2017. Intraclass correlations revealed low to moderate reproducibility of these biomarkers across pregnancy. Several metabolites were associated with maternal age, income, education, pre-pregnancy BMI, drinking public water, use of cleaning and personal care products and ice cream consumption. DINCH metabolite concentrations remained low throughout the study period. Conclusion: Although exposure to some phthalates may be decreasing, exposure to replacements, such as DEHTP, is increasing. Additional studies are needed to further characterize sources of phthalate replacement chemicals and potential exposure-related health effects among vulnerable populations.

International audience; Background: Within-subject biospecimens pooling can theoretically reduce bias in dose-response functions from biomarker-based studies when exposure assessment suffers from classical-type error. However, collecting many urine voids each day is cumbersome. We evaluated the empirical validity of a within-subject pooling approach and compared several options to avoid sampling each void.Methods: In 16 pregnant women who collected a spot of each urine void over several nonconsecutive weeks, we compared concentrations of 10 phenols in daily, weekly, and pregnancy within-subject pools. We pooled either three or all daily samples. In a simulation study using these data, we quantified bias in dose-response functions when using one to 20 urine samples per subject to assess methylparaben (a compound with moderate within-subject variability) and bisphenol A (high variability) exposures.Results: Correlations between exposure estimates from pools of all and of only three voids per day were above 0.80 for all time windows and compounds, except for benzophenone-3 and triclosan in the daily time window (correlations, 0.57-0.68). With one spot sample to assess pregnancy exposure, correlations were all below 0.74. Using only one biospecimen led to attenuation bias in the dose-response functions of 29% (methylparaben) and 69% (bisphenol A); four samples for methylparaben and 18 for bisphenol A decreased bias to 10%.Conclusions: For nonpersistent chemicals, collecting and pooling three samples per day instead of all daily samples efficiently estimates exposures over a week or more. Collecting around 20 biospecimens can strongly limit attenuation bias for nonpersistent chemicals such as bisphenol A.

OBJECTIVE Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are suspected endocrine disruptors widely detected across populations. We examine the extent to which PFASs are associated with diabetes incidence and microvascular disease. Secondarily, we tested whether a lifestyle intervention modifies associations and decreases concentrations. RESEARCH DESIGN AND METHODS We analyzed data from a prospective cohort of 957 participants from the Diabetes Prevention Program (DPP) trial and Diabetes Prevention Program Outcomes Study (DPPOS). At baseline, participants were randomized to an intensive lifestyle intervention of diet, physical activity, and behavior modification or a placebo medication. We quantified plasma concentrations of six PFASs at baseline and 2 years after randomization. Participants were monitored for ∼15 years, repeatedly tested for diabetes, and evaluated for microvascular disease at the end of the follow-up. RESULTS A doubling in baseline branched perfluorooctanoic acid concentration was associated with a 14% increase in diabetes risk for the placebo (hazard ratio [HR] 1.14, 95% CI 1.04, 1.25) but not in the lifestyle intervention group (HR 1.01, 95% CI 0.92, 1.11, Pinteraction = 0.11). Mean change in plasma baseline branched perfluorooctanoic acid concentration was greater for the placebo (0.96 ng/mL; 95% CI 0.71, 1.22) compared with the lifestyle intervention group (0.31 ng/mL; 95% CI 0.14, 0.48) 2 years after randomization. Each doubling in N-ethyl-perfluorooctane sulfonamido acetic acid was associated with 17% greater odds of prevalent microvascular disease (OR 1.17, 95% CI 1.05, 1.31), and a similar association was observed for perfluorodimethylhexane sulfonic acid (OR 1.18, 95% CI 1.04, 1.35), regardless of treatment. CONCLUSIONS Some plasma PFASs were associated with diabetes and microvascular disease. Our results suggest that exercise and diet may attenuate the diabetogenic association of PFASs.

A novel ZnO nanorod array/reduced graphene oxide (ZnO array/rGO) composite coating was synthesised via the combination of seed layers-growth and aqueous solution reaction for the formation of ZnO nanorod arrays, which was further combined with rGO using a simple water bath method. The results revealed that perpendicular arrays with hexagonal planes were successfully fabricated. The size and density of the arrays could be optimised by adjusting the reactant concentrations. The influence of the rGO fraction in the ZnO array/rGO composites on the photocatalytic degradation of the methylene blue under UV radiation was investigated. It was found that the photocatalytic performance could be significantly improved by adding rGO. The enhanced photocatalytic activities were attributed to the interactions between ZnO nanorod arrays and rGO nanosheets and subsequently effective separation of photo-generated electron-hole pairs via rGO as electron sinks. The ZnO array/rGO composites presented advantages including facile and green preparation, long photo-electron lifetime, easy particle agglomeration and recovery, and therefore is expected to be an ideal photocatalysts for the future utilisation.

The TiO 2 modified carbon nanotube composites (TiO 2 /CNT) and Ag deposited ternary multilayered composites (Ag/TiO 2 /CNT) were prepared by chemical deposition and sonochemical reaction, respectively. The composites were characterised by transmission electron microscopy, scanning electron microscopy, X-ray diffraction, Fourier-transform infrared spectroscopy, and ultraviolet-visible (UV-vis). The results showed that anatase TiO 2 layers were wrapped on the surfaces of the CNTs. The face-centred-cubic structure of Ag nanoparticles (NPs) was dispersedly formed on the surfaces of the Ag/TiO 2 /CNT composites. The expected formation and good dispersion of Ag was obtained by high-intensity ultrasound irradiation assistance. All the resulted TiO 2 /CNT and Ag/TiO 2 /CNT composites exhibited a higher photocatalytic performance than that of TiO 2 for the degradation of methylene blue. The novel nanocomposite photocatalysts were developed through structural changes and double effects of carbon materials and noble metals as electron acceptors. Inhibited recombination of electron-hole pairs allows effective electron transfer and active redox reaction on the surfaces of the composites. The novel composite combines the CNTs with excellent electronic nature and nobel metallic NPs with the special semiconductor-metal junction. It can provide new guidance for the application of carbon nanotube-based photocatalytic materials in photocatalysis field from UV-vis spectrum.

Background: How carcinogen exposure varies across users of different, particularly noncigarette, tobacco products remains poorly understood. Methods: We randomly selected 165 participants of the Golestan Cohort Study from northeastern Iran: 60 never users of any tobacco, 35 exclusive cigarette, 40 exclusive (78% daily) waterpipe, and 30 exclusive smokeless tobacco (nass) users. We measured concentrations of 39 biomarkers of exposure in 4 chemical classes in baseline urine samples: tobacco alkaloids, tobacco-specific nitrosamines (TSNA), polycyclic aromatic hydrocarbons (PAH), and volatile organic compounds (VOC). We also quantified the same biomarkers in a second urine sample, obtained 5 years later, among continuing cigarette smokers and never tobacco users. Results: Nass users had the highest concentrations of tobacco alkaloids. All tobacco users had elevated TSNA concentrations, which correlated with nicotine dose. In both cigarette and waterpipe smokers, PAH and VOC biomarkers were higher than never tobacco users and nass users, and highly correlated with nicotine dose. PAH biomarkers of phenanthrene and pyrene and two VOC metabolites (phenylmercapturic acid and phenylglyoxylic acid) were higher in waterpipe smokers than in all other groups. PAH biomarkers among Golestan never tobacco users were comparable to those in U.S. cigarette smokers. All biomarkers had moderate to good correlations over 5 years, particularly in continuing cigarette smokers. Conclusions: We observed two patterns of exposure biomarkers that differentiated the use of the combustible products (cigarettes and waterpipe) from the smokeless product. Environmental exposure from nontobacco sources appeared to contribute to the presence of high levels of PAH metabolites in the Golestan Cohort. Impact: Most of these biomarkers would be useful for exposure assessment in a longitudinal study.

Novel zinc oxide (ZnO) array/polyurethane (PU) nanocomposite coatings on the stainless steel substrates was fabricated via a simple process. ZnO arrays were prepared using zinc nitrate and hexamethylenetetramine by a seed growth method, followed by the spinning of PU. The morphologies, structure, wettability, mechanical performance and infrared radiation properties were characterized by transmission electron microscope, scanning electron microscope, X-ray diffraction, surface contact angle, nanoindentation and infrared radiation tests. The corrosion properties of the ZnO array/PU nanocomposite coating were evaluated by the electrochemical tests. The results showed that the ZnO arrays were hexagonal wurtzite and well dispersed in the composite coatings, resulting in slight increase in hydrophilicity. The mechanical properties of the coatings were improved with increased content of the ZnO arrays. The as-prepared ZnO array/PU nanocomposite coatings exhibited excellent corrosion resistance. The infrared radiation performance was observed to be slightly improved as well. It is believed that the unique organic/inorganic nanocomposite coating offers the effective strategy and potential applications for designing the functional coatings of good corrosion resistance and mechanical properties in various polymer systems.

Background: Because phthalates are quickly metabolized and excreted in urine, and human exposures tend to be episodic, phthalate metabolite concentrations measured in a maternal spot urine sample are only indicative of recent exposure. Objective: To examine temporal variability of pregnant women's phthalate exposure using multiple first morning voids (FMV) and pooled samples. Methods: We quantified 14 metabolites of eight phthalates in 577 urine samples collected from 188 pregnancies in the MARBLES (Markers of Autism Risk in Babies – Learning Early Signs) study. We calculated intraclass correlation coefficients (ICCs) using two samples of the same urine type (i.e., two FMVs or two pools) collected across the 2nd and 3rd trimesters. We also calculated ICCs and FMV/pool concentration ratios using two samples (i.e., two FMVs or one FMV and one pool) collected within the same trimester. Results: Overall, ICCs were higher in pooled samples (0.24–0.87) than in FMVs (0.08–0.69). Regardless of the sample type, ICCs tended to be higher for metabolites for which exposure sources are personal care products or indoor residential materials than those for which diet is an important exposure source. ICCs tended to increase and FMV/pool ratios tended to decrease with an increasing number of composite samples in the pools. Conclusions: Our study helped determine the number of samples needed to capture moderate to high reproducibility of individual's average exposure to phthalates and the average exposure can be differently characterized depending on the number of samples in the pools. Keywords: First morning void, Intraclass coefficient, Phthalate exposure, Pooled sample, Variability

In this study, zinc oxide (ZnO)/polypyrrole (PPy) composites with flower- and rod-like structures were successfully fabricated by in situ polymerization and the hydrothermal method and used as microwave absorption (MWA) materials. The surface morphologies, crystal structures, and electromagnetic features of the as-prepared samples were measured by field-emission scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), and vector network analyzer (VNA). The results show that the conductive polymer PPy was successfully decorated on the surface of ZnO substrates. The MWA ability of flower- and rod-like ZnO/PPy composites is significantly enhanced after introduction of PPy. Rod-like ZnO/PPy composites exhibited superior MWA properties than those of flower-like ZnO/PPy. The former achieved a minimum reflection loss (RLmin) of −59.7 dB at 15.8 GHz with a thickness of 2.7 mm, and the effective absorption bandwidth (EAB, RL < −10 dB) covered 6.4 GHz. PPy addition and stacked structure of rod-like ZnO/PPy composites can effectively improve the dielectric properties, form multiple reflections of incident electromagnetic waves, and generate an interfacial polarization effect, resulting in improved MWA properties of composite materials.

STUDY QUESTION: Are in-utero or peripubertal exposures to phthalates, parabens and other phenols found in personal care products associated with timing of pubertal onset in boys and girls? SUMMARY ANSWER: We found some associations of altered pubertal timing in girls, but little evidence in boys. WHAT IS KNOWN ALREADY: Certain chemicals in personal care and consumer products, including low molecular weight phthalates, parabens and phenols, or their precursors, are associated with altered pubertal timing in animal studies. STUDY DESIGN, SIZE, DURATION: Data were from the Center for the Health Assessment of Mothers and Children of Salinas (CHAMACOS) longitudinal cohort study which followed 338 children in the Salinas Valley, California, from before birth to adolescence. PARTICIPANTS/MATERIALS, SETTING, METHODS: Pregnant women were enrolled in 1999–2000. Mothers were mostly Latina, living below the federal poverty threshold and without a high school diploma. We measured concentrations of three phthalate metabolites (monoethyl phthalate [MEP], mono-n-butyl phthalate and mono-isobutyl phthalate), methyl and propyl paraben and four other phenols (triclosan, benzophenone-3 and 2,4- and 2,5-dichlorophenol) in urine collected from mothers during pregnancy and from children at age 9. Pubertal timing was assessed among 179 girls and 159 boys every 9 months between ages 9 and 13 using clinical Tanner staging. Accelerated failure time models were used to obtain mean shifts of pubertal timing associated with concentrations of prenatal and peripubertal biomarkers. MAIN RESULTS AND THE ROLE OF CHANCE: In girls, we observed earlier onset of pubic hair development with prenatal urinary MEP concentrations and earlier menarche with prenatal triclosan and 2,4-dichlorophenol concentrations. Regarding peripubertal biomarkers, we observed: earlier breast development, pubic hair development and menarche with methyl paraben; earlier menarche with propyl paraben; and later pubic hair development with 2,5-dichlorophenol. In boys, we observed no associations with prenatal urinary biomarker concentrations and only one association with peripubertal concentrations: earlier genital development with propyl paraben. LIMITATIONS, REASONS FOR CAUTION: These chemicals are quickly metabolized and one to two urinary measurements per developmental point may not accurately reflect usual exposure. Associations of peripubertal measurements with parabens may reflect reverse causality: children going through puberty early may be more likely to use personal care products. The study population was limited to Latino children of low socioeconomic status living in a farmworker community and may not be widely generalizable. WIDER IMPLICATIONS OF THE FINDINGS: This study contributes to a growing literature that suggests that exposure to certain endocrine disrupting chemicals may impact timing of puberty in children. STUDY FUNDING/COMPETING INTEREST(S): This study was funded by the National Institute of Environmental Health Sciences and the US Environmental Protection Agency. The authors declare no conflicts of interest. TRIAL REGISTRATION NUMBER: N/A.

Background: During puberty, mammary tissue undergoes rapid development, which provides a window of heightened susceptibility of breast composition to the influence of endogenous and exogenous hormones. Exposure to endocrine-disrupting chemicals (EDC) may affect breast development and composition and the risk of developing breast cancer in adulthood. Methods: We evaluated the associations between breast density and urinary concentrations of phenols and phthalates collected at Tanner 1 (B1) and Tanner 4 (B4) in 200 Chilean girls. Total breast volume (BV), fibroglandular volume (FGV), and percent dense breast (%FGV) were evaluated at B4 using dual X-ray absorptiometry. Generalized estimating equations were used to analyze the association between concentrations of EDC biomarkers across puberty and breast density. Results: The geometric mean %FGV was 7% higher among girls in the highest relative to the lowest tertile of monocarboxyisooctyl phthalate [1.07; 95% confidence interval (CI), 1.01–1.14]. Monoethyl phthalate concentrations at B4 were positively associated with FGV (highest vs. lowest tertile: 1.22; 95% CI, 1.06–1.40). Bisphenol A displayed a U-shaped association with FGV; girls in the middle tertile had at least 10% lower FGV than girls in the lowest or highest tertiles. Monocarboxyisononyl phthalate showed a nonlinear association with BV. No other statistically significant associations were observed. Conclusions: Our results suggest that the developing breast tissue is susceptible to select EDCs during childhood and adolescence. Impact: This study may spur further investigations into environmental influences on breast development during puberty and how shifts in pubertal breast density track through the life course to modify breast cancer risk.

The sustainable development of a hydrogen economy requires hydrogen production from water electrolysis at a low cost, but the limited production of active and robust electrocatalysts using materials that are abundant on earth has restrained development. This article reports a heterostructure of a Mo

Background Toxicological studies highlight the potential neurotoxicity of perfluoroalkyl substances (PFAS) during fetal development. However, few epidemiological studies have examined the impact of childhood PFAS on neurodevelopment. Methods We employed data from 208 children in the Health Outcomes and Measures of the Environment Study, a birth cohort (Cincinnati, OH), to examine associations of six serum PFAS concentrations measured at 3 and 8 years with executive function assessed at 8 years using the validated parent-completed Behavior Rating Inventory of Executive Function survey. We used multiple informant models to identify susceptible windows of neurotoxicity to PFAS and executive function. We investigated trajectories of PFAS concentrations and whether sex modified these associations. Results Each ln-increase in perfluorononanoate (PFNA) at 8 years was associated with a 3.4-point increase (95% CI 0.4, 6.3) in metacognition score, indicating poorer function. Children with PFNA above the median at 8 years had poorer global executive functioning compared to children with concentrations consistently below median levels (β = 6.5, 95% CI 0.2, 12.9). Higher concurrent PFNA was associated with poorer behavior regulation among males, while associations among females were null (pPFNA×sex = 0.018). Children with higher concurrent perfluorooctanoate (PFOA) had increased odds of being at risk of having clinical impairments in metacognition (OR = 3.18, 95% CI 1.17, 8.60). There were no associations between perfluorooctane sulfonate and perfluorohexane sulfonate and executive function. Conclusions PFNA and PFOA at 8 years, but not 3 years, may be related to poorer executive function at 8 years. Results need to be confirmed in cohort studies with larger sample sizes.

In epidemiologic studies, classifying episodic exposures to chemicals with short half-lives, such as phthalates and phenols, is challenging. We assessed whether accounting for sources of variability unrelated to exposure pathways would improve the reproducibility of urine concentrations of select phthalate metabolites and phenols. In 2011, a subset of pregnant women (n = 19) enrolled in a prospective study provided first morning urine samples every 3-4 weeks between 16 and 36 weeks gestation. At the time of collection, we identified potential contributors to variations in urinary concentrations: weight gain, gestational age, time slept, time since awoke, time since last food/drink, and time since last void. We estimated intraclass correlation coefficients (ICCs) among repeat urine concentrations with and without adjustment for sources of variability using a random intercept linear mixed model. Concentrations of monoethyl phthalate, butyl, and propyl parabens were the most reproducible (ICCs: 0.68, 0.56, and 0.56, respectively). However, adjustment for potential sources of variability unrelated to exposure pathways did not materially improve reproducibility nor the ability of a single sample to predict exposure based on average biomarker concentrations across pregnancy. Future studies should carefully consider the exposure timeframe and the reliability of using biomarker concentrations from a single time point to represent exposures over pregnancy.

Design of inexpensive and highly efficient bifunctional electrocatalyst is paramount for overall water splitting. In this study, amorphous Ni–Fe–P alloy was successfully synthesized by one-step direct-current electrodeposition method. The performance of Ni–Fe–P alloy as a bifunctional electrocatalyst toward both hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) was evaluated in 30 wt% KOH solution. It was found that Ni–Fe–P alloy exhibits excellent HER and OER performances, which delivers a current density of 10 mA cm−2 at overpotential of ∼335 mV for HER and ∼309 mV for OER with Tafel slopes of 63.7 and 79.4 mV dec−1, respectively. Moreover, the electrolyzer only needs a cell voltage of ∼1.62 V to achieve 10 mA cm−2 for overall water splitting. The excellent electrocatalytic performance of Ni–Fe–P alloy is attributed to its electrochemically active constituents, amorphous structure, and the conductive Cu Foil.

Human exposure to consumer and personal care products chemicals such as phenols, including parabens and other antimicrobial agents, can be assessed through biomonitoring by quantifying urinary concentrations of the parent chemical or its metabolites, often after hydrolysis of phase II conjugates. Developing suitable analytical methods for the concurrent quantification of multiple exposure biomarkers is challenging because optimal conditions for the hydrolysis of such conjugates (e.g., O-glucuronides, N-glucuronides, sulfates) may differ depending on the biomarker. We evaluated the effectiveness of seven commercial hydrolytic enzymes to simultaneously hydrolyze N-glucuronides (using the antibacterial triclocarban as example compound) and other conjugates (using select phenols and parabens as examples) by using on-line solid phase extraction–high performance liquid chromatography-isotope dilution-tandem mass spectrometry. Incubation (30 min, 55 °C) with a genetically engineered β-glucuronidase (IMCS, ≥ 15 units/μL urine) hydrolyzed N-glucuronide triclocarban, but did not fully hydrolyze the conjugates of phenols and parabens. By contrast, incubation (4 h, 37 °C) with solid β-glucuronidase (Helix pomatia, Type H-1, ≥ 30 units/μL urine) or liquid β-glucuronidase/arylsulfatase (Helix pomatia, 30 units/μL urine [i.e., 30 μL/100 μL urine]) in the presence of 100 μL methanol for 100 μL urine completely hydrolyzed N-glucuronide triclocarban and the conjugates of several phenols and parabens, without cleaving the ester bond of the parabens to form p-hydroxybenzoic acid. These results highlight the relevance of method validation procedures that include optimizing the hydrolysis of phase II urinary conjugates (e.g., enzyme type and amount used, reaction time, temperature) to quantify accurately and concurrently multiple exposure biomarkers for biomonitoring purposes.

BACKGROUND: Phthalates and phenols are suspected endocrine disrupting chemicals that may adversely impact fetal outcomes following in utero exposure. Understanding predictors of exposure to phthalates and phenols during the prenatal period is important. METHODS: We measured urinary concentrations of 15 phthalate metabolites and 11 phenols in 446 pregnant women enrolled in the Healthy Start pre-birth cohort. Creatinine-adjusted geometric means (GM) for each urinary biomarker were compared across categories of potential sociodemographic and dietary predictors. To assess the independent relationship between each significant food group predictor and biomarker we used multivariable models, adjusted for sociodemographic predictors. RESULTS: The phthalate metabolites with the highest concentrations were monoethyl phthalate (GM: 41.1 μg/g creatinine) and monocarboxyisooctyl phthalate (GM: 20.5 μg/g creatinine). Benzophenone-3 (GM: 124.6 μg/g creatinine) and methyl paraben (GM: 119.9 μg/g creatinine) were the phenols with the highest concentrations. Concentrations of the metabolites of di-n-butyl phthalate and di(2-ethylhexyl) phthalate were significantly higher in younger, unmarried or unemployed mothers, those who were overweight or obese, those with lower educational attainment, or those of minority race/ethnicity (p-values

Background: Exposure to perfluoroalkyl substances (PFASs) may impact children's neurodevelopment. Objective: To examine the association of prenatal and early childhood serum PFAS concentrations with children's reading skills at ages 5 and 8years. Methods: We used data from 167 mother-child pairs recruited during pregnancy (2003–2006) in Cincinnati, OH, quantified prenatal serum PFAS concentrations at 16±3weeks of gestation and childhood sera at ages 3 and 8years. We assessed children's reading skills using Woodcock-Johnson Tests of Achievement III at age 5years and Wide Range Achievement Test-4 at age 8years. We used general linear regression to quantify the covariate-adjusted associations between natural log-transformed PFAS concentrations and reading skills, and used multiple informant model to identify the potential windows of susceptibility. Results: Median serum PFASs concentrations were PFOS>PFOA>PFHxS>PFNA in prenatal, 3-year, and 8-year children. The covariate-adjusted general linear regression identified positive associations between serum PFOA, PFOS and PFNA concentrations and children's reading scores at ages 5 and 8years, but no association between any PFHxS concentration and reading skills. The multiple informant model showed: a) Prenatal PFOA was positively associated with higher children's scores in Reading Composite (β: 4.0, 95% CI: 0.6, 7.4 per a natural log unit increase in exposure) and Sentence Comprehension (β: 4.2, 95% CI: 0.5, 8.0) at age 8years; b) 3-year PFOA was positively associated with higher children's scores in Brief Reading (β: 7.3, 95% CI: 0.9, 13.8), Letter Word Identification (β: 6.6, 95% CI: 1.1, 12.0), and Passage Comprehension (β: 5.9, 95% CI: 1.5, 10.2) at age 5years; c) 8-year PFOA was positively associated with higher children's Word Reading scores (β: 5.8, 95% CI: 0.8, 10.7) at age 8years. Prenatal PFOS and PFNA were positively associated with children's reading abilities at age 5years, but not at age 8years; 3-year PFOS and PFNA were positively associated with reading scores at age 5years. But PFHxS concentrations, at any exposure windows, were not associated with reading skills. Conclusion: Prenatal and childhood serum PFOA, PFOS and PFNA concentrations were positively associated with better children's reading skills at ages 5 and 8years, but no association was found between serum PFHxS and reading skills. Keywords: Prenatal, Childhood, Perfluoroalkyl substances (PFASs), Reading skills

Background: Growing evidence suggests that exposure to per- and polyfluoroalkyl substances (PFASs) may disrupt lipid homeostasis and liver function, but data in children are limited. Objective: We examined the association of prenatal and mid-childhood PFAS exposure with lipids and alanine aminotransferase (ALT) levels in children. Methods: We studied 682 mother-child pairs from a Boston-area pre-birth cohort. We quantified PFASs in maternal plasma collected in pregnancy (median 9.7weeks gestation, 1999–2002) and in child plasma collected in mid-childhood (median age 7.7years, 2007–2010). In mid-childhood we also measured fasting total (TC), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), and ALT. We then derived low-density lipoprotein cholesterol (LDL-C) from TC, HDL-C, and TG using the Friedewald formula. Results: Median (interquartile range, IQR) perfluorooctane sulfonate (PFOS), perfluorooctanoate (PFOA), and perfluorodecanoate (PFDeA) concentrations in child plasma were 6.2 (5.5), 4.3 (3.0), and 0.3 (0.3) ng/mL, respectively. Among girls, higher child PFOS, PFOA, and PFDeA concentrations were associated with detrimental changes in the lipid profile, including higher TC and/or LDL-C [e.g., β per IQR increment in PFOS=4.0mg/dL (95% CI: 0.3, 7.8) for TC and 2.6mg/dL (−0.5, 5.8) for LDL-C]. However, among both boys and girls, higher plasma concentrations of these child PFASs were also associated with higher HDL-C, which predicts better cardiovascular health, and slightly lower ALT, which may indicate better liver function. Prenatal PFAS concentrations were also modestly associated with improved childhood lipid and ALT levels. Conclusions: Our data suggest that prenatal and mid-childhood PFAS exposure may be associated with modest, but somewhat conflicting changes in the lipid profile and ALT levels in children. Keywords: Per- and polyfluoroalkyl substances, Lipids, Liver function, Pregnancy, Childhood

Objective To investigate the association between urinary triclosan concentrations and antral follicle count (AFC), a well-accepted marker of ovarian reserve, among women from a fertility center. Design Prospective cohort study. Setting Hospital fertility center. Patient(s) A total of 109 women. Intervention(s) Urinary triclosan concentrations quantified by online solid phase extraction-high performance liquid chromatography-isotope dilution tandem mass spectrometry. Main Outcome Measure(s) AFC through transvaginal ultrasonography on the third day of an unstimulated menstrual cycle or on the third day of a progesterone withdrawal bleed. Result(s) The geometric mean of the specific gravity–adjusted urinary triclosan concentrations for the 225 samples provided by the 109 women was 13.0 μg/L (95% confidence interval [CI], 8.9, 19.1). Women had median (with interquartile range) AFC of 13 (8, 18). The specific gravity–adjusted urinary triclosan concentrations were inversely associated with AFC (−4%; 95% CI, −7%, −1%). Women with triclosan concentrations above the median had lower AFC compared with those whose triclosan concentrations were equal to or below the median, with an adjusted difference of −3.2 (95% CI, −3.9, −1.6) among those with a body mass index 2 and −1.8 (95% CI, −3.2, −0.3) among those who were Conclusion(s) Specific gravity–adjusted urinary triclosan concentrations were inversely associated with AFC in women seeking care at a fertility center. This association was modified by age and body mass index, with the younger and leaner women showing larger decreases in AFC.

Tin oxide nanostructured arrays with different morphologies were grown on stainless-steel mesh substrates by a simple thermal evaporation process. It was found that the SnO 2 nanostructures could be easily changed from nanobelts to nanocones, nanoneedles, micro-rods, ultra-long nanowires, and slim nanorods by controlling the parameters of growth temperature and N 2 /O 2 flow. A model combining vapor-liquid-solid (VLS)-base growth and vapor-solid (VS)-tip growth was proposed to explain the growth of SnO 2 nanostructures with manifold morphologies. Field-emission (FE) studies revealed that the morphologies of these patterned SnO 2 nanostructures had considerable effects on the FE properties. Among these nanostructures, ultra-long nanowire arrays had the lowest turn-on field (~0.47 V/um) and the highest field enhancement factor (~8848). More importantly, the ultra-long nanowire emitters showed excellent FE stability with fluctuations within 2.7%. The enhanced FE properties may be attributed to synergic effects arising from the aligned structures of the ultra-long nanowire emitters, their smaller areal density and their highest aspect ratio (~12000).

Di-2-ethylhexyl terephthalate (DEHTP), a structural isomer of di-2-ethylhexyl phthalate (DEHP), is a plasticizer used in a variety of commercial applications, but data on Americans’ exposure to DEHTP do not exist. We investigated the exposure to DEHTP in a convenience group of U.S. adults by analyzing urine collected anonymously in 2000 (N = 44), 2009 (N = 61), 2011 (N = 81), 2013 (N = 92), and 2016 (N = 149) for two major DEHTP oxidative metabolites: mono-2-ethyl-5-carboxypentyl terephthalate (MECPTP) and mono-2-ethyl-5-hydroxyhexyl terephthalate (MEHHTP). For comparison, we also quantified the analogous DEHP metabolites mono-2-ethyl-5-hydroxyhexyl phthalate (MEHHP) and mono-2-ethyl-5-carboxypentyl phthalate (MECPP). We detected MECPTP, MEHHP, and MECPP in all samples collected in 2016 with geometric means of 13.1, 4.1, and 6.7 ng/mL, respectively; we detected MEHHTP in 91% of the samples (geometric mean = 3.1 ng/mL). Concentrations of MECPTP correlated well with those of MEHHTP (R 2 = 0.8, p 0.05) suggesting different sources of exposure to DEHP and DEHTP. We also evaluated the fraction of the metabolites eliminated in their free (i.e., unconjugated) form. The median percent of unconjugated species was lower for the DEHP metabolites (MECPP [45.5%], MEHHP [1.9%]) compared to the DEHTP metabolites (MECPTP [98.8%], MEHHTP [21.2%]). Contrary to the downward trend from 2000 to 2016 in urinary concentrations of MEHHP and MECPP, we observed an upward trend for MEHHTP and MECPTP. These preliminary data suggest that exposure to DEHTP may be on the rise. Nevertheless, general population exposure data using MEHHTP and MECPTP as exposure biomarkers would increase our understanding of exposure to DEHTP, one of the known DEHP alternatives.

Background General population human biomonitoring programs such as the National Health and Nutrition Examination Survey (NHANES) in the United States suggest that chemical exposures are common. Exposures during childhood may affect health later in life, but biomonitoring data in NHANES among pre-school aged children are limited. Methods A convenience group of 122 3–5 year old American boys and girls were recruited in 2013 for a pilot study to assess the feasibility of collecting urine from young children and analyzing it for select chemical exposure biomarkers for future NHANES. Children were primarily Hispanic (64.8%); the remainder was divided between non-Hispanic black, and non-Hispanic white and “other.” We measured 52 urinary biomarkers: 13 phthalates and one non-phthalate plasticizer, five phenols and four parabens, 10 polycyclic aromatic hydrocarbons (PAHs), and 19 pesticides. For each biomarker, we calculated descriptive statistics. We also calculated the number of biomarkers detected within each child, and performed principal components analysis (PCA). Results NHANES staff obtained permission to attempt collection of 60 mL urine from 3 to 5 year olds who participated in the 2013 NHANES health examination; 83% of children successfully provided the target volume. We detected 24 individual biomarkers of pesticides, phenols and parabens, phthalates/non-phthalate plasticizers, and PAHs in 95–100% of children. The median number of biomarkers detected was 37: nine pesticides, five phenols and parabens, 13 phthalates and non-phthalate plasticizers, and 10 PAHs. Biomarkers concentrations appear to be similar to national estimates among 6–11 year old children from previous NHANES. PCA suggested high within-class correlations among biomarkers. Conclusions These young children successfully adhered to the collection protocol and produced enough urine for the quantification of environmental biomarkers currently being measured in NHANES participants 6 years of age and older. Using the same analytical methods employed for the analysis of samples collected from older NHANES participants, in this sample of pre-school aged children we detected multiple chemicals including plasticizers, combustion products, personal-care product chemicals, and pesticides. Starting with NHANES 2015–2016, the NHANES biomonitoring program will include urinary biomarkers for 3–5 year old children to provide exposure data to select chemicals at the national level among this age group.

Background: Few studies have examined whether prenatal exposure to perfluoroalkyl substances (PFASs) is associated with childhood adiposity. Objective: We examined associations of prenatal exposure to PFASs with adiposity in early and mid-childhood. Methods: We measured plasma PFAS concentrations in 1,645 pregnant women (median, 9.6 weeks gestation) enrolled in Project Viva, a prospective pre-birth cohort study in Massachusetts (USA), between 1999 and 2002. We assessed overall and central adiposity in 1,006 children in early childhood (median, 3.2 years) and 876 in mid-childhood (median, 7.7 years) using anthropometric and dual X-ray absorptiometry (DXA) measurements. We fitted multivariable linear regression models to estimate exposure-outcome associations and evaluated effect modification by child sex. Results: Median (25–75th percentiles) prenatal plasma perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS), perfluorohexane sulfonate (PFHxS), and perfluorononanoate (PFNA) concentrations in children assessed in early childhood were 5.6 (4.1–7.7), 24.8 (18.4–33.9), 2.4 (1.6–3.8), and 0.6 (0.5–0.9) ng/mL, respectively. Among girls, each interquartile range increment of prenatal PFOA concentrations was associated with 0.21 kg/m 2 (95% CI: –0.05, 0.48) higher body mass index, 0.76 mm (95% CI: –0.17, 1.70) higher sum of subscapular and triceps skinfold thickness, and 0.17 kg/m 2 (95% CI: –0.02, 0.36) higher DXA total fat mass index in mid-childhood. Similar associations were observed for PFOS, PFHxS, and PFNA. We observed null associations for boys and early-childhood adiposity measures. Conclusions: In this cohort, prenatal exposure to PFASs was associated with small increases in adiposity measurements in mid-childhood, but only among girls. Antecedentes: pocos estudios han examinado si la exposición prenatal a sustancias perfluoroalquilo (PFAS) está asociada con la adiposidad infantil. Objetivo: Examinamos las asociaciones de la exposición prenatal a los PFAS con la adiposidad en la niñez temprana y media. Métodos: medimos las concentraciones plasmáticas de PFAS en 1.645 mujeres embarazadas (mediana, 9,6 semanas de gestación) inscritas en Project Viva, un estudio prospectivo de cohortes prenatal en Massachusetts (EE. UU.), Entre 1999 y 2002. Evaluamos la adiposidad general y central en 1.006 niños en la primera infancia (mediana, 3,2 años) y 876 en la infancia media (mediana, 7,7 años) mediante mediciones antropométricas y de absorciometría de rayos X duales (DXA). Ajustamos modelos de regresión lineal multivariable para estimar las asociaciones exposición-resultado y evaluamos la modificación del efecto por sexo del niño. Resultados: La mediana (percentiles 25-75) de perfluorooctanoato plasmático prenatal (PFOA), sulfonato de perfluorooctano (PFOS), sulfonato de perfluorohexano (PFHxS) y perfluorononanoato (PFNA) en niños evaluados en la primera infancia fue de 5,6 (4,1-7,7), 24,8 ( 18,4 a 33,9), 2,4 (1,6 a 3,8) y 0,6 (0,5 a 0,9) ng / ml, respectivamente. Entre las niñas, cada incremento del rango intercuartílico de las concentraciones prenatales de PFOA se asoció con 0,21 kg / m 2 (IC del 95%: –0,05, 0,48) mayor índice de masa corporal, 0,76 mm (IC del 95%: –0,17, 1,70) mayor suma de subescapular y espesor del pliegue cutáneo del tríceps, y 0,17 kg / m 2 (IC del 95%: –0,02, 0,36) índice de masa grasa total DXA más alto en la infancia media. Se observaron asociaciones similares para PFOS, PFHxS y PFNA. Observamos asociaciones nulas para los niños y las medidas de adiposidad en la primera infancia. Conclusiones: En esta cohorte, la exposición prenatal a los PFAS se asoció con pequeños aumentos en las mediciones de adiposidad en la infancia media, pero solo entre las niñas. Antecedentes: Poucos estudos examinaram se a exposição pré-natal a substâncias perfluoroalquil (PFASs) está associada à adiposidade infantil. Objetivo: Nós examinamos associações de exposição pré-natal a PFASs com adiposidade na primeira e na metade da infância. Métodos: Medimos as concentrações plasmáticas de PFAS em 1.645 mulheres grávidas (mediana, 9,6 semanas de gestação) inscritas no Projeto Viva, um estudo de coorte prospectivo pré-nascimento em Massachusetts (EUA), entre 1999 e 2002. Avaliamos a adiposidade geral e central em 1.006 crianças na primeira infância (mediana, 3,2 anos) e 876 na meia-infância (mediana, 7,7 anos) usando medidas antropométricas e absortometria de raio-X duplo (DXA). Ajustamos modelos de regressão linear multivariável para estimar as associações de exposição-desfecho e avaliamos a modificação do efeito por sexo da criança. Resultados: As concentrações de perfluorooctanoato plasmático pré-natal (PFOA), perfluorooctano sulfonato (PFOS), perfluorohexano sulfonato (PFHxS) e perfluorononanoato (PFNA) em crianças avaliadas na primeira infância foram 5,6 (4,1-7,7), 24,8 ( 18,4–33,9), 2,4 (1,6–3,8) e 0,6 (0,5–0,9) ng / mL, respectivamente. Entre as meninas, cada incremento do intervalo interquartil das concentrações pré-natais de PFOA foi associado a 0,21 kg / m 2 (IC 95%: -0,05, 0,48) índice de massa corporal mais alto, 0,76 mm (IC 95%: -0,17, 1,70) maior soma do subescapular e espessura da dobra cutânea tricipital, e 0,17 kg / m 2 (IC 95%: –0,02, 0,36) índice de massa gorda total DXA mais alto no meio da infância. Associações semelhantes foram observadas para PFOS, PFHxS e PFNA. Observamos associações nulas para meninos e medidas de adiposidade na primeira infância. Conclusões: Nesta coorte, a exposição pré-natal a PFASs foi associada a pequenos aumentos nas medidas de adiposidade no meio da infância, mas apenas entre as meninas. Boston University School of Public Health, United States Universidad Nacional, Costa Rica Harvard Medical School and Harvard Pilgrim Health Care Institute, United States Harvard T.H. Chan School of Public Health, United States National Center for Environmental Health, United States University of California, United States Instituto Regional de Estudios en Sustancias Tóxicas

Background: Perfluoroalkyl substances (PFASs) are synthetic chemicals that may persist in the environment and in humans. There is a possible association between early-life PFAS exposure and metabolic dysfunction in later life, but data are limited. Methods: We studied 665 mother–child pairs in Project Viva, a Boston, Massachusetts-area cohort recruited 1999–2002. We quantified concentrations of PFASs [perfluorooctanoate (PFOA), perfluorooctane sulfonate (PFOS), perfluorononanoate (PFNA), perfluorohexane sulfonate (PFHxS), and perfluorodecanoate (PFDeA)] in maternal plasma collected at the first prenatal visit (median, 9.6 weeks gestation) and in child plasma from the mid-childhood research visit (median, 7.7 years). We assessed leptin, adiponectin, and homeostatic model assessment of insulin resistance (HOMA-IR) in mid-childhood. We fit covariate-adjusted linear regression models and conducted stratified analyses by child sex. Results: Children with higher PFAS concentrations had lower HOMA-IR [e.g., –10.1% (95% CI: –17.3, –2.3) per interquartile range increment in PFOA]. This inverse association between child PFAS and HOMA-IR was more pronounced in females [e.g., PFOA: –15.6% (95% CI: –25.4, –4.6) vs. –6.1% (95% CI: –16.2, 5.2) for males]. Child PFAS plasma concentrations were not associated with leptin or adiponectin. Prenatal PFAS plasma concentrations were not associated with leptin, adiponectin, or HOMA-IR in offspring. Conclusions: We found no evidence for an adverse effect of early-life PFAS exposure on metabolic function in mid-childhood. In fact, children with higher PFAS concentrations had lower insulin resistance. Antecedentes: las sustancias perfluoroalquilo (PFAS) son sustancias químicas sintéticas que pueden persistir en el medio ambiente y en los seres humanos. Existe una posible asociación entre la exposición temprana al PFAS y la disfunción metabólica en la edad adulta, pero los datos son limitados. Métodos: Estudiamos 665 parejas de madre e hijo en el Proyecto Viva, una cohorte del área de Boston, Massachusetts, reclutada en 1999-2002. Se cuantificaron las concentraciones de PFAS [perfluorooctanoato (PFOA), sulfonato de perfluorooctano (PFOS), perfluorononanoato (PFNA), sulfonato de perfluorohexano (PFHxS) y perfluorodecanoato (PFDeA)] en el plasma materno recolectado en la primera visita prenatal (mediana de 9,6 semanas), y en el plasma infantil de la visita de investigación de la niñez media (mediana, 7,7 años). Evaluamos la leptina, la adiponectina y la evaluación del modelo homeostático de la resistencia a la insulina (HOMA-IR) en la infancia media. Ajustamos modelos de regresión lineal ajustados por covariables y realizamos análisis estratificados por sexo del niño. Resultados: Los niños con concentraciones más altas de PFAS tenían HOMA-IR más bajo [por ejemplo, –10,1% (IC del 95%: –17,3, –2,3) por incremento de rango intercuartílico en PFOA]. Esta asociación inversa entre PFAS infantil y HOMA-IR fue más pronunciada en las mujeres [p. Ej., PFOA: –15,6% (IC del 95%: –25,4, –4,6) frente a –6,1% (IC del 95%: –16,2, 5,2) para machos]. Las concentraciones plasmáticas de PFAS en niños no se asociaron con leptina o adiponectina. Las concentraciones plasmáticas prenatales de PFAS no se asociaron con leptina, adiponectina o HOMA-IR en la descendencia. Conclusiones: No encontramos evidencia de un efecto adverso de la exposición temprana al PFAS sobre la función metabólica en la niñez media. De hecho, los niños con concentraciones más altas de PFAS tenían menor resistencia a la insulina. Antecedentes: As substâncias perfluoroalquílicas (PFASs) são produtos químicos sintéticos que podem persistir no meio ambiente e nos seres humanos. Há uma possível associação entre a exposição precoce ao PFAS e disfunção metabólica na vida adulta, mas os dados são limitados. Métodos: Estudamos 665 pares de mãe e filho no Projeto Viva, uma coorte da área de Boston, Massachusetts, recrutada em 1999–2002. Quantificamos as concentrações de PFASs [perfluorooctanoato (PFOA), perfluorooctano sulfonato (PFOS), perfluorononanoato (PFNA), sulfonato de perfluorohexano (PFHxS) e perfluorodecanoato (PFDeA)] no plasma materno coletado na primeira visita pré-natal (mediana). e no plasma infantil da visita de pesquisa do meio da infância (mediana, 7,7 anos). Avaliamos a leptina, a adiponectina e a avaliação do modelo homeostático de resistência à insulina (HOMA-IR) no meio da infância. Ajustamos modelos de regressão linear ajustados por covariável e conduzimos análises estratificadas por sexo da criança. Resultados: Crianças com concentrações mais altas de PFAS tiveram menor HOMA-IR [por exemplo, –10,1% (IC 95%: –17,3, –2,3) por incremento do intervalo interquartil no PFOA]. Esta associação inversa entre crianças PFAS e HOMA-IR foi mais pronunciada em mulheres [por exemplo, PFOA: –15,6% (IC 95%: –25,4, –4,6) vs. –6,1% (IC 95%: –16,2, 5,2) para machos]. As concentrações plasmáticas de crianças PFAS não foram associadas à leptina ou adiponectina. As concentrações plasmáticas de PFAS pré-natal não foram associadas à leptina, adiponectina ou HOMA-IR na prole. Conclusões: Não encontramos evidências de um efeito adverso da exposição precoce ao PFAS sobre a função metabólica na metade da infância. Na verdade, crianças com concentrações mais altas de PFAS apresentaram menor resistência à insulina. Boston Children’s Hospital, United States Harvard Medical School, United States Harvard Pilgrim Health Care Institute, United States Boston University School of Public Health, United States Universidad Nacional, Costa Rica National Center for Environmental Health, United States Harvard School of Public Health, United States University of California, United States Instituto Regional de Estudios en Sustancias Tóxicas

To study potential environmental influences on puberty in girls, we investigated urinary biomarkers in relation to age at menarche. Phenols and phthalates were measured at baseline (6–8 years of age). Menarche was ascertained over 11 years for 1051 girls with menarche and biomarkers. Hazards ratios were estimated from Cox models adjusted for race/ethnicity and caregiver education (aHR, 95% confidence intervals [CI] for 5th vs 1st quintile urinary biomarker concentrations). 2,5-Dichlorophenol was associated with earlier menarche (aHR 1.34 [1.06–1.71]); enterolactone was associated with later menarche (aHR 0.82 [0.66–1.03]), as was mono-3-carboxypropyl phthalate (MCPP) (aHR 0.73 [0.59–0.91]); the three p-trends were

Background Bisphenol A (BPA) toxicity and exposure risk to humans has been the subject of considerable scientific debate; however, published occupational exposure data for BPA are limited. Methods In 2013-2014, 77 workers at six US companies making BPA, BPA-based resins, or BPA-filled wax provided seven urine samples over two consecutive work days (151 worker-days, 525 samples). Participant information included industry, job, tasks, personal protective equipment used, hygiene behaviors, and canned food/beverage consumption. Total (free plus conjugated) BPA, quantified in urine by mass spectrometry, was detected in all samples. Results The geometric mean (GM) creatinine-adjusted total BPA (total BPACR) concentration was 88.0 µg g-1 (range 0.78-18900 µg g-1), ~70 times higher than in US adults in 2013-2014 (1.27 µg g-1). GM total BPACR increased during Day 1 (26.6-127 µg g-1), decreased by pre-shift Day 2 (84.4 µg g-1) then increased during Day 2 to 178 µg g-1. By industry, baseline and post-baseline total BPACR was highest in BPA-filled wax manufacturing/reclaim (GM = 111 µg g-1) and lowest in phenolic resin manufacturing (GM = 6.56 µg g-1). By job, total BPACR was highest at baseline in maintenance workers (GM = 157 µg g-1) and post-baseline in those working with molten BPA-filled wax (GM = 441 µg g-1). Workers in the job of flaking a BPA-based resin had the lowest concentrations at baseline (GM = 4.81 µg g-1) and post-baseline (GM = 23.2 µg g-1). In multiple regression models, at baseline, industry significantly predicted increased total BPACR (P = 0.0248); post-baseline, handling BPA containers (P = 0.0035), taking ≥3 process/bulk samples with BPA (P = 0.0002) and wearing a Tyvek® coverall (P = 0.0042) significantly predicted increased total BPACR (after adjusting for total BPACR at baseline, time point, and body mass index). Conclusion Several work-related factors, including industry, job, and certain tasks performed, were associated with increased urinary total BPACR concentrations in this group of manufacturing workers. The potential for BPA-related health effects among these workers is unknown.

Di(isononyl)cyclohexane-1,2-dicarboxylate (DINCH), a non-phthalate plasticizer, was introduced commercially in 2002 as an alternative to ortho-phthalate esters because of its favorable toxicological profile. However, the potential health effects from DINCH exposure remain largely unknown. We explored the associations between urinary concentrations of metabolites of DINCH on markers of ovarian response among women undergoing in vitro fertilization (IVF) treatments. Between 2011 and 2015, 113 women enrolled a prospective cohort study at the Massachusetts General Hospital Fertility Center and provided up to two urine samples prior to oocyte retrieval. The urinary concentrations of two DINCH metabolites, cyclohexane-1,2-dicarboxylic acid monohydroxy isononyl ester (MHiNCH) and cyclohexane-1,2-dicarboxylic acid monocarboxyisooctyl ester (MCOCH), were quantified by isotope dilution tandem mass spectrometry. We used generalized linear mixed models to evaluate the association between urinary metabolite concentrations and markers of ovarian response, accounting for multiple IVF cycles per woman via random intercepts. On average, women with detectable urinary MHiNCH concentrations, as compared to those below LOD, had a lower estradiol levels (-325 pmol/l, p=0.09) and number of retrieved oocytes (-1.8, p=0.08), with a stronger association among older women. However, urinary MHiNCH concentrations were unrelated to mature oocyte yield and endometrial wall thickness. In conclusion, we found suggestive negative associations between urinary MHiNCH concentrations and peak estradiol levels and number of total oocyte yields. This is the first study evaluating the effect of DINCH exposure on human reproductive health and raises the need for further experimental and epidemiological studies to better understand the potential effects of this chemical on health.

Background: Identifying factors that impair bone accrual during childhood is a critical step toward osteoporosis prevention. Exposure to per- and polyfluoroalkyl substances (PFASs) has been associa...

Background Bisphenol A (BPA) has been linked with pediatric asthma development and allergic airway inflammation in animal models. Whether exposure to BPA or its structural analogs bisphenol S (BPS) and bisphenol F (BPF) is associated with asthma morbidity remains unknown. Objective We examined associations between bisphenols and morbidity due to pediatric asthma. Methods We quantified concentrations of BPA, BPS, and BPF in 660 urine samples from 148 predominantly low-income, African American children (aged 5-17 years) with established asthma. We used biobanked biospecimens and data on symptoms, health care utilization, and pulmonary function and inflammation that were collected every 3 months over the course of a year. We used generalized estimating equations to examine associations between concentrations or detection of urinary bisphenols and morbidity outcomes and assessed heterogeneity of associations by sex. Results We observed consistent positive associations between BPA exposure and measures of asthma morbidity. For example, we observed increased odds of general symptom days (adjusted odds ratio [aOR] = 1.40 [95% C = 1.02-1.92]), maximal symptom days (aOR = 1.36 [95% CI = 1.00-1.83]), and emergency department visits (aOR = 2.12 [95% CI =1.28-3.51]) per 10-fold increase in BPA concentration. We also observed evidence of sexually dimorphic effects; BPA concentrations were associated with increased odds of symptom days and health care utilization only among boys. Findings regarding BPS and BPF did not consistently point to associations with asthma symptoms or health care utilization. Conclusion We found evidence to suggest that BPA exposure in a predominantly low-income, minority pediatric cohort is associated with asthma morbidity and that associations may differ by sex. Our findings support additional studies, given the high pediatric asthma burden and widespread exposure to BPA in the United States.

The ZnO/Ag composite photocatalysts were prepared via the deposition of Ag on the surface of the grassy ZnO by a simple immersion reduction method. The dosage of Ag in the composites was adjusted by the concentration of Ag ions, immersion time and the content of the reducing agent. The grassy ZnO substrate presented a hexagonal wurtzite structure and a uniform dispersion. The band gap of the ZnO/Ag composites was decreased than that of grassy ZnO due to the surface plasma resonance (SPR) effect caused by Ag modification. The photocurrent response of the composites with proper amount of Ag loading was greatly improved by the SPR effect of Ag and subsequently enhanced light absorption, which resulted in the separation of electron-hole pairs in the near-surface region of the neighboring semiconductor. The ZnO/Ag composites had excellent photocatalytic efficiency in decolorization of RhB under UV irradiation.

Perfluoroalkyl substances (PFAS) were shown to be immunotoxic in laboratory animals. There is some epidemiological evidence that PFAS exposure is inversely associated with vaccine-induced antibody concentration. We examined immune response to vaccination with FluMist intranasal live attenuated influenza vaccine in relation to four PFAS (perfluorooctanoate, perfluorononanoate, perfluorooctane sulfonate, perfluorohexane sulfonate) serum concentrations among 78 healthy adults vaccinated during the 2010 – 2011 influenza season. We measured anti-A H1N1 antibody response and cytokine and chemokine concentrations in serum pre-vaccination, 3 days post-vaccination, and 30 days post-vaccination. We measured cytokine, chemokine, and mucosal IgA concentration in nasal secretions 3 days post-vaccination and 30 days post-vaccination. Adults with higher PFAS concentrations were more likely to seroconvert after FluMist vaccination as compared to adults with lower PFAS concentrations. The associations, however, were imprecise and few participants seroconverted as measured either by hemagglutination inhibition (9%) or immunohistochemical staining (25%). We observed no readily discernable or consistent pattern between PFAS concentration and baseline cytokine, chemokine, or mucosal IgA concentration, or between PFAS concentration and change in these immune markers between baseline and FluMist-response states. The resuts of this study do not support a reduced immune response to FluMist vaccination among healthy adults in relation to serum PFAS concentration. Given the study’s many limitations, however, it does not rule out impaired vaccine response to other vaccines or vaccine components in either children or adults.

Single crystal Zn-doped SnO 2 (Zn–SnO 2 ) nanorods with cone-shaped tips (~25 nm) on copper foil were synthesized by an organic-free hydrothermal method. The effects of the Zn doping on the morphology, microstructure and field-emission (FE) properties of Zn–SnO 2 were investigated. It is found that the Zn doping play an important role in tuning the morphology and size of the SnO 2 nanorods. The turn-on fields of SnO 2 and Zn–SnO 2 nanorods were 3.16 and 2.37 V/μm, and field enhancement factors (β) were 960 and 3352, respectively. The enhanced FE property is due to the tapered structures of nanorods with sharp tips and the weak screening effect, and the better electrical contact between conductive copper substrate and field emitters.