Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
Mais filtros

Bases de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Biomed Environ Sci ; 36(6): 490-500, 2023 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-37424242

RESUMO

Objective: The study aimed to estimate the benchmark dose (BMD) of coke oven emissions (COEs) exposure based on mitochondrial damage with the mitochondrial DNA copy number (mtDNAcn) as a biomarker. Methods: A total of 782 subjects were recruited, including 238 controls and 544 exposed workers. The mtDNAcn of peripheral leukocytes was detected through the real-time fluorescence-based quantitative polymerase chain reaction. Three BMD approaches were used to calculate the BMD of COEs exposure based on the mitochondrial damage and its 95% confidence lower limit (BMDL). Results: The mtDNAcn of the exposure group was lower than that of the control group (0.60 ± 0.29 vs. 1.03 ± 0.31; P < 0.001). A dose-response relationship was shown between the mtDNAcn damage and COEs. Using the Benchmark Dose Software, the occupational exposure limits (OELs) for COEs exposure in males was 0.00190 mg/m 3. The OELs for COEs exposure using the BBMD were 0.00170 mg/m 3 for the total population, 0.00158 mg/m 3 for males, and 0.00174 mg/m 3 for females. In possible risk obtained from animal studies (PROAST), the OELs of the total population, males, and females were 0.00184, 0.00178, and 0.00192 mg/m 3, respectively. Conclusion: Based on our conservative estimate, the BMDL of mitochondrial damage caused by COEs is 0.002 mg/m 3. This value will provide a benchmark for determining possible OELs.


Assuntos
Coque , Exposição Ocupacional , Hidrocarbonetos Policíclicos Aromáticos , Masculino , Feminino , Animais , Variações do Número de Cópias de DNA , Benchmarking , Exposição Ocupacional/efeitos adversos , Exposição Ocupacional/análise , DNA Mitocondrial/genética , Dano ao DNA
2.
Environ Res ; 227: 115799, 2023 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-37015300

RESUMO

Veterinary antibiotics (VAs) are emerging contaminants in soils as they may pose high risks to the ecosystem and human health. Identifying VAs accumulation in soils is essential for assessing their potential risks. Therefore, we investigated the distribution of VAs in soils from vegetable fields and evaluated their potential ecological and antimicrobial resistance risks in the Chongqing region of the Three Gorges Reservoir area, China. Results indicated that twenty-six species of VAs, including nine sulfonamides (SAs), seven quinolones (QNs), four tetracyclines (TCs), four macrolides (MLs), and two other species of VAs were detected in soils, with their accumulative levels ranging from 1.4 to 3145.7 µg kg-1. TCs and QNs were the dominant VAs species in soils with high detection frequencies (100% TCs and 80.6% for QNs) and accumulative concentration (up to 1195 µg kg-1 for TCs and up to 485 µg kg-1 for QNs). Risk assessment indices showed that VAs (specifically SAs, TCs, and QNs) in most vegetable soils would pose a medium to high risk to the ecosystem and antimicrobial resistance. Mixture of VAs posed a higher risk to soil organisms, antimicrobial resistance, and plants than to aquatic organisms. Modeling analysis indicated that socioeconomic conditions, farmers' education levels, agricultural practices, and soil properties were the main factors governing VAs accumulation and environmental risks. Farmers with a high educational level owned large-scale farms and were more willing to use organic fertilizers for vegetable production, which eventually led to high VAs accumulation in vegetable soil. These findings would provide a reference for sustainable agricultural and environmental production under the current scenario of chemical fertilizer substitution by organic products and green agricultural development.


Assuntos
Quinolonas , Poluentes do Solo , Humanos , Antibacterianos/análise , Solo/química , Verduras/química , Ecossistema , Poluentes do Solo/análise , Monitoramento Ambiental/métodos , Tetraciclinas/análise , Sulfanilamida/análise , China , Medição de Risco , Fertilizantes/análise
3.
Huan Jing Ke Xue ; 43(11): 5244-5252, 2022 Nov 08.
Artigo em Chinês | MEDLINE | ID: mdl-36437096

RESUMO

The accumulation of antibiotics in farmland and its ecological risk have become a research hotspot at home and abroad. The objective of this study was to investigate the occurrence and accumulation of antibiotics and their potential environmental and ecological risks in vegetable fields in Kaizhou district of Chongqing country. The occurrence characteristics of antibiotics including tetracyclines, sulfonamides, quinolones, macrolides, and chloramphenicols were detected using experimental analysis. The results showed that there was an accumulation of antibiotics in the vegetable soil, and 18 antibiotics in five categories were detected (0-42.88 µg·kg-1), mainly for tetracyclines and quinolones. The detection rate of quinolone antibiotics was the highest (15.38%-100%), especially for norfloxacin and ofloxacin (100%), whereas the tetracyclines presented the highest concentration (0-42.88 µg·kg-1). The amount of total antibiotics in the vegetable soil was 1.64-233.11 µg·kg-1, whereas different vegetable soils showed the following trend:water spinach soil (89.73 µg·kg-1)>cabbage soil (32.53 µg·kg-1)>pepper soil (32.16 µg·kg-1)>tomato soil (32.13 µg·kg-1)>cucumber soil (26.46 µg·kg-1)>grassland (7.32 µg·kg-1). The correlation results showed that there was a significantly positive correlation between total antibiotic residues and organic fertilizer application (P<0.05) but a significantly negative correlation with soil pH (P<0.05). Quinolones and sulfonamides were negatively correlated with soil water content (P<0.05), whereas quinolones positively correlated with soil available phosphorus and organic matter content (P<0.05). The potential eco-environmental risk assessment results showed that tetracyclines and quinolones in vegetable soil in Kaizhou district had certain ecological risks, of which 62%-92% and 62%-100% of soil samples with quinolones had potential toxicity to soil animals and microorganisms.


Assuntos
Quinolonas , Poluentes do Solo , Animais , Verduras , Antibacterianos/análise , Poluentes do Solo/análise , Solo/química , Tetraciclinas/análise , Quinolonas/análise , Medição de Risco , Sulfonamidas , Sulfanilamida
4.
J Hazard Mater ; 435: 128987, 2022 08 05.
Artigo em Inglês | MEDLINE | ID: mdl-35487003

RESUMO

Soil contamination by pesticide residues has become an increasing concern of ecological protection. However, the soil environmental carrying capacity (SECC) of pesticide residues in agricultural ecosystems was limited studied. Based on the concept of ecological risk assessment, a modified system on the environment carrying capacity was proposed for estimate SECC of pesticide residues in agricultural soils. Subsequently, the assessment on ecological risk and SECC of soil pesticide residues in vegetable ecosystem were performed in the Three Gorges Reservoir Area (TGRA). In 201 topsoil samples, 62.1% of the pesticide compounds were detected over limit of quantitation, and exhibit a high proportion of multiple pesticide contamination. Pyrethroid insecticides and herbicide glyphosate showed most frequent occurrence and high levels. The SECC of the TGRA varies with the limit standard, annual cumulative amount and risk quotient of each pesticide contaminant in soils. Except that fenpropathrin has exceeded SECC, chlorfenapyr, ß-cyfluthrin and glyphosate posed the greatest threat to SECC in the next 50 years. Additionally, ecological risks by pesticide residues in vegetable ecosystem can be affected by various planting activities. These results will contribute to guide the rational application of pesticides and control soil environmental risks, thereby achieving the agricultural green development in the TGRA.


Assuntos
Resíduos de Praguicidas , Praguicidas , Poluentes do Solo , Conservação dos Recursos Naturais , Ecossistema , Monitoramento Ambiental , Resíduos de Praguicidas/análise , Praguicidas/análise , Medição de Risco , Solo/química , Poluentes do Solo/análise , Verduras
5.
IEEE Access ; 9: 29736-29745, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33747683

RESUMO

Photoplethysmography (PPG) is a noninvasive way to monitor various aspects of the circulatory system, and is becoming more and more widespread in biomedical processing. Recently, deep learning methods for analyzing PPG have also become prevalent, achieving state of the art results on heart rate estimation, atrial fibrillation detection, and motion artifact identification. Consequently, a need for interpretable deep learning has arisen within the field of biomedical signal processing. In this paper, we pioneer novel explanatory metrics which leverage domain-expert knowledge to validate a deep learning model. We visualize model attention over a whole testset using saliency methods and compare it to human expert annotations. Congruence, our first metric, measures the proportion of model attention within expert-annotated regions. Our second metric, Annotation Classification, measures how much of the expert annotations our deep learning model pays attention to. Finally, we apply our metrics to compare between a signal based model and an image based model for PPG signal quality classification. Both models are deep convolutional networks based on the ResNet architectures. We show that our signal-based one dimensional model acts in a more explainable manner than our image based model; on average 50.78% of the one dimensional model's attention are within expert annotations, whereas 36.03% of the two dimensional model's attention are within expert annotations. Similarly, when thresholding the one dimensional model attention, one can more accurately predict if each pixel of the PPG is annotated as artifactual by an expert. Through this testcase, we demonstrate how our metrics can provide a quantitative and dataset-wide analysis of how explainable the model is.

6.
Medicine (Baltimore) ; 99(44): e22862, 2020 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-33126330

RESUMO

The aim of this study was to assess the levels of self-perceived burden (SPB) and self-management behavior in elderly stroke survivors during the first 3 months after acute stroke, and to explore the correlation between them.A total of 203 consecutive hospitalized elderly patients diagnosed with stroke were recruited. Self-perceived Burden Scale and Stroke Self-management Scale in 1 month (T1) and 3 months (T2) post-stroke were assessed and compared.The score of SPB in elderly stroke survivors was 28.96 ±â€Š5.50 and 27.25 ±â€Š6.17 at T1 and T2, respectively. Stroke self-management scale scored 165.93 ±â€Š9.82 at T1 and 167.29 ±â€Š10.60 at T2. In the first 3 months post-stroke, the physical burden was dominant (T1 14.73 ±â€Š3.07, T2 14.40 ±â€Š3.13), and the behavior of stroke symptoms and signs monitoring (T1 27.58 ±â€Š6.56, T2 28.64 ±â€Š6.43) and rehabilitation exercise management (T1 21.40 ±â€Š3.28, T2 20.74 ±â€Š3.15) was the worst. SPB was negatively correlated with self-management behavior (T1 r = -.202, T2 r = -.511).Elderly stroke survivors experienced a medium level of SPB and self-management behavior in the first 3 months post-stroke. There is a positive relationship between reduced SPB and improved self-management behavior. Addressing the characteristics and correlations as well as development of targeted interventions for SPB decreasing is beneficial to improving self-management behavior for elderly survivors.


Assuntos
Efeitos Psicossociais da Doença , Autoimagem , Autogestão/psicologia , Reabilitação do Acidente Vascular Cerebral/psicologia , Idoso , Feminino , Humanos , Estudos Longitudinais , Masculino , Pessoa de Meia-Idade , Psicometria/instrumentação , Psicometria/métodos , Autogestão/métodos , Autogestão/estatística & dados numéricos , Acidente Vascular Cerebral/psicologia , Acidente Vascular Cerebral/terapia , Reabilitação do Acidente Vascular Cerebral/métodos , Reabilitação do Acidente Vascular Cerebral/estatística & dados numéricos , Sobreviventes/psicologia , Sobreviventes/estatística & dados numéricos
7.
IEEE J Biomed Health Inform ; 24(3): 649-657, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-30951482

RESUMO

Early detection of Atrial Fibrillation (AFib) is crucial to prevent stroke recurrence. New tools for monitoring cardiac rhythm are important for risk stratification and stroke prevention. As many of new approaches to long-term AFib detection are now based on photoplethysmogram (PPG) recordings from wearable devices, ensuring high PPG signal-to-noise ratios is a fundamental requirement for a robust detection of AFib episodes. Traditionally, signal quality assessment is often based on the evaluation of similarity between pulses to derive signal quality indices. There are limitations to using this approach for accurate assessment of PPG quality in the presence of arrhythmia, as in the case of AFib, mainly due to substantial changes in pulse morphology. In this paper, we first tested the performance of algorithms selected from a body of studies on PPG quality assessment using a dataset of PPG recordings from patients with AFib. We then propose machine learning approaches for PPG quality assessment in 30-s segments of PPG recording from 13 stroke patients admitted to the University of California San Francisco (UCSF) neuro intensive care unit and another dataset of 3764 patients from one of the five UCSF general intensive care units. We used data acquired from two systems, fingertip PPG (fPPG) from a bedside monitor system, and radial PPG (rPPG) measured using a wearable commercial wristband. We compared various supervised machine learning techniques including k-nearest neighbors, decisions trees, and a two-class support vector machine (SVM). SVM provided the best performance. fPPG signals were used to build the model and achieved 0.9477 accuracy when tested on the data from the fPPG exclusive to the test set, and 0.9589 accuracy when tested on the rPPG data.


Assuntos
Fotopletismografia/métodos , Fotopletismografia/normas , Processamento de Sinais Assistido por Computador , Aprendizado de Máquina Supervisionado , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Fibrilação Atrial/diagnóstico , Humanos , Pessoa de Meia-Idade , Oximetria/instrumentação , Acidente Vascular Cerebral , Máquina de Vetores de Suporte , Dispositivos Eletrônicos Vestíveis , Adulto Jovem
8.
Environ Pollut ; 248: 349-357, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30818114

RESUMO

Contamination of agricultural soil by heavy metals has become a global issue concerning food security and human health risk. In this study, a soil investigation was conducted to evaluate metals accumulation, potential ecological and health risks as well as to identify sources of metals in paddy soils in Hanzhong City, which is located in a sedimentary basin. Ninety-two (92) surface soil samples (bulk soil) and their corresponding rice samples, 21 irrigation water samples, and 18 fertilizer samples were collected from two typical counties and quantified for the heavy metals (i.e., As, Cd, Cu, Hg, Pb, and Zn) concentrations. The results showed that As, Cd, and Zn were the main contaminants in soils in the studied area. Additionally, elevated Hg content in soils might also pose risks to the local ecosystem. Cadmium and As demonstrated high mobility, and their average contents in rice grains were slightly higher than the permissible threshold (0.20 mg kg-1). Moreover, Pb, As, and Cd intake via rice consumption might result in potential risks to local residents. Metal distribution revealed that pollution in the studied area is non-homogeneous, and agricultural activities (As, Cu, and Cd), transportation emission (Cu and Pb), coal combustion (Hg and As), and smelting activities (Zn, Pb, and Cu) were ascertained as the potential sources based on the Positive matrix factorization (PMF) analysis results.


Assuntos
Monitoramento Ambiental , Metais Pesados/análise , Poluentes do Solo/análise , Agricultura , Cádmio/análise , China , Ecologia , Ecossistema , Poluição Ambiental/análise , Humanos , Oryza , Medição de Risco , Solo/química
9.
Bioresour Technol ; 274: 73-82, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30500766

RESUMO

Symphytum officinale L., as a hyperaccumulator, was pyrolyzed into biochar at 350, 550, and 750 °C, respectively. PTEs could be enriched in biochars except Cd volatilized greatly at 750 °C. In order to evaluate the environmental acceptability of biochars, a series of sequential and single extractions and biochar oxidation procedures were performed for simulating different environmental conditions. There was a sharp decline in PTEs release under various conditions when the temperature above 550 °C, indicating PTEs might transform into more stable forms at higher temperature. Thus, increasing the pyrolysis temperature is helpful for reducing biochar phytotoxicity, suppressing biochar leaching and improving biochar environmental safety. Moreover, the economic feasibility analysis of the biochar confirmed the practicability of it. Findings from this work illustrated that biochars pyrolyzed from Symphytum officinale L. at the temperature higher than 550 °C might be environmental acceptable, which is beneficial for biochar application.


Assuntos
Biodegradação Ambiental , Carvão Vegetal/metabolismo , Confrei/metabolismo , Temperatura Alta
10.
Med Phys ; 45(5): 2289-2298, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29578579

RESUMO

PURPOSE: The purpose of this work was to explore two novel operation modalities of the rotating gamma systems (RGS) that could expand its clinical application to lesions in close proximity to critical organs at risk (OAR). METHODS: The approach taken in this study consists of two components. First, a Geant4-based Monte Carlo (MC) simulation toolkit is used to model the dosimetric properties of the RGS Vertex 360™ for the normal, intensity modulated radiosurgery (IMRS), and speed modulated radiosurgery (SMRS) operation modalities. Second, the RGS Vertex 360™ at the Rotating Gamma Institute in Debrecen, Hungary is used to collect experimental data for the normal and IMRS operation modes. An ion chamber is used to record measurements of the absolute dose. The dose profiles are measured using Gafchromic EBT3 films positioned within a spherical water equivalent phantom. RESULTS: A strong dosimetric agreement between the measured and simulated dose profiles and penumbra was found for both the normal and IMRS operation modes for all collimator sizes (4, 8, 14, and 18 mm diameter). The simulated falloff and maximum dose regions agree better with the experimental results for the 4 and 8 mm diameter collimators. Although the falloff regions align well in the 14 and 18 mm collimators, the maximum dose regions have a larger difference. For the IMRS operation mode, the simulated and experimental dose distributions are ellipsoidal, where the short axis aligns with the blocked angles. Similarly, the simulated dose distributions for the SMRS operation mode also adopt an ellipsoidal shape, where the short axis aligns with the angles where the orbital speed is highest. For both modalities, the dose distribution is highly constrained with a sharper penumbra along the short axes. CONCLUSIONS: Dose modulation of the RGS can be achieved with the IMRS and SMRS modes. By providing a highly constrained dose distribution with a sharp penumbra, both modes could be clinically applicable for the treatment of lesions in close proximity to critical OARs.


Assuntos
Radiocirurgia/instrumentação , Rotação , Método de Monte Carlo , Órgãos em Risco/efeitos da radiação , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Fatores de Tempo
11.
Appl Environ Microbiol ; 84(8)2018 04 15.
Artigo em Inglês | MEDLINE | ID: mdl-29427423

RESUMO

Streptococcus suis, a global zoonosis of pigs, shows regional differences in the prevalence of human-associated disease for Asian and non-Asian countries. The isolation rates and diversities of S. suis on tonsils of healthy slaughter pigs in China and the United Kingdom were studied for effects of geography, temperature, pig age, and farm type. Isolates underwent analysis of molecular serotype and multilocus sequence type and virulence-associated genotyping. Although we found no significant difference in positive isolation rates between Chinese and UK farms, the prevalences of serotypes previously associated with human disease were significantly greater in the Chinese collection (P = 0.003). A significant effect of temperature was found on the positive isolation rate of the Chinese samples and the prevalence of human disease-associated serotypes in the UK S. suis population (China, P = 0.004; United Kingdom, P = 0.024) and on the prevalence of isolates carrying key virulence genes in China (P = 0.044). Finally, we found marked diversity among S. suis isolates, with statistically significant temperature effects on detection of multiple strain types within individual pigs. This study highlighted the high carriage prevalence and diversity of S. suis among clinically healthy pig herds of China and the United Kingdom. The significant effect of temperature on prevalence of isolation, human disease-associated serotypes, and diversity carried by individual pigs may shed new light on geographic variations in human S. suis-associated disease.IMPORTANCEStreptococcus suis is a global zoonotic pathogen and also a normal colonizer mainly carried on the tonsil of pigs. Thus, it is important to study the effect of environmental and management-associated factors on the S. suis populations in clinically healthy pigs. In this research, we investigated the similarities and differences between the S. suis populations obtained from different pig ages, seasons, and farm management systems and discovered the relationship between high climatic temperature and the prevalence of S. suis.


Assuntos
Criação de Animais Domésticos/métodos , Variação Genética , Infecções Estreptocócicas/veterinária , Streptococcus suis/fisiologia , Doenças dos Suínos/epidemiologia , Fatores Etários , Animais , China/epidemiologia , Genoma Bacteriano , Estudos Longitudinais , Prevalência , Infecções Estreptocócicas/epidemiologia , Infecções Estreptocócicas/microbiologia , Streptococcus suis/genética , Suínos , Doenças dos Suínos/microbiologia , Temperatura , Reino Unido/epidemiologia
12.
PLoS Biol ; 15(8): e2002176, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28763438

RESUMO

Enhancing brown fat activity and promoting white fat browning are attractive therapeutic strategies for treating obesity and associated metabolic disorders. To provide a comprehensive picture of the gene regulatory network in these processes, we conducted a series of transcriptome studies by RNA sequencing (RNA-seq) and quantified the mRNA and long noncoding RNA (lncRNA) changes during white fat browning (chronic cold exposure, beta-adrenergic agonist treatment, and intense exercise) and brown fat activation or inactivation (acute cold exposure or thermoneutrality, respectively). mRNA-lncRNA coexpression networks revealed dynamically regulated lncRNAs to be largely embedded in nutrient and energy metabolism pathways. We identified a brown adipose tissue-enriched lncRNA, lncBATE10, that was governed by the cAMP-cAMP response element-binding protein (Creb) axis and required for a full brown fat differentiation and white fat browning program. Mechanistically, lncBATE10 can decoy Celf1 from Pgc1α, thereby protecting Pgc1α mRNA from repression by Celf1. Together, these studies provide a comprehensive data framework to interrogate the transcriptomic changes accompanying energy homeostasis transition in adipose tissue.


Assuntos
Tecido Adiposo/metabolismo , Proteínas CELF1/metabolismo , Metabolismo Energético , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , RNA Longo não Codificante/metabolismo , Animais , Diferenciação Celular , AMP Cíclico/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Regulação da Expressão Gênica , Células HEK293 , Humanos , Masculino , Camundongos Endogâmicos C57BL , Cultura Primária de Células , Transdução de Sinais , Transcriptoma
13.
Huan Jing Ke Xue ; 38(9): 3888-3896, 2017 Sep 08.
Artigo em Chinês | MEDLINE | ID: mdl-29965272

RESUMO

There has been a growing interest in soil replacement and in-situ stabilization techniques in recent years. Many techniques in the remediation of contaminated soils have been proven to be effective methods. In this study, lime and calcium phosphate were added to immobilize the heavy metals in contaminated soils. The long-term application potential of these techniques were evaluated by taking the demonstration project of the soil remediation in Tongguan of Shaanxi as the case study.The status of heavy metal contamination in the study area resulted from artisanal gold mining was discussed. The strategies of remediation and the evaluation of the remediation results including the safety of agricultural practices were also studied. The results showed that soil was seriously contaminated in the study area with Cd, Pb, and Hg, and the residue mining waste was the main source. The potential ecological risk index ranged from 668 to 10969, suggesting that all the samples posed a very strong ecological hazard. Based on the pollution status, the soil replacement method and stabilization method were applied. Acceptable remediation results were obtained with lower total metal content (except Cd) and decreased heavy metal availability. However, the metal content of agricultural products was higher than the permissible value according to GB 2762-2012, which means that agricultural practices pose risks on remediated soils. Soil replacement and stabilization would be practical techniques for heavy metal polluted soil remediation. However, a consecutive investigation should be conducted for the assurance of food safety.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA