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1.
Wei Sheng Yan Jiu ; 53(1): 102-108, 2024 Jan.
Artigo em Chinês | MEDLINE | ID: mdl-38443180

RESUMO

OBJECTIVE: To establish a method for determination of perchlorate and chlorate in drinks by ultra-performance liquid chromatography-tandem mass spectrometry(UPLC-MS/MS) based on isotopic internal standard method. METHODS: The perchlorate and chlorate residue in liquid drinks were extracted with methanol, in solid drinks with acetic acid solution, then centrifuged. The supernatant was cleaned-up with PSA/C18 cleanup tube. The separation of perchlorate and chlorate was carried out on a Acquity CSH fluorophenyl column(100 mm×2.1mm, 1.7 µm) and the detection was performed with tandem mass spectrometry with internal standard method for quantification. RESULTS: The peak area ratio of perchlorate and chlorate had a good linear relationship with their mass concentration within their respective linear ranges, with correlation coefficients(r) greater than 0.999. The limits of detection of perchlorate and chlorate were 0.2and 1 µg/L respectively and the limits of quantification were 0.5 and 3 µg/L respectively. The mean recoveries of two compounds were from 84.0% to 105.5% with relative standard deviations from 4.2% to 17.0% and 82.7% to 112.1% with relative standard deviations from 5.5% to 18.4%(n=6), respectively. The perchlorates in 11 kinds of beverage samples were 0.53-4.12 µg/L, chlorates were 3.27-61.86 µg/L. CONCLUSION: This method is simple, sensitive, accurate and reliable, which is suitable for the determination of perchlorate and chlorate in drinks.


Assuntos
Cloratos , Percloratos , Cromatografia Líquida , Espectrometria de Massas em Tandem
2.
Appl Microbiol Biotechnol ; 108(1): 266, 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38498184

RESUMO

Lipoxygenases (LOXs) catalyze dioxygenation of polyunsaturated fatty acids (PUFAs) into fatty acid hydroperoxides (FAHPs), which can be further transformed into a number of value-added compounds. LOXs have garnered interest as biocatalysts for various industrial applications. Therefore, a high-throughput LOX activity assay is essential to evaluate their performance under different conditions. This study aimed to enhance the suitability of the ferrous-oxidized xylenol orange (FOX) assay for screening LOX activity across a wide pH range with different PUFAs. The narrow linear detection range of the standard FOX assay restricts its utility in screening LOX activity. To address this, the concentration of perchloric acid in the xylenol orange reagent was adjusted. The modified assay exhibited a fivefold expansion in the linear detection range for hydroperoxides and accommodated samples with pH values ranging from 3 to 10. The assay could quantify various hydroperoxide species, indicating its applicability in assessing LOX substrate preferences. Due to sensitivity to pH, buffer types, and hydroperoxide species, the assay required calibration using the respective standard compound diluted in the same buffer as the measured sample. The use of correction factors is suggested when financial constraints limit the use of FAHP standard compounds in routine LOX substrate preference analysis. FAHP quantification by the modified FOX assay aligned well with results obtained using the commonly used conjugated diene method, while offering a quicker and broader sample pH range assessment. Thus, the modified FOX assay can be used as a reliable high-throughput screening method for determining LOX activity. KEY POINTS: • Modifying perchloric acid level in FOX reagent expands its linear detection range • The modified FOX assay is applicable for screening LOX activity in a wide pH range • The modified FOX assay effectively assesses substrate specificity of LOX.


Assuntos
Peróxido de Hidrogênio , Percloratos , Fenóis , Sulfóxidos , Ensaios de Triagem em Larga Escala , Xilenos/química , Lipoxigenases
3.
J Inorg Biochem ; 255: 112538, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38547785

RESUMO

A novel hexadentate bishydrazone ligand, 1,10-bis(di(2-pyridyl)ketone) adipic acid dihydrazone (H2L1) is synthesized and characterized. With copper perchlorate as a catalytic oxidant, the ligand undergoes oxidative cyclisation and resulted in the formation of an unusual copper complex [Cu(L1a)2Cl]ClO4 (1), where L1a is 3-(2-pyridyl)triazolo[1,5-a]-pyridine. The Cu(II) complex was characterized physicochemically, while the molecular structure was confirmed by single crystal X- ray diffraction. In the complex cation, copper(II) is in a distorted trigonal bipyramidal coordination environment, surrounded by two triazolo nitrogen atoms and two pyridyl nitrogen atoms of L1a and a chloride atom. The relevant non covalent intermolecular interactions of the complex quantified using Hirshfeld surface analysis reveals that the O···H/ H···O (27.2%) contacts has the highest contribution. The solution phase bandgaps of the compounds were calculated using Tauc plot, whereas the solid-state band gaps were calculated by Kubelka-Munk model. DFT studies of the compounds indicate that the theoretical calculations corroborate with the experimental data. DPPH antioxidant activity assay of the synthesized compounds showed that the proligand H2L1 has a lower IC50 value (24.1 µM) than that of complex 1 (29.7 µM). The in vitro antibacterial activity was evaluated against Escherichia coli and Staphylococcus aureus, which revealed that complex 1 have excellent activity against E. coli, much as the standard ciprofloxacin. The cytotoxic efficacy investigation of the compounds against A549 (lung) adenocarcinoma cells suggested that H2L1 has more anticancer activity (IC50 value of 149.08 µM) than that of complex 1(IC50 value of 176.70 µM).


Assuntos
Cobre , Compostos Organometálicos , Cobre/química , Compostos Organometálicos/química , Ligantes , Percloratos , Escherichia coli , Nitrogênio , Estresse Oxidativo , Cristalografia por Raios X
4.
Ophthalmic Plast Reconstr Surg ; 40(2): 198-200, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38427834

RESUMO

PURPOSE: To investigate the ocular safety profile of topical perchlorate as a potential preventive treatment for nasolacrimal obstruction associated with excessive use of radioactive iodine therapy. METHODS: Nine Wistar male rats (18 eyes) were randomly assigned to receive an ocular application (topical eye drop on the OD, 3 times a day for 5 days) consisting of either: 1) sterile saline solution, 2) 30 mg/ml NaClO4 or 3) 30 mg/ml KClO4. The rat eyes were examined daily for corneal cloudiness/clarity, discharge, mucous secretions, conjunctival injection, eyelid erythema, and/or changes in behavior. Seven days after the first dose, the rats were euthanized and OU were harvested, fixed, embedded in paraffin, and stained with H&E and Masson's trichrome using standard techniques. RESULTS: The data collected over the 7 days revealed no behavior changes or ocular complications in any of the 3 study groups. Pathologic analysis of the corneas revealed normal findings on all groups without signs of inflammation, fibrosis, or any other abnormality, and no difference between the treated and control eyes. CONCLUSIONS: The findings of this study suggest that the use of topical perchlorate is safe to use on eyes in high concentrations. The efficacy of this compound in minimizing fibrosis of the nasolacrimal sac and duct warrants further study.


Assuntos
Radioisótopos do Iodo , Neoplasias da Glândula Tireoide , Masculino , Ratos , Animais , Ratos Wistar , Percloratos/toxicidade , Córnea , Fibrose
5.
Front Immunol ; 15: 1318737, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38495893

RESUMO

Background: Perchlorates, nitrates, and thiocyanates are prevalent environmental chemicals. Their potential association with arthritis remains unexplored. This study aimed to investigate the link between perchlorate, nitrate, and thiocyanate exposure and arthritis, as well as the potential role of inflammation in this context. Methods: Utilizing the National Health and Nutrition Examination Survey (NHANES) data spanning from 2005 to 2016, the study enrolled 6597 participants aged 20-59 (young and middle-aged), of which 1045 had arthritis. Employing multivariate logistic regression modeling, multiple linear regression models, restricted cubic spline analysis, Bayesian kernel machine regression (BKMR) modeling, and mediation analysis, we assessed these relationships. Results: There was a significant positive association between elevated urinary thiocyanate levels and arthritis risk [1.19 (1.11, 1.28)]. This association held true across subgroups of osteoarthritis (OA) [1.24 (1.10, 1.40)] and rheumatoid arthritis (RA) [1.33 (1.15, 1.55)]. Thiocyanate levels displayed a dose-dependent relationship with arthritis risk, showing a linear trend (nonlinear P > 0.05). Conversely, perchlorate and nitrate did not exhibit associations with arthritis risk. BKMR outcomes highlighted a positive correlation between a mixture of perchlorate, nitrate, and thiocyanate and arthritis risk, with thiocyanate being the predominant predictors. Moreover, BKMR and generalized linear model analyses unveiled no significant synergistic effect of urinary perchlorate, nitrate, and thiocyanate on arthritis risk. Furthermore, thiocyanate exposure has been linked to elevated levels of inflammatory indicators (white blood cell, neutrophils, lymphocytes, and systemic immune-inflammatory index (SII)). Conclusion: Heightened thiocyanate exposure may be linked to elevated arthritis risk, either single or in combined effects. Additionally, thiocyanate exposure is associated with heightened inflammation levels.


Assuntos
Artrite , Nitratos , Adulto , Pessoa de Meia-Idade , Humanos , Nitratos/efeitos adversos , Nitratos/urina , Tiocianatos/urina , Percloratos/efeitos adversos , Percloratos/urina , Inquéritos Nutricionais , Teorema de Bayes , Inflamação/epidemiologia , Artrite/epidemiologia
6.
J Hazard Mater ; 466: 133683, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38310847

RESUMO

The conventional perchlorate (ClO4-) reduction typically necessitates anaerobic conditions. However, in this study, we observed efficient ClO4- reduction using CH4 as the electron donor in a microaerobic environment. The maximum ClO4- removal flux of 2.18 g/m2·d was achieved in CH4-based biofilm. The kinetics of ClO4- reduction showed significant differences, with trace oxygen increasing the reduction rate of ClO4-, whereas oxygen levels exceeding 2 mg/L decelerated the ClO4- reduction. In the absence of exogenous oxygen, anaerobic methanotrophic (ANME) archaea contribute more than 80% electrons through the reverse methanogenesis pathway for ClO4- reduction. Simultaneously, microorganisms activate CH4 by utilizing oxygen generated from chlorite (ClO2-) disproportionation. In the presence of exogenous oxygen, methane oxidizers predominantly consume oxygen to drive the aerobic oxidation of methane. It is indicated that methane oxidizers and perchlorate reducing bacteria can form aggregates to resist external oxygen shocks and achieve efficient ClO4- reduction under microaerobic condition. These findings provide new insights into biological CH4 mitigation and ClO4- removal in hypoxic environment.


Assuntos
Metano , Percloratos , Metano/metabolismo , Percloratos/metabolismo , Archaea/metabolismo , Oxirredução , Anaerobiose , Oxigênio/metabolismo
7.
Environ Sci Pollut Res Int ; 31(6): 8510-8518, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38182951

RESUMO

Chlorate and perchlorate are emerging pollutants that may interfere with thyroid function. Since they are highly water soluble, chlorate and perchlorate in tea leaves cause health concerns but have scarcely been studied. In this study, chlorate and perchlorate concentrations in 216 tea samples from different regions of China were determined. Perchlorate was detected in all the samples with a median concentration of 44.1 µg kg-1, while the chlorate detection frequency was 15.7%. We observed regional differences in perchlorate contents in tea leaves, with the highest quantity found in the central region of China. Except for dark tea, the concentration of perchlorate in tea infusions decreased with the increased number of times the tea leaves were brewed. The hazard quotients (HQs) of chlorate and perchlorate in all the samples were less than 1, suggesting negligible health risks caused by these pollutants from tea consumption. To the best of our knowledge, this is the first study to investigate chlorate and perchlorate contamination in tea infusions by simulating brewing behavior.


Assuntos
Cloratos , Poluentes Ambientais , Humanos , Cloratos/análise , Percloratos/análise , Chá , China
8.
Int J Biol Macromol ; 255: 128125, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37984571

RESUMO

Transforming lignin into aromatic monomers is critically attractive to develop green and sustainable energy supplies. However, the usage of the additional catalysts like metal or base/acid is commonly limited by the caused repolymerized and environmental issues. The key step is to mediate electron transfer in lignin to trigger lignin C-C/C-O bonds cleavage without the catalysts mentioned above. Here, we report that the ionic liquids [BMim][ClO4] was found to trigger lignin electron transfer to cleave the C-C/C-O bonds for aromatic monomers without any additional catalyst. The proton transfer from [BMim]+ to [ClO4]- could polarize the anion and decrease its structure stability, upon which the active hydroxyl radical generated and induced lignin C-C/C-O bonds fragmentation via free radical-mediated routes with the assistance of photothermal synergism. About 4.4 wt% yields of aromatic monomers, mainly composed of vanillin and acetosyringone, are afforded in [BMim][ClO4] under UV-light irradiation in the air at 80 °C. This work opens the way to produce value-added aromatic monomers from lignin using an eco-friendly, energy-efficient, and simple route that may contribute to the sustainable utilization of renewable natural resources.


Assuntos
Líquidos Iônicos , Líquidos Iônicos/química , Lignina/química , Álcalis , Percloratos , Catálise
9.
J Phycol ; 60(1): 185-194, 2024 02.
Artigo em Inglês | MEDLINE | ID: mdl-38156502

RESUMO

The mechanism of perchlorate resistance of the desert cyanobacterium Chroococcidiopsis sp. CCMEE 029 was investigated by assessing whether the pathways associated with its desiccation tolerance might play a role against the destabilizing effects of this chaotropic agent. During 3 weeks of growth in the presence of 2.4 mM perchlorate, an upregulation of trehalose and sucrose biosynthetic pathways was detected. This suggested that in response to the water stress triggered by perchlorate salts, these two compatible solutes play a role in the stabilization of macromolecules and membranes as they do in response to dehydration. During the perchlorate exposure, the production of oxidizing species was observed by using an oxidant-sensing fluorochrome and determining the expression of the antioxidant defense genes, namely superoxide dismutases and catalases, while the presence of oxidative DNA damage was highlighted by the over-expression of genes of the base excision repair. The involvement of desiccation-tolerance mechanisms in the perchlorate resistance of this desert cyanobacterium is interesting since, so far, chaotropic-tolerant bacteria have been identified among halophiles. Hence, it is anticipated that desert microorganisms might possess an unrevealed capability of adapting to perchlorate concentrations exceeding those naturally occurring in dry environments. Furthermore, in the endeavor of supporting future human outposts on Mars, the identified mechanisms might contribute to enhance the perchlorate resistance of microorganisms relevant for biologically driven utilization of the perchlorate-rich soil of the red planet.


Assuntos
Cianobactérias , Percloratos , Humanos , Percloratos/metabolismo , Cianobactérias/genética , Cianobactérias/metabolismo , Estresse Oxidativo
10.
Appl Microbiol Biotechnol ; 108(1): 22, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38159121

RESUMO

Three new strains of dissimilatory perchlorate-reducing bacteria (DPRB), QD19-16, QD1-5, and P3-1, were isolated from an active sludge. Phylogenetic trees based on 16S rRNA genes indicated that QD19-16, QD1-5, and P3-1 belonged to Brucella, Acidovorax, and Citrobacter, respectively, expanding the distribution of DPRB in the Proteobacteria. The three strains were gram-negative and facultative anaerobes with rod-shaped cells without flagella, which were 1.0-1.6 µm long and 0.5-0.6 µm wide. The three DPRB strains utilized similar broad spectrum of electron donors and acceptors and demonstrated a similar capability to reduce perchlorate within 6 days. The enzyme activity of perchlorate reductase in QD19-16 toward chlorate was higher than that toward perchlorate. The high sequence similarity of the perchlorate reductase operon and chlorite dismutase genes in the perchlorate reduction genomic islands (PRI) of the three strains implied that they were monophyletic origin from a common ancestral PRI. Two transposase genes (tnp1 and tnp2) were found in the PRIs of strain QD19-16 and QD1-5, but were absent in the strain P3-1 PRI. The presence of fragments of IR sequences in the P3-1 PRI suggested that P3-1 PRI had previously contained these two tnp genes. Therefore, it is plausible to suggest that a common ancestral PRI transferred across the strains Brucella sp. QD19-16, Acidovorax sp. QD1-5, and Citrobacter sp. P3-1 through horizontal gene transfer, facilitated by transposases. These results provided a direct evidence of horizontal gene transfer of PRI that could jump across phylogenetically unrelated bacteria through transposase. KEY POINTS: • Three new DPRB strains can effectively remove high concentration of perchlorate. • The PRIs of three DPRB strains are acquired from a single ancestral PRI. • PRIs are incorporated into different bacteria genome through HGT by transposase.


Assuntos
Ilhas Genômicas , Percloratos , Filogenia , Oxirredução , Transferência Genética Horizontal , RNA Ribossômico 16S/genética , Bactérias/genética , Oxirredutases/genética , Ecossistema , Transposases/genética
11.
Chemosphere ; 346: 140662, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37949182

RESUMO

Perchlorate, a widespread environmental contaminant originating from various industrial applications, agricultural practices, and natural sources, poses potential risks to ecosystems and human health. While previous studies have highlighted its influence on the thyroid endocrine system and its impact on gonadal maturation, reproduction, and sex hormone synthesis, the specific interplay between thyroid and steroid hormones, in this context, remains largely unexplored. Therefore, this study was undertaken to investigate the adverse effects and underlying mechanisms triggered by exposure to sodium perchlorate (SP) on reproductive endocrine activity in zebrafish. For 21 d, the fish were exposed to test SP concentrations (0, 3, 30, 300 mg/L), which were determined based on the exposure concentrations that induced various toxic effects in the fish, considering naturally occurring concentrations. Exposure to SP, except at 3 mg/L in males, significantly decreased the production of thyroid hormone (TH) in both female and male zebrafish. Moreover, gonadal steroid levels were markedly reduced in both sexes. The expression of hepatic vitellogenin (VTG) mRNA in female zebrafish was significantly decreased, whereas aromatase activity in male zebrafish was significantly elevated in the SP exposure groups. The reduced levels of THs and gonadal steroid hormones were strongly correlated. Abnormal responses to SP exposure led to reduced reproductive success in the 300 mg/L SP exposure group. These findings indicate that prolonged and continuous exposure to a specific concentration of SP may lead to long-term reproductive problems in zebrafish, primarily through hormonal imbalances and suppression of hepatic VTG mRNA expression.


Assuntos
Poluentes Químicos da Água , Peixe-Zebra , Animais , Humanos , Feminino , Masculino , Peixe-Zebra/metabolismo , Percloratos/toxicidade , Percloratos/metabolismo , Glândula Tireoide/metabolismo , Saúde Reprodutiva , Ecossistema , Gônadas , Hormônios Esteroides Gonadais/metabolismo , Reprodução , Esteroides/metabolismo , RNA Mensageiro/metabolismo , Vitelogeninas/metabolismo , Poluentes Químicos da Água/metabolismo
12.
J Hazard Mater ; 465: 133226, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38103290

RESUMO

The release and accumulation of perchlorate into the environment have raised concerns about safety to food, however, the dietary risk of perchlorate in honey have not yet received attention. Herein, we investigated the pollution characteristics and assessed the human health risks of perchlorate in honey from China. A total of 151 honey samples collected from 20 provinces of China were analyzed, and overall detection frequencies was 95.4 %. The levels of perchlorate ranged from below limit of quantitation to 612 µg/kg, with a mean value of 34.5 µg/kg. Lychee honey samples had the highest mean perchlorate concentration (163 µg/kg). The mean concentration of perchlorate in the honey samples produced in South China was significantly higher than that in honey from Southwest China, East China and North China (P < 0.05). The health risk assessment showed that mean hazard quotient (HQ) values of different honey for children (ranged from 0.0108 to 0.400) and adults (ranged from 0.0123 to 0.453) were less than 1. This result indicated that mean pollution levels of perchlorate in various honey were unlikely to pose health risk. However, perchlorate concentrations in two lychee honey samples had associated HQ values were >1, suggesting potential health risks. This work not only offers valuable information for honey consumer, but also important reference for comparison of honey samples in the future. ENVIRONMENTAL IMPLICATION: Perchlorate contamination has become a hot environmental issue in connection with human health due to its potential thyroid toxicity and widespread occurrence in environment and foods. Honey not only was widely beloved by consumers worldwide but also considered a potential indicator of environmental pollution. Here, a national investigation and risk assessment of perchlorate levels in different types of honey from China was conducted. The results describe the perchlorate contamination were extensive in honey samples, mean levels of perchlorate in various honey were unlikely to cause health risks. However, significantly high level of contamination in lychee honey should be of concern.


Assuntos
Mel , Criança , Adulto , Humanos , Percloratos , Poluição Ambiental , China , Medição de Risco
13.
Toxicol Sci ; 198(1): 113-127, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38145495

RESUMO

The environmental contaminant perchlorate impairs the synthesis of thyroid hormones by reducing iodine uptake into the thyroid gland. Despite this known action, moderate doses of perchlorate do not significantly alter serum thyroid hormone in rat pups born to exposed dams. We examined perchlorate dosimetry and responsivity of the thyroid gland and brain in offspring following maternal exposure to perchlorate. Pregnant rat dams were delivered perchlorate in drinking water (0, 30, 100, 300, 1000 ppm) from gestational day 6 to postnatal day (PN) 21. Perchlorate was present in the placenta, milk, and serum, the latter declining in pups over the course of lactation. Serum and brain thyroid hormone were reduced in pups at birth but recovered to control levels by PN2. Dramatic upregulation of Nis was observed in the thyroid gland of the exposed pup. Despite the return of serum thyroid hormone to control levels by PN2, expression of several TH-responsive genes was altered in the PN14 pup brain. Contextual fear learning was unimpaired in the adults, supporting previous reports. Declining levels of serum perchlorate and a profound upregulation of Nis gene expression in the thyroid gland are consistent with the rapid return to the euthyroid state in the neonate. However, despite this recovery, thyroid hormone insufficiencies in serum and brain beginning in utero and present at birth appear sufficient to alter TH action in the fetus and subsequent trajectory of brain development. Biomarkers of that altered trajectory remain in the brain of the neonate, demonstrating that perchlorate is not devoid of effects on the developing brain.


Assuntos
Compostos de Amônio Quaternário , Resiliência Psicológica , Glândula Tireoide , Gravidez , Feminino , Ratos , Animais , Percloratos/toxicidade , Percloratos/metabolismo , Animais Recém-Nascidos , Hormônios Tireóideos
14.
Aquat Toxicol ; 265: 106767, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37972501

RESUMO

Perchlorate, as an endocrine-disrupting chemical (EDC), is largely produced and used in the military, fireworks, fertilizers, and other industries and widely exists in water. Although perchlorate is known to destroy the normal function of thyroid hormones (THs) in amphibians and interfere with their growth and development, the impact of TH levels caused by sodium perchlorate (NaClO4) on endochondral ossification and skeletal development is poorly investigated, and the underlying molecular mechanism has not been clarified. The present study aimed to explore the potential effects of NaClO4 and exogenous thyroxine (T4) on the skeletal development of Rana chensinensis tadpoles and elucidate the related molecular mechanisms. Our results showed that histological changes occurred to the femur and tibia-fibula of tadpoles raised in 250 µg/L NaClO4 and 5 µg/L exogenous T4, and the length of their hindlimbs was significantly reduced. In addition, exogenous T4 exposure significantly interfered with the expression of Dio3, TRß, MMP9, MMP13, and Runx2, inhibiting the endochondral ossification process. Therefore, we provide robust evidence that the changes in TH levels caused by NaClO4 and exogenous T4 will adversely affect the endochondral ossification and skeletal development of R. chensinensis tadpoles.


Assuntos
Osteogênese , Poluentes Químicos da Água , Animais , Larva , Percloratos/toxicidade , Poluentes Químicos da Água/toxicidade , Ranidae , Metamorfose Biológica
15.
Environ Sci Technol ; 57(49): 20480-20493, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-38015815

RESUMO

Studies about the impacts of maternal exposure to perchlorate, thiocyanate, and nitrate on offspring neurodevelopment are scarce. Based on a birth cohort in China, 1,028 mothers provided urine samples at three trimesters for determination of the three target analytes, and their offspring neurodevelopment was evaluated at 2 years old. Associations of maternal exposure to the three chemicals with offspring neurodevelopment were estimated using three statistical methods. Trimester-specific analyses using generalized estimating equation models showed that double increment of thiocyanate and nitrate during the first trimester was associated with 1.56 (95% CI: -2.82, -0.30) and 1.22 (-2.40, -0.03) point decreases in the offspring mental development index (MDI), respectively. Weighted quantile sum (WQS) regression analyses showed that the mixture exposure at the first and second trimesters was negatively associated with the offspring MDI (ß = -2.39, 95% CI: -3.85, -0.93; ß = -1.75, 95% CI: -3.04, -0.47, respectively) and thiocyanate contributed the most to the association (65.0 and 91.6%, respectively). Bayesian kernel machine regression analyses suggested an inverted U-shape relationship of maternal urinary thiocyanate with the offspring MDI. These findings suggested that prenatal exposure to the three chemicals (at current levels), especially thiocyanate and nitrate, may impair neurodevelopment. Early pregnancy seems to be the sensitive window.


Assuntos
Nitratos , Percloratos , Criança , Gravidez , Feminino , Humanos , Pré-Escolar , Nitratos/urina , Estudos de Coortes , Percloratos/urina , Tiocianatos/urina , Teorema de Bayes , Exposição Materna
16.
Chemosphere ; 345: 140467, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37852377

RESUMO

Perchlorate, nitrate, and thiocyanate are well-known inhibitors of iodide uptake and thyroid-disrupting chemicals. Widespread human exposure to them has been identified, whereas studies on their internal exposure levels among Chinese pregnant women are scarce and factors associated with them are not well recognized. The objective of this study is to determine their levels and identify the associated factors among pregnant women (n = 1120), based on a prospective birth cohort in Wuhan, central China, using repeated urine samples of three trimesters. Urinary perchlorate, thiocyanate, and nitrate were 100% detected in the samples, and specific gravity-adjusted median concentrations of them in all the samples were 12.6 ng/mL, 367 ng/mL, and 63.7 µg/mL, respectively. Their concentrations were weakly-to-moderately correlated with each other, with Spearman correlation coefficients ranging from 0.27 to 0.54. Poor reproducibility were observed for the three analytes over the three trimesters, with intraclass correlation coefficient of 0.07, 0.19, 0.04 for perchlorate, thiocyanate, and nitrate, respectively. The women who were overweight or used tap water as drinking water had significantly higher perchlorate concentrations, while those with excessive gestational weight gain had significantly higher thiocyanate concentrations (p < 0.05). The women with a college degree or above had lower nitrate concentrations (p < 0.05). Meanwhile, the median concentration of perchlorate in urine samples collected in spring, thiocyanate in those collected in winter, and nitrate in those collected in autumn, was significantly higher compared to their median concentrations in the samples collected in other three seasons (p < 0.05), respectively. Urinary perchlorate and nitrate concentrations of pregnant women in this study were higher than the concentrations of pregnant women in other countries, while thiocyanate concentrations were lower than that of most other countries. This study suggested potential covariates for future epidemiological analyses.


Assuntos
Nitratos , Percloratos , Gestantes , Tiocianatos , Feminino , Humanos , Gravidez , População do Leste Asiático , Nitratos/urina , Percloratos/urina , Estudos Prospectivos , Reprodutibilidade dos Testes , Fatores de Risco , Tiocianatos/urina , Aumento de Peso
17.
Toxicol Appl Pharmacol ; 479: 116733, 2023 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-37866708

RESUMO

Despite the number of in vitro assays that have been recently developed to identify chemicals that interfere with the hypothalamic-pituitary-thyroid axis (HPT), the translation of those in vitro results into in vivo responses (in vitro to in vivo extrapolation, IVIVE) has received limited attention from the modeling community. To help advance this field a steady state biologically based dose response (BBDR) model for the HPT axis was constructed for the pregnant rat on gestation day (GD) 20. The BBDR HPT axis model predicts plasma levels of thyroid stimulating hormone (TSH) and the thyroid hormones, thyroxine (T4) and triiodothyronine (T3). Thyroid hormones are important for normal growth and development of the fetus. Perchlorate, a potent inhibitor of thyroidal uptake of iodide by the sodium iodide symporter (NIS) protein, was used as a case study for the BBDR HPT axis model. The inhibitory blocking of the NIS by perchlorate was associated with dose-dependent steady state decreases in thyroid hormone production in the thyroid gland. The BBDR HPT axis model predictions for TSH, T3, and T4 plasma concentrations in pregnant Sprague Dawley (SD) rats were within 2-fold of observations for drinking water perchlorate exposures ranging from 10 to 30,000 µg/kg/d. In Long Evans (LE) pregnant rats, for both control and perchlorate drinking water exposures, ranging from 85 to 82,000 µg/kg/d, plasma thyroid hormone and TSH concentrations were predicted within 2 to 3.4- fold of observations. This BBDR HPT axis model provides a successful IVIVE template for thyroid hormone disruption in pregnant rats.


Assuntos
Água Potável , Percloratos , Gravidez , Feminino , Ratos , Animais , Percloratos/toxicidade , Ratos Sprague-Dawley , Ratos Long-Evans , Hormônios Tireóideos , Tiroxina/metabolismo , Tireotropina
18.
Front Public Health ; 11: 1260612, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37860794

RESUMO

Objective: To investigate the association between the concentration of perchlorate in drinking water and the height and weight of children and adolescents in Sichuan Province. Methods: Perchlorate in the drinking water of 24 counties in Sichuan Province from 2021 to 2022 was detected and analyzed, 66 drinking water samples were collected, and the content of perchlorate in drinking water during the wet season and dry season was detected by ultra-high performance liquid chromatography in series. The linear mixed effect model was used to estimate the relationship between perchlorate in drinking water and the height and weight of 144,644 children and adolescents, and 33 pieces of local average wage data were used as confounding factors for quality control. Results: After controlling the age, gender, and local economic situation, we found that the concentration of perchlorate in drinking water increased by 10 µg/L is associated with a 1.0 cm decrease in height and a 1.6 kg decrease in weight in children and adolescents (p < 0.05). Conclusion: The concentration of perchlorate in drinking water may be negatively correlated with the height and weight of children.


Assuntos
Água Potável , Poluentes Químicos da Água , Criança , Humanos , Adolescente , Estudos Transversais , Percloratos , Estudos Retrospectivos , Poluentes Químicos da Água/análise , China
19.
Environ Sci Pollut Res Int ; 30(55): 117871-117880, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-37875760

RESUMO

In this work, a new coating of boron-doped diamond ultra-nanocrystalline (U-NBDD), tailored to prevent massive formation of perchlorates during disinfection, is evaluated as electrode for the reclaiming of treated secondary wastewater by the electrochemically assisted disinfection process. Results obtained are compared to those obtained by using a standard electrode (STD) that was evaluated as a standard in previous research showing outstanding performance for this application. First tests were carried out to evaluate the chlorine speciation obtained after the electrolysis of synthetic chloride solutions at two different ranges of current densities. Concentrations of hypochlorite obtained using the U-NBDD anode at 25 mA cm-2 were 1.5-fold higher, outperforming STD anode; however, at 300 mA cm-2, an overturn on the behavior of anodes occurs where the amount of hypochlorite produced on STD anode was 1.5-fold higher. Importantly, at low current density the formation of chlorates and perchlorates is null using U-NBDD. Then, the disinfection of the real effluent of the secondary clarifier of a municipal wastewater treatment facility is assessed, where inactivation of Escherichia coli is achieved at low charge applied per volume electrolyzed (0.08 A h L-1) at 25 mA cm-2 using the U-NBDD. These findings demonstrate the appropriateness of the strategy followed in this work to obtain safer electro-disinfection technologies for the reclaiming of treated wastewater.


Assuntos
Águas Residuárias , Poluentes Químicos da Água , Diamante/química , Desinfecção/métodos , Ácido Hipocloroso , Percloratos , Eletrólise/métodos , Eletrodos , Oxirredução , Poluentes Químicos da Água/química
20.
Astrobiology ; 23(9): 959-978, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37672714

RESUMO

Organic matter is actively searched on Mars with current and future space missions as it is a key to detecting potential biosignatures. Given the current harsh environmental conditions at the surface of Mars, many organic compounds might not be preserved over a long period as they are exposed to energetic radiation such as ultraviolet light, which is not filtered above 190 nm by the martian atmosphere. Moreover, the presence of strong oxidizing species in the regolith, such as perchlorate salts, might enhance the photodegradation of organic compounds of astrobiological interest. Because current space instruments analyze samples collected in the upper surface layer, it is necessary to investigate the stability of organic matter at the surface of Mars. Previous experimental studies have shown that uracil, a molecule relevant to astrobiology, is quickly photolyzed when exposed to UV radiation under the temperature and pressure conditions of the martian surface with an experimental quantum efficiency of photodecomposition (φexp) of 0.30 ± 0.26 molecule·photon-1. Moreover, the photolysis of uracil leads to the formation of more stable photoproducts that were identified as uracil dimers. The present work aims to characterize the additional effect of calcium perchlorate detected on Mars on the degradation of uracil. Results show that the presence of calcium perchlorate enhances the photodecomposition of uracil with φexp = 12.3 ± 8.3 molecule·photon-1. Although some of the photoproducts formed during these experiments are common to those formed from pure uracil only, the Fourier transformation infrared (FTIR) detection of previously unseen chemical functions such as alkyne C ≡ C or nitrile C ≡ N has shown that additional chemical species are formed in the presence of calcium perchlorate in the irradiated sample. This implies that the effect of calcium perchlorate on the photolysis of uracil is not only kinetic but also related to the nature of the photoproducts formed.


Assuntos
Cálcio , Marte , Fluoretos , Raios Ultravioleta , Percloratos , Temperatura , Meio Ambiente Extraterreno
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