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BACKGROUND: Exposure to different concentration levels of fatty acids (FAs) may have an impact on depression. However, previous studies using individual FAs may not reflect the performance of mixtures of various FAs, and the associations of FA patterns with depression remain unclear. METHODS: We conducted the cross-sectional analysis in 792 adults aged 18 and older with available serum FAs and depression screening data in the National Health and Nutrition Examination Survey (NHANES) 2011-2012. The serum concentrations of thirty FAs were measured using gas chromatography-mass spectrometry and their percentage compositions were subsequently calculated. Depression was defined as the Patient Health Questionnaire-9 score ≥ 10. We employed principal component analysis to derive serum FA patterns. We examined the association between these patterns and depression in the overall population and various subgroups through survey-weighted logistic regression. RESULTS: Four distinct patterns of serum FAs were identified: 'high eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA); low docosatetraenoic acid (DTA) and docosapentaenoic acid (DPA) n-6', 'high long-chain saturated FA and long chain FA', 'low median-chain saturated FA and myristoleic acid' and 'low capric acid and lauric acid; high gamma-linolenic acid (GLA) and stearidonic acid (SDA)' pattern. Individuals in the high tertile of 'high EPA and DHA; low DTA and DPA n-6' pattern score had 0.46 (95% CI: 0.22, 0.93) lower odds of developing depression compared to individuals in the lowest tertile after adjusting for confounders such as age, sex, physical activity and total energy intake, etc. The odds ratio (OR) of depression was increased in the population with the highest tertile of 'low capric acid and lauric acid; high GLA and SDA' pattern (OR: 2.45, 95% CI: 1.24, 4.83). In subgroup analyses, we observed that the association between 'high EPA and DHA; low DTA and DPA n-6' and depression persisted among specific demographic and lifestyle subgroups, including females, non-Mexican Americans, non-obese, those aged over 60 years, smokers and drinkers. Similarly, 'low capric acid and lauric acid; high GLA and SDA' showed stable associations in female, non-Mexican Americans and smokers. CONCLUSIONS: Serum FA patterns are associated with depression, and their relationships vary across sex, race, BMI, age, smoking and drinking subgroups, highlighting the importance of considering specific FA patterns within these demographic and lifestyle categories. Utilization of combined FA administration may serve as a mitigation measure against depression in these specific populations.
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Depressão , Ácidos Graxos , Inquéritos Nutricionais , Humanos , Feminino , Masculino , Depressão/sangue , Depressão/epidemiologia , Adulto , Pessoa de Meia-Idade , Ácidos Graxos/sangue , Estudos Transversais , Estados Unidos/epidemiologia , Ácidos Decanoicos/sangue , Ácido Eicosapentaenoico/sangue , Idoso , Ácidos Graxos Insaturados/sangue , Adulto Jovem , Adolescente , Análise de Componente PrincipalRESUMO
As a burgeoning pollutant, microplastics (MPs) has elicited global concern. However, ecological effects and mechanisms of MPs on plant-soil system are still poorly understood. In the present study, the impacts of polyvinyl chloride microplastics (PVC-MPs) on maize (Zea mays L.) seedlings growth and physiological traits and soil properties were discussed through a 30-day pot experiment. Results showed that PVC-MPs had greater toxicity effect on seedlings shoot biomass than root biomass. To defense the impact of PVC-MPs, the superoxide dismutase and catalase activities in seedlings leaf were stimulated. Moreover, the adhesion of MPs on soil particles increased, and soil microorganism, enzymes, and nutrients were altered significantly with increasing content of PVC-MPs. Notably, soil nitrate nitrogen decreased significantly with increasing content of PVC-MPs, whereas soil ammonium nitrogen was promoted under lower contents (0.1% and 1%) of PVC-MPs. Redundancy analysis indicated that soil nitrate nitrogen and ammonium nitrogen can explain 87.4% and 7.7% of variation in maize seedlings growth and physiological traits, respectively. These results display that maize seedlings shoot is more susceptible to the impact of PVC-MPs and soil available nitrogen is the primary limiting factor on maize seedlings growth and physiological traits triggered by PVC-MPs. Impacts of PVC-MPs on maize seedlings growth and physiological traits by nitrogen depletion lead to the possible yield and economic loess and potential risks due to the over use of nitrogen fertilizers.
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Compostos de Amônio , Microplásticos , Plântula , Plásticos/toxicidade , Zea mays , Cloreto de Polivinila/toxicidade , Nitratos/toxicidade , Solo , Nitrogênio , Compostos OrgânicosRESUMO
The spike is the organ that contributes the most to lead (Pb) accumulation in wheat grains. However, as an important photosynthetic and transpiration tissue in spike, the role of awn in wheat grain Pb absorption remains unknown. A field experiment was conducted to investigate the influence mechanism of awn on grain Pb accumulation through two comparative treatments: with and without awns (de-awned treatment). The de-awned treatment decreased wheat yield by 4.1 %; however, it significantly lowered the grain Pb accumulation rate at the late filling stage (15 days after anthesis) and led to a 22.8 % decrease in grain Pb concentration from 0.57 to 0.44 mg·kg-1. Moreover, the relative contribution of awn-to-grain Pb accumulation gradually increased with the filling process, finally reaching 26.6 % at maturity. In addition, Pb isotope source analysis indicated that the Pb in the awn and grain mainly originated from atmospheric deposition, and the de-awned treatment decreased the proportion of grain Pb from atmospheric deposition by 8.9 %. Microstructural observations further confirmed that the contribution of awns to grain Pb accumulation mainly originated from their direct absorption of atmospheric Pb. In conclusion, awns play an important role in wheat grain Pb absorption at the late grain-filling stage; planting awnless or short-awn wheat varieties may be the simplest and effective environmental management measure to reduce the health risks of Pb in wheat in regions with serious atmospheric Pb contamination.
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Chumbo , Triticum , Triticum/química , Chumbo/análise , Grão Comestível/química , Poluição Ambiental , FotossínteseRESUMO
The management of heavy metal contaminated soil has received extensive research attention. In this study, a novel immobilization agent (SiO2@Fe3O4@C-COOH) was combined with traditional immobilization agents (TIAs), i.e., CaO, organic matter (OM), and calcium superphosphate (CSP), and used to remediate Pb-contaminated soil. The immobilization effects of Pb in soil was evaluated through pot experiments involving wheat cultivation. The results indicated that SiO2@Fe3O4@C-COOH delivered a higher Pb immobilization efficiency than did TIAs such as CaO, OM, and CSP. The application of SiO2@Fe3O4@C-COOH in combination with TIAs (CaO, OM, and CSP) synergistically enhanced the Pb immobilization efficiency of the soil to 85.10%. Further, joint application in a 54.19% reduction of Pb content in wheat roots, a 65.78% reduction in stems, and a 47.96% in leaves. Thus, the combined application of SiO2@Fe3O4@C-COOH and TIAs significantly reduced the bioavailability of Pb, achieved the purpose of Pb stabilization and soil remediation, and has the potential for wide-spread application in the remediation of Pb-contaminated soils.
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Recuperação e Remediação Ambiental , Nanoestruturas , Poluentes do Solo , Chumbo , Fenômenos Magnéticos , Dióxido de Silício , Solo , Poluentes do Solo/análiseRESUMO
In this study, exposure experiments were conducted to assess the effects of polystyrene nanoparticles (PS) and amine-modified polystyrene nanoparticles (APS) at environmental concentrations (1, 10, and 100 µg L- 1) on two fungal species (Geotrichum candidum and Aspergillus niger), isolated from leaf litter in streams, concerning their growth and metabolic activity. Results showed that PS at 1 and 10 µg L- 1 have hormesis effects on G. candidum growth. Compared with G. candidum, A. niger had higher sensitivity to nanoplastic exposure. Besides, the peroxidase and cellobiohydrolase activities of A. niger were significantly inhibited by nanoplastics (except 1 µg L- 1 PS), which would weaken its metabolic activity in carbon cycling. These results provided a new thought on how the growth and functions of aquatic fungi cope with the stress induced by nanoplastics. Overall, the study provided evidence for the different responses of aquatic fungi to nanoplastics in streams.
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Aspergillus niger , Microplásticos , Poliestirenos/toxicidade , Geotrichum/metabolismoRESUMO
Wheat flag leaf (FL) is one of the primary sources of carbohydrates in grains; however, its role in grain lead (Pb) absorption remains unclear. A field experiment was conducted to assess the relative contribution of the FL to Pb accumulation in wheat grain by two contrasting treatments: without (CK) and with FL removal (FLR) at the grain-filling stage. The Pb concentration in leaves was closely related to leaf strata and decreased from FL to the third leaf. FLR treatment significantly reduced the yield and grain Pb concentration by 2.79% and 11.47%, respectively. The contribution of FL to grain Pb accumulation decreased gradually with the filling process, from 35.08% (at early stage) to 13.94% (at maturity stage). After FLR, the contribution proportion of atmospheric fallout to grain Pb decreased from 69.01% (CK) to 62.43% (FLR). Combined isotope analysis with scanning electron microscopy and energy-dispersive X-ray spectroscopy (SEM-EDS) revealed that the main contribution of FLs to grain Pb originated from Pb fallout in fine atmospheric particles. Therefore, taking measures to reduce the influence of fine atmospheric particles on wheat may be an effective way to control wheat grain Pb contamination.
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Chumbo , Triticum , Grão Comestível , Isótopos , Folhas de PlantaRESUMO
It is challenging to design and prepare difunctional photocatalysts for simultaneous photocatalytic wastewater purification and hydrogen (H2) energy production. In this study, a novel ternary heterostructure pholocatalyst, ZnIn2S4@SiO2@TiO2 (ZIS@SiO2@TiO2) was successfully prepared by simple sol-gel and solvothermal methods. The SiO2 nanospheres were used as a support to prevent the aggregation of TiO2 nanoparticles efficiently. The SiO2@TiO2 nanoparticles were uniformly inserted into the 2D-layered flowerlike ZnIn2S4 to form a ternary heterostructure that can efficiently improve the separation and transportation of photoinduced electron-hole pairs. As expected, the 150%-ZIS@SiO2@TiO2 nanocomposite exhibited an excellent rate of H2 production under simulated sunlight (618.3 µmol g-1 h-1), which was 229 and 3.3 times higher than the binary SiO2@TiO2 nanoparticles and pure ZnIn2S4. Furthermore, the degradation efficiency of methylene blue reached 99.7% during the H2 production process. These findings provided possibilities to couple energy conversion with environmental restoration.
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BACKGROUND: The coronavirus disease 2019 (COVID-19) is an emerging infectious disease that spreads around the world. The lack of effective antiviral drugs and vaccines, along with the relatively high mortality rate and high contagiousness, has raised strong public concerns over COVID-19, especially for people living in the most severely affected areas. This study aimed to clarify the influencing factors for the anxiety level among the Chinese people during the COVID-19 pandemic, with a particular focus on the media exposure to different COVID-19 information. METHODS: A total of 4991 respondents were randomly recruited from a national online panel from February 12th, 2020 to February 14th, 2020, a period when the number of COVID-19 cases surpassed 10,000 in a single day, with the total cases in China reaching up to 90,000. The relationships between media exposure of COVID-19 information, social and geographical proximity to COVID-19, risk perceptions were assessed using hierarchical ordinary least squares regression analysis. RESULTS: The media exposure to COVID-19 information was differently associated with anxiety. Meanwhile, the anxiety level was found to be high in respondents who personally knew someone infected with COVID-19 or those who living in an area with reported cases. Respondents who perceived more risks also reported a higher level of anxiety. CONCLUSIONS: This study highlights the role of media exposure in affecting individuals' anxiety level during the COVID-19 pandemic. Besides, it is recommended that government and health professionals are recommended to adopt effective risk communication strategies to protect citizens' mental health during the pandemic.
Assuntos
Ansiedade/epidemiologia , Informação de Saúde ao Consumidor/estatística & dados numéricos , Infecções por Coronavirus/epidemiologia , Meios de Comunicação de Massa/estatística & dados numéricos , Pandemias , Pneumonia Viral/epidemiologia , Adolescente , Adulto , COVID-19 , China/epidemiologia , Autoavaliação Diagnóstica , Feminino , Humanos , Relações Interpessoais , Masculino , Pessoa de Meia-Idade , Características de Residência/estatística & dados numéricos , Medição de Risco , Adulto JovemRESUMO
Acid rain containing SO42- and NO3- in China has been a public concern for decades. However, a decrease of SO2 has been recorded since the government enacted a series of policies to control its emission. To comprehensively evaluate the consequence of realistic and future acid deposition scenarios, this study explored the effects of mixed acid rain with different molar ratios of SO42- and NO3- (0:1, 1:0, 2:1, 1:1, and 1:2) on stream leaf breakdown through a microcosm experiment. A significant inhibition of leaf breakdown rate was observed when the ratio was 1:2 with reduced microcosm pH, fungal biomass, enzyme activities as well as the frequencies of hub general in the fungal community. In conclusion, the ratio of SO42- and NO3- in acid rain was an important factor that could have a profound impact on leaf breakdown, even on ecosystem structure and functioning of streams.
Assuntos
Chuva Ácida/efeitos adversos , Água Doce/química , Nitratos/toxicidade , Folhas de Planta/metabolismo , Sulfatos/toxicidade , Chuva Ácida/análise , Biodegradação Ambiental/efeitos dos fármacos , Biomassa , China , Ecossistema , Água Doce/microbiologia , Micobioma/efeitos dos fármacos , Nitratos/análise , Sulfatos/análiseRESUMO
A field experiment was conducted to assess the atmospheric deposition effects on lead (Pb) contamination in wheat by two contrasting treatments: wheat exposed or not to atmospheric deposition. Plants were housed in a shed during wheat greening for the non-exposed treatment. The Pb contents of wheat during different growth stages, of soil and of atmospheric deposits were analysed and combined with Pb stable isotope data to quantify the contribution of atmospheric deposition and soil to Pb in wheat tissue. The Pb content in atmospheric deposits was significantly higher than those in soil and wheat tissue, and the Pb content in wheat tissue exposed to atmospheric deposition was significantly higher than the Pb content in non-exposed tissue (pâ¯<â¯0.05). The 206Pb/207Pb of soil was significantly higher than the 206Pb/207Pb of atmospheric deposits (pâ¯<â¯0.05), and soil and atmospheric deposition were the two sources of Pb in wheat tissue. Atmospheric deposition was the main source of wheat tissue Pb in the exposed treatment, and most of the wheat tissue Pb, except for that in the stem, also came from atmospheric deposition in the maturing stage. The proportion of Pb from atmospheric deposition in roots, stems and leaves evidently decreased after the shed was erected, and the contribution of Pb from atmospheric deposition to wheat tissue was significantly higher in the exposed treatment than in the non-exposed treatment (pâ¯<â¯0.05). This contrast test directly confirmed that atmospheric deposition was the main source of Pb in the wheat tissues. Therefore, taking measures to reduce the absorption of Pb by wheat from atmospheric deposition can effectively ensure food safety.
Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Chumbo/análise , Poluentes do Solo/análise , Triticum/química , China , Modelos Teóricos , Raízes de Plantas/química , Estações do Ano , Solo/química , Triticum/crescimento & desenvolvimentoRESUMO
Limited information on the potential toxicity of ionic liquids (ILs) becomes the bottleneck that creates a barrier in their large-scale application. In this work, two quantitative structure-activity relationships (QSAR) models were used to evaluate the toxicity of ILs toward the acetylcholinesterase enzyme using multiple linear regression (MLR) and extreme learning machine (ELM) algorithms. The structures of 57 cations and 21 anions were optimized using quantum chemistry calculations. The electrostatic potential surface area (SEP) and the screening charge density distribution area (Sσ) descriptors were calculated and used for prediction of IL toxicity. Performance and predictive aptitude between MLR and ELM models were analyzed. Highest squared correlation coefficient (R2), and also lowest average absolute relative deviation (AARD%) and root-mean-square error (RMSE) were observed for training set, test set, and total set for the ELM model. These findings validated the superior performance of ELM over the MLR toxicity prediction model.
Assuntos
Acetilcolinesterase/metabolismo , Inibidores da Colinesterase/toxicidade , Líquidos Iônicos/toxicidade , Animais , Inibidores da Colinesterase/química , Humanos , Concentração Inibidora 50 , Líquidos Iônicos/química , Modelos Lineares , Aprendizado de Máquina , Modelos Biológicos , Relação Quantitativa Estrutura-AtividadeRESUMO
In this study, the effects of 4-chlorophenol (4-CP) influent concentrations ranging from 10 to 100 mg L-1 on sludge toxicity, enzymatic activity and microbial community, along with their correlations, were investigated in a sequencing batch bioreactor (SBR), which was defined as the acclimated SBR. Another SBR was set as a control group that did not receive the influent 4-CP. The results showed that the sludge toxicity increased as the influent 4-CP increased, exhibiting a positive correlation with 4-CP loads. The enzymatic activity was stimulated after long-term acclimation with 4-CP and was positively related to the 4-CP loads and sludge toxicity. During the stable operational stages of the acclimated SBR, the microbial diversity first increased and then decreased as the 4-CP loads increased, while the similarity of the microbial community between the acclimated and control SBRs decreased with increasing 4-CP loads. The aim of this study is to provide theoretical support for reducing sludge toxicity in industrial wastewater treatment.
Assuntos
Reatores Biológicos/microbiologia , Clorofenóis/toxicidade , Microbiota/efeitos dos fármacos , Esgotos/microbiologia , Eliminação de Resíduos Líquidos/métodos , Purificação da Água/métodos , Clorofenóis/análise , Esgotos/química , Águas Residuárias/química , Águas Residuárias/microbiologiaRESUMO
In order to trace the source of Pb pollution in wheat, the contribution ratio of soil and atmospheric fallout source was quantified based on stable isotope ratios. Results showed that the average Pb content of soil was significantly lower than that of fallout, and Pb in the fallout had a higher weak acid fraction than soil. Pb in wheat had a distinct distribution in its tissues and the content of Pb in wheat roots was significantly higher than it in shoots. The 206Pb/207Pb ratio of soil was significantly higher than that in atmospheric fallout (p < 0.05). According to a binary mixing model, the 206Pb/207Pb ratio in wheat roots, leaves, and grains reflect 67%, 65%, and 90% of Pb content contributions from fallout, respectively. This results suggest that fallout Pb was absorbed by wheat leaves and transferred to other organs, and it is important to develop effective strategies to control fallout Pb risks.
Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Chumbo/análise , Poluentes do Solo/análise , Triticum/química , China , Isótopos , Folhas de Planta/química , Raízes de Plantas/química , Chuva/química , Estações do Ano , Solo/químicaRESUMO
Hierarchical Ag-SiO2@Fe3O4 magnetic composites were selected for elemental mercury (Hg0) removal from non-ferrous metal smelting flue gas in this study. Results showed that the hierarchical Ag-SiO2@Fe3O4 magnetic composites had favorable Hg0 removal ability at low temperature. Moreover, the adsorption capacity of hierarchical magnetic composite is much larger than that of pure Fe3O4 and SiO2@Fe3O4. The Hg0 removal efficiency reached the highest value as approximately 92% under the reaction temperature of 150°C, while the removal efficiency sharply reduced in the absence of O2. The characterization results indicated that Ag nanoparticles grew on the surface of SiO2@Fe3O4 support. The large surface area of SiO2 supplied efficient reaction room for Hg and Ag atoms. Ag-Hg amalgam is generated on the surface of the composites. In addition, this magnetic material could be easily separated from fly ashes when adopted for treating real flue gas, and the spent materials could be regenerated using a simple thermal-desorption method.
Assuntos
Poluentes Atmosféricos/química , Nanopartículas de Magnetita/química , Mercúrio/química , Nanocompostos/química , Dióxido de Silício/química , Prata/química , Poluição do Ar/prevenção & controle , Cinza de Carvão/química , MetalurgiaRESUMO
Organophosphate esters (OPEs), widely used as flame retardants and plasticizers, are regarded as emerging pollutants. OPEs are prone to concentrate into residual activated sludge, which might cause secondary pollution if not suitably treated. Composting is an economical and effective approach to make sewage sludge stable and harmless. Therefore, it is essential to develop a novel method for analyzing OPEs in sewage sludge compost samples. However, in the composting process, large amounts of amendments are doped into the sludge to adjust the carbon-nitrogen ratio. Amendment has a strong capacity for adsorption and thus induces a decrease of extraction efficiency. This study developed a novel procedure for determining OPEs in compost samples. Accelerated solvent extraction (ASE) and solid phase extraction (SPE) were used for extracting and concentrating the OPEs from sewage sludge compost samples, and then analyzed by UHPLC-MS/MS. Some parameters were optimized in this study, mainly including the extraction solvent type, extraction temperature, static extraction time, extraction cycles, and flush volume. Under the optimal conditions, the proposed method showed good linearity between 0.50 and 100 µg kg-1 with regression coefficients in the range of 0.9984-0.9998. Detection limits were in the range of 0.02-3 µg kg-1 with standard deviations ranging from 2 to 6%. Acceptable recoveries between 56 and 119% for samples spiked at different concentration levels were achieved. In contrast, the recoveries merely ranged from 24 to 58% by using ultrasonic-assisted extraction. Graphical abstract A comparison of recoveries between ultrasonic-assisted extraction (UAS) and accelerated solvent extraction (ASE) for organophosphate esters from sewage sludge compost samples.
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Organophosphate esters, widely used as flame retardants and plasticizers, are regarded as a class of emerging pollutants. In this work, a novel approach was developed for the fabrication of a solid-phase microextraction fiber by using hybrid silica-based materials with immobilized ionic liquids with sol-gel technology, and the prepared solid-phase microextraction fiber was then coupled with gas chromatography and flame photometric detection for the analysis of six organophosphate esters. The high loading of 1-hexadecyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide was confined within the hybrid network. The developed solid-phase microextraction fiber possesses a coating thickness of â¼35 µm with good thermal stability and long lifetime. The parameters affecting the extraction efficiency such as extraction time, temperature, pH, and ionic strength of the sample solution were optimized. Under the optimized conditions, the limits of detection were in the range of 0.04-0.95 µg L-1 , and the precision of the method assessed with repeatability and reproducibility of (RSD%) Ë13 and Ë29%, respectively. The proposed method was successfully applied to determine the six organophosphate esters in three real water samples, with recoveries in the range of 64.8-125.4% at two different spiking concentration levels. As a result, the proposed method demonstrated its potential for application in trace determination of organophosphate esters in actual water samples.
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Organophosphate esters (OPs), widely used as flame retardants and plasticizers, are regarded as a class of emerging pollutants. The effluent of municipal wastewater treatment plants is generally considered to be the main contributor of OP pollution to the surface water. In this study, anoxic-oxic (AO) and University of Capetown (UCT) processes were selected to investigate the removal efficiency of OPs. The results indicated that the UCT process showed better removal efficiency than that of the AO process. For the chlorinated OPs, approximately 12.3% of tri(2-chloroethyl)phosphate and 11.8% of tri(chloropropyl)phosphate can be removed in the UCT process, which was 12% and 7.8% higher than that of the AO process. In contrast, non-chlorinated OPs, including tris(2-butoxyethyal)phosphate, triphenyl phosphate, and tributyl phosphate, were able to be removed in both processes, with the removal rate of 85.1%, 74.9%, and 29.1% in the AO process, and 88.4%, 63.6%, and 25.2% in the UCT process. Furthermore, linear correlation between the removal rate and logKow of OPs (r2 = 0.539) was observed in the AO process, indicating that OPs with high Kow value (e.g. tri(dichloropropyl)phosphate and triphenyl phosphate) are prone to be removed by adsorption on the residual activated sludge.
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Organofosfatos/química , Águas Residuárias/química , Poluentes Químicos da Água/química , Monitoramento Ambiental/métodos , Oxigênio , Esgotos , Eliminação de Resíduos LíquidosRESUMO
A highly sensitive electrochemical DNA biosensor made of polyaniline (PANI) and gold nanoparticles (AuNPs) nanocomposite (AuNPs@PANI) has been used for the detection of trace concentration of Ag(+). In the presence of Ag(+), with the interaction of cytosine-Ag(+)-cytosine (C-Ag(+)-C), cytosine-rich DNA sequence immobilized onto the surface of AuNPs@PANI has a self-hybridization and then forms a duplex-like structure. The whole detection procedure of Ag(+) based on the developed biosensor was evaluated by electrochemical impedance spectroscopy. On semi-logarithmic plots of the log Ag(+) concentration versus peak current, the results show that the prepared biosensor can detect silver ions at a wide linear range of 0.01-100 nM (R = 0.9828) with a detection limit of 10 pM (signal/noise = 3). Moreover, the fabricated sensor exhibits good selectivity and repeatability. The detection of Ag(+) was determined by Ag(+) self-induced conformational change of DNA scaffold that involved only one oligonucleotide, showing its convenience and availability.
Assuntos
DNA de Cadeia Simples/química , Ácidos Nucleicos Imobilizados/química , Eletrodos Seletivos de Íons , Nanopartículas Metálicas/química , Nanocompostos/química , Prata/análise , Poluentes Químicos da Água/análise , Compostos de Anilina/química , Técnicas Biossensoriais , China , Citosina/química , Impedância Elétrica , Indicadores e Reagentes/análise , Limite de Detecção , Nanopartículas Metálicas/ultraestrutura , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Nanocompostos/ultraestrutura , Concentração Osmolar , Reprodutibilidade dos Testes , Propriedades de SuperfícieRESUMO
BACKGROUND: Midwives experience elevated levels of work-related stress. However, there is limited understanding of the patterns of this stress, its sociodemographic and work-related determinants, and its association with sub-health. METHOD: This multi-center cross-sectional study, conducted in 21 hospitals in Zhuhai City, Guangdong Province, China, involved 300 midwives. Work-related stress levels in midwives were evaluated using the Chinese version of the Nursing Stress Scale, while social, physical and mental sub-health status was measured with the Sub-Health Measurement Scale. Utilizing latent profile analysis, the study aimed to categorize midwives into homogeneous profiles based on patterns of work-related stress. RESULTS: Among the 300 midwives examined, three distinct profiles were identified: profile 1 (n=57, 19â¯%), characterized by low work-related stress; profile 2 (n=149, 50â¯%), representing the moderate work-related stress class; and profile 3 (n=94, 31â¯%), indicative of high work-related stress. Midwives in the high work-related stress profile tended to be younger, with lower monthly income, lower professional titles, and a higher likelihood of night shift work (all P<0.01). Significant and noteworthy trends were observed in sociodemographic characteristics (age, monthly income, and professional title) and work-related characteristics (night shift status). After controlling for confounders, the work-related stress profile demonstrated a negative association with social, physical and mental sub-health status. CONCLUSION: This study highlights integrating stress domains and adopting a person-centered approach to examine midwives' work-related stress. Identifying predictors of profile membership and their relationship with sub-health can inform tailored interventions to reduce stress and improve midwives' well-being.
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Tocologia , Enfermeiros Obstétricos , Estresse Ocupacional , Humanos , Estudos Transversais , Feminino , Adulto , Estresse Ocupacional/psicologia , Tocologia/estatística & dados numéricos , China/epidemiologia , Pessoa de Meia-Idade , Enfermeiros Obstétricos/psicologia , Inquéritos e Questionários , Nível de Saúde , Estresse Psicológico , Local de Trabalho/psicologiaRESUMO
Directly capturing CO2 in ambient air and converting it into value-added fuels using photocatalysis is a potentially valuable technology. In this study, Cu-porphyrin (tetrakis-carboxyphenyl porphyrin copper, CuTCPP) was innovatively anchored on the surface of TiO2 (titanium dioxide) nanosheets to form an S-scheme heterojunction. Based on this, a photocatalytic reaction system for stably converting CO2 in ambient air into value-added fuels at the gas-solid interface was constructed without addition of sacrificial agents and alkaline liquids. Under the illumination of visible light and sunlight, the evolution rate of CO is 56 µmol·g-1·h-1 and 73 µmol·g-1·h-1, respectively, with a potential CO2 conversion rate of 35.8 % and 50.4 %. The enhanced of photocatalytic performance is attributed to the introduction of CuTCPP, which provides additional active sites, significantly improves capture capacity of CO2 and the utilization of electrons. Additionally, the formation of S-scheme heterojunction expands the redox range and improves the separation efficiency of photo-generated charges.