RESUMO
Pyrethroids (PYs) are widely applied pesticides whose residues pose potential health risks. This review describes current knowledge on PY chemical properties, usage patterns, environmental and food contamination, and human exposure models. It evaluates life cycle assessment (LCA), chemical alternatives assessment (CAA), and high-throughput screening (HTS) as tools for pesticide policy. Despite efforts to mitigate PY presence, their pervasive residues in the environment and food persist. And the highest concentrations ranged from 54,360 to 80,500â¯ng/L in water samples from agricultural fields. Food processing techniques variably reduce PY levels, yet no method guarantees complete elimination. This review provides insights into the fates and exposure pathways of PY residues in agriculture and food, and highlights the necessity for improved PY management and alternative practices to safeguard health and environment.
Assuntos
Contaminação de Alimentos , Resíduos de Praguicidas , Piretrinas , Humanos , Agricultura , Exposição Ambiental/análise , Monitoramento Ambiental , Contaminação de Alimentos/análise , Resíduos de Praguicidas/análise , Piretrinas/análise , Piretrinas/toxicidade , Medição de Risco , Poluentes Químicos da Água/análiseRESUMO
Beta-cypermethrin (ß-CYP) consists of four chiral isomers, acting as an environmental estrogen and causing reproductive toxicity, neurotoxicity, and dysfunctions in multiple organ systems. This study investigated the toxic effects of ß-CYP, its isomers, metabolite 3-phenoxybenzoic acid (3-PBA), and 17ß-estradiol (E2) on HTR-8/SVneo cells. We focused on the toxic mechanisms of ß-CYP and its specific isomers. Our results showed that ß-CYP and its isomers inhibit HTR-8/SVneo cell proliferation similarly to E2, with 100 µM 1S-trans-αR displaying significant toxicity after 48 h. Notably, 1S-trans-αR, 1R-trans-αS, and ß-CYP were more potent in inducing apoptosis and cell cycle arrest than 1R-cis-αS and 1S-cis-αR at 48 h. AO/EB staining and flow cytometry indicated dose-dependent apoptosis in HTR-8/SVneo cells, particularly at 100 µM 1R-trans-αS. Scratch assays revealed that ß-CYP and its isomers variably reduced cell migration. Receptor inhibition assays demonstrated that post-ICI 182780 treatment, which inhibits estrogen receptor α (ERα) or estrogen receptor ß (ERß), ß-CYP, its isomers, and E2 reduced HTR-8/SVneo cell viability, whereas milrinone, a phosphodiesterase 3 A (PDE3A) inhibitor, increased viability. Molecular docking studies indicated a higher affinity of ß-CYP, its isomers, and E2 for PDE3A than for ERα or ERß. Consequently, ß-CYP, its isomers, and E2 consistently led to decreased cell viability. Transcriptomics and RT-qPCR analyses showed differential expression in treated cells: up-regulation of Il24 and Ptgs2, and down-regulation of Myo7a and Pdgfrb, suggesting the PI3K-AKT signaling pathway as a potential route for toxicity. This study aims to provide a comprehensive evaluation of the cytotoxicity of chiral pesticides and their mechanisms.
Assuntos
Apoptose , Piretrinas , Humanos , Piretrinas/toxicidade , Piretrinas/farmacologia , Apoptose/efeitos dos fármacos , Linhagem Celular , Simulação de Acoplamento Molecular , Estradiol/farmacologia , Proliferação de Células/efeitos dos fármacos , Inseticidas/toxicidade , Inseticidas/farmacologia , Inseticidas/química , Isomerismo , Movimento Celular/efeitos dos fármacos , Benzoatos/farmacologia , Benzoatos/química , Estereoisomerismo , Sobrevivência Celular/efeitos dos fármacos , Receptor alfa de Estrogênio/metabolismo , Pontos de Checagem do Ciclo Celular/efeitos dos fármacosRESUMO
Microbial degradation of pesticide residues has the potential to reduce their hazards to human and environmental health. However, in some cases, degradation can activate pesticides, making them more toxic to microbes. Here we report on the ß-cypermethrin (ß-CY) toxicity to Bacillus cereus GW-01, a recently described ß-CY degrader, and effects of antioxidants on ß-CY degradation. GW-01 exposed to ß-CY negatively affected the growth rate. The highest maximum specific growth rate (µm) appeared at 25 mg/L ß-CY. ß-CY induced the oxidative stress in GW-01. The activities of superoxide dismutase (SOD), catalyse (CAT), and glutathione-S-transferase (GST) were significantly higher than that in control (p < 0.01); but they are decreased as growth phase pronged, which is contrary to the ß-CY degradation by GW-01 cells obtaining from various growth phase. Ascorbic acid (Vc), tea polyphenols (TP), and adenosine monophosphate (AMP) improved the degradation through changing the physiological property of GW-01. TP and AMP prompted the expression of gene encoding ß-CY degradation in GW-01, while Vc does the opposite. Biofilm formation was significantly inhibited by ß-CY, while was significantly enhanced by certain concentrations of TP and AMP (p < 0.05); while cell surface hydrophobicity (CSH) was negatively associated with ß-CY concentrations from 25 to 100 mg/L, and these 4 antioxidants all boosted the CSH. Cells grown with ß-CY had lower levels of saturated fatty acids but increased levels of some unsaturated and branched fatty acids, and these antioxidants alleviated the FA composition changes and gene expression related with FA metabolism. We also mined transcriptome analyses at lag, logarithmic, and stationary phases, and found that ß-CY induced oxidative stress. The objective of this study was to elaborate characteristics in relation to the microbial resistance of pesticide poisoning and the efficiency of pesticide degradation, and to provide a promising method for improving pesticide degradation by microbes.
Assuntos
Antioxidantes , Praguicidas , Humanos , Antioxidantes/farmacologia , Antioxidantes/metabolismo , Bacillus cereus/metabolismo , Disponibilidade Biológica , Estresse Oxidativo , Praguicidas/toxicidade , Ácidos Graxos , Monofosfato de Adenosina/metabolismo , Monofosfato de Adenosina/farmacologiaRESUMO
Mexican tea (Dysphania ambrosioides (L.) Mosyakin & Clemants) is rich in phenolic acids and flavonoids and could be a potential medicinal herb that can be used for prevention of human hepatocellular carcinoma. The objective of this study was to elaborate the possible mechanism for the prevention or treatment of hepatocellular carcinoma using Mexican tea, and to provide new avenues for the utilization of the invasive plant. In this study, the D. ambrosioides seed extracts (CSE) were analyzed by gas chromatography-mass spectrometry, and the effects of CSE on proliferation, migration, invasion, and gene expression of SMMC-7721 cells were investigated. Eight compounds were identified in CSE, and the compound with the highest content was ascaridole (25.82 %). The proliferation was significantly inhibited by CSE (p<0.05), and IC50 values were 0.587â g/L, 0.360â g/L, and 0.361â g/L at 24â h, 36â h, and 48â h, respectively. Migration and invasion were significantly inhibited (p<0.05). The network pharmacology and transcriptome analysis indicated that 2-hydroxy-2,6,6-trimethylbicyclo[3.1.1]heptan-3-one, cis-11-eicosenoic acid and 2-ethylcyclohexanone might be the active compounds. Transcriptome analysis indicated that the Wnt signaling pathway, which is related to migration and invasion, was significantly altered; this was verified by western blot assay. The expression of wnt11, lef1 and mmp7 genes in SMMC-7721 cells was significantly down-regulated (p<0.05), while gsk-3ß was significantly up-regulated (p<0.05). These results indicate that CSE inhibits the invasion and migration of SMMC-7721 cells in hepatocellular carcinoma through the Wnt signaling pathway.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Extratos Vegetais , Humanos , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Glicogênio Sintase Quinase 3 beta , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/metabolismo , Extratos Vegetais/química , Extratos Vegetais/farmacologia , CháRESUMO
Erigeron Canadensis L. (E.â canadensis) is a widely distributed invasive weed species in China. Potentially anti-cancer qualities may exist in its essential oils (EOs). The purpose of this study was to analyze the components of the EOs of E.â canadensis and their effects on the normal liver cell lines L02 and the human cervical cancer cell lines HeLa. The EOs from the upper region of E.â canadensis were prepared, its components were identified by GC/MS. Cell viability, cell morphology observation, AO/EB dual fluorescence staining assay, flow cytometry, mitochondrial membrane potential, western blot, caspase inhibitor test, and oxidative stress tests were used to investigate the impact of the EOs on HeLa cells. Network pharmacological analysis was employed to study the potential mechanism of the EOs in the treatment of cervical cancer. According to the findings, the EOs had 21 chemical components, of which limonene made up 65.68 %. After being exposed to the EOs, the cell viability of HeLa and L02 dramatically declined. The inhibition of EOs was more effective than that of limonene when used in an amount equivalent to that in the EOs. L02 cells were less susceptible to the cytotoxicity of EOs than HeLa cells were. Furthermore, EOs altered the cell cycle in HeLa cells and caused oxidative stress and apoptosis. Compared with the control group, the reactive oxygen species (ROS) levels increased in HeLa cells at first and then decreased, total superoxide dismutase (SOD) and catalase (CAT) activities in HeLa cells significantly decreased. G1 phase cells decreased whereas G2/M phase cells increased. The rate of apoptosis rose. Reduced mitochondrial membrane potential and Caspase-3, -9, and -12 protein expression were both observed. Nerolidol, dextroparaffinone, and α-pinene were shown to be the primary components for the suppression of HeLa cells, according to the results of the prediction of pharmacologic targets. In conclusion, findings of this study indicated the EOs may have the potential to curb the growth of cervical cancer cells. Further research is needed to explore the inâ vivo effect of EOs.
Assuntos
Antineoplásicos , Erigeron , Óleos Voláteis , Neoplasias do Colo do Útero , Antineoplásicos/farmacologia , Apoptose , Caspase 3 , Catalase , Erigeron/metabolismo , Feminino , Células HeLa , Humanos , Limoneno/farmacologia , Limoneno/uso terapêutico , Óleos Voláteis/farmacologia , Óleos Voláteis/uso terapêutico , Espécies Reativas de Oxigênio/metabolismo , Superóxido Dismutase , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/metabolismoRESUMO
Airborne particular matter (PM) pollution is an increasing global issue and alternative sources of filter fibers are now an area of significant focus. Compared with relatively mature hazardous gas treatments, state of the art high-efficiency PM filters still lack thermal decomposition ability for organic PM pollutants, such as soot from coal-fired power plants and waste-combustion incinerators, resulting in frequent replacement, high cost, and second-hand pollution. In this manuscript, we propose a bottom-up synthesis method to make the first all-thermal-catalyst air filter (ATCAF). Self-assembled from â¼50 nm diameter TiO2 fibers, ATCAF could not only capture the combustion-generated PM pollutants with >99.999% efficiency but also catalyze the complete decomposition of the as-captured hydrocarbon pollutants at high temperature. It has the potential of in situ eliminating the PM pollutants from burning of hydrocarbon materials leveraging the burning heat.
Assuntos
Poluentes Atmosféricos , Poluentes Atmosféricos/análise , Catálise , Temperatura Alta , Centrais ElétricasRESUMO
This study aims to systematically evaluate the efficacy and safety of Shuxuetong Injection in the treatment of stroke in progressive. Randomized controlled trials of Shuxuetong Injection in the treatment of stroke in progressive were searched from CNKI, Wanfang, VIP, CMB, PubMed and EMbase. After strict literature screening, data extraction and quality evaluation, a total of 22 articles were included for analysis by RevMan 5.3. The Meta-analysis showed that Shuxuetong Injection combined with conventional treatment was superior to the conventional treatment alone in the major outcome indicators including effective rate(RR=1.27, 95%CI[1.20, 1.33], Z=9.18, P<0.000 01), deterioration rate(RR=0.38, 95%CI[0.22, 0.68], Z=3.31, P=0.000 9), NIHSS scores(MD=-3.89, 95%CI[-4.34,-3.43], Z=16.83, P<0.000 01), CSS scores(MD=-5.59, 95%CI[-6.42,-4.76], Z=13.20, P<0.000 01) and activity of daily living scores(MD=12.02, 95%CI[10.31, 13.72], Z=13.83, P<0.000 01), mortality during treatment was not increased(RR=0.40, 95%CI[0.13, 1.26], Z=1.56, P=0.12). Moreover, Shuxuetong Injection combined with conventional treatment further reduced the secondary outcome indicators including fibrinogen(MD=-0.35, 95%CI[-0.58,-0.13], Z=3.09, P=0.002), triglyceride(MD=-0.38, 95%CI[-0.67,-0.10], Z=2.65, P=0.008), low density lipoprotein cholesterol(MD=-0.72, 95%CI[-0.83,-0.61], Z=12.64, P<0.000 01), serum hypersensitive C-reactive protein(MD=-4.41, 95%CI[-6.96,-1.86], Z=3.38, P=0.000 7), and interleukin-6(MD=-5.43, 95%CI[-6.91,-3.96], Z=7.22, P<0.000 01). GRADE evaluation results showed that the major outcome indicators had low quality of evidence. Shuxuetong Injection in the treatment of stroke in progressive can improve the clinical effective rate, reduce the deterioration rate, improve the neurological function and activity of daily living, down-regulate the levels of fibrinogen, triglyceride, low density lipoprotein cholesterol and alleviate the inflammatory response. Although most studies have reported no adverse reactions, there are selective reports. The safety of Shuxuetong Injection needs to be further verified by more high-quality randomized controlled trial.
Assuntos
Medicamentos de Ervas Chinesas , Acidente Vascular Cerebral , Medicamentos de Ervas Chinesas/uso terapêutico , Humanos , Injeções , Acidente Vascular Cerebral/tratamento farmacológico , Resultado do TratamentoRESUMO
Methylmercury (MeHg) exposure during pregnancy can lead to adverse outcomes, including miscarriage and intrauterine growth retardation. In this study, MeHg cytotoxicity and its mechanisms in HTR-8/SVneo cells were investigated. MeHg inhibited HTR-8/SVneo cell viability and severely disrupted the cellular submicrostructure, showing a time-dose effect relationship. After MeHg treatment, the reactive oxygen species levels, malondialdehyde content, and superoxide dismutase (SOD) and catalase activities in the HTR-8/SVneo cells increased significantly with increased MeHg concentration (P<0.05). Similarly, MeHg also induced HTR-8/SVneo cell apoptosis in a dose-dependent manner. The proportion of cells in G1 phase decreased with increasing MeHg concentration, while that in the S and G2/M phases gradually increased. Moreover, cell migration and invasion capacities gradually decreased with increasing MeHg concentration, showing a significant difference between the MeHg-treated and control groups. Genes related to oxidative stress (HSPA6, HSPA1A, Nrf2, SOD1, HO-1, NQO1, OSGIN1, and gPX1), cell cycle (P21 and CDC25A), apoptosis (CYCS and AIFM2), and migration and invasion (CXCL8, CXCL3, CLU, IL24, COL3A1, MAPT, and ITGA7) were differentially expressed in the MeHg-treated group, indicating MeHg toxicity and mechanism of action. This study will provide insights into the prevention and treatment of pregnancy-related diseases caused by MeHg.
Assuntos
Poluentes Ambientais/toxicidade , Compostos de Metilmercúrio/toxicidade , Apoptose/efeitos dos fármacos , Morte Celular , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular , Feminino , Humanos , Integrinas , Interleucina-8 , Fator 2 Relacionado a NF-E2 , Estresse Oxidativo/efeitos dos fármacos , Gravidez , Espécies Reativas de Oxigênio/metabolismo , Testes de Toxicidade , Trofoblastos/citologia , Trofoblastos/efeitos dos fármacos , Trofoblastos/metabolismoRESUMO
The accumulation of cadmium (Cd) in the human body through food chain can lead to adverse pregnancy outcomes. In this study, Cd cytotoxicity and its mechanisms in HTR-8/SVneo cells were investigated. Cd disrupted the cellular submicrostructure and inhibited the cell viability in a time- and dose-dependent manner. The levels of reactive oxygen species, malondialdehyde content, and the activities of glutathione peroxidase (GSH-Px) and total superoxode dismutase (T-SOD) were concentration-dependently increased by Cd. In addition, Cd dose-dependently inducedcell apoptosis and decreased cell migration and invasion capacities. Finally, Cd significantly upregulated all the genes related to oxidative stress (SOD1, ROS1, and HSPA6), inflammatory response, cell cycle, apoptosis, and migration and invasion. This study will provide insights into the prevention and treatment of pregnancy-related diseases caused by Cd intoxication.
Assuntos
Cádmio , Trofoblastos , Cádmio/metabolismo , Cádmio/toxicidade , Feminino , Humanos , Estresse Oxidativo , Gravidez , Proteínas Tirosina Quinases/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Trofoblastos/metabolismoRESUMO
To systematically evaluate the efficiency and safety of Tanreqing Injection in the treatment of stroke-associated pneumonia(SAP). Seven domestic and foreign databases(CNKI, Wanfang, VIP, CBM, PubMed, Cochrane Library, EMbase) were retrieved from the establishment to July 2020. According to the inclusion and exclusion criteria, randomized controlled trial of the effect of Tanreqing Injection in the treatment of SAP was selected. NoteExpress software was used to screen out literatures. RevMan 5.4 software was used for data analysis. GRADE system was used to evaluate the evidence quality of the outcome indicators. A total of 1 755 cases in 21 studies were retrieved, including 879 cases in experimental group and 876 cases in control group. In general, the quality of stu-dies received was not high. According to Meta-analysis,(1) in terms of shortening the length of hospital stay, Tanreqing Injection combined with conventional western medicine was better than conventional western medicine(MD=-4.04, 95%CI[-4.43,-3.65], P<0.000 01);(2) in terms of increasing effective rate, Tanreqing Injection combined with conventional western medicine was better than conventional western medicine(RR=1.22, 95%CI[1.17, 1.27], P<0.000 01);(3) in terms of reducing inflammation indicators, Tanreqing Injection combined with conventional western medicine was better than conventional western medicine(MD_(CRP)=-10.75, 95%CI[-15.61,-5.88], P<0.000 01; MD_(WBC count)=-1.62, 95%CI[-2.55,-0.69], P=0.000 6; MD_(PCT)=-0.58, 95%CI[-0.89,-0.26], P=0.000 3];(4) in terms of improving symptoms and signs, Tanreqing Injection combined with conventional wes-tern medicine was better than conventional western medicine(MD_(cough)=-2.73, 95%CI[-4.93,-0.53], P=0.02; MD_(antipyretic)=-1.07, 95%CI[-1.17,-0.98), P<0.000 01];(5) in terms of decreasing the NIHSS scores, Tanreqing Injection combined with conventional western medicine was better than conventional western medicine(MD=-3.02, 95%CI[-4.91,-1.13], P=0.002);(6) in terms of adverse reactions, there was no statistically significant difference between Tanreqing Injection combined with conventio-nal western medicine compared with conventional western medicine treatment(RR=1.19, 95%CI[0.61,2.29], P=0.61). GRADE system showed that the evidence levels of above outcome indicators were low and extremely low. The results proved that Tanreqing Injection combined with conventional western medicine had a good advantage in the treatment of SAP, with better observation indicators better than western medicine conventional treatment, and no increase in the incidence of adverse reactions. However, this study had certain limitations. The overall quality of the included studies was low, which affected the reliability of the results. Therefore, the conclusions of this study shall be used cautiously.
Assuntos
Medicamentos de Ervas Chinesas , Pneumonia , Acidente Vascular Cerebral , Humanos , Pneumonia/tratamento farmacológico , Reprodutibilidade dos Testes , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/tratamento farmacológicoRESUMO
As an intermediate metabolite of pyrethroids, 3-phenoxybenzoic acid (3-PBA) is more toxic than its parent compounds and has been detected in milk, soil, and human urine. 3-PBA can be metabolized through microbial degradation, but the microbial co-metabolic enzymes and pathways involved in 3-PBA degradation are unclear. This study investigated the enzymes types and possible pathways in the co-metabolic degradation of 3-PBA by Aspergillus oryzae M-4. The enzymes involved in co-metabolic degradation of 3-PBA and its intermediate metabolites were induced, and existed extracellularly and intracellularly except the catechol-degrading enzyme. Inhibitors and inducers of these oxidases were used to examine the enzymes required for co-metabolic degradation of 3-PBA and its intermediate metabolites. 3-PBA is hydroxylated to produce 3-hydroxy-5-phenoxy benzoic acid through the catalytic actions of lignin peroxidase (LiP). Phenol and gallic acid, the metabolites of 3-PBA, are produced via cleavage of an ether bond under the catalytic actions of cytochrome P450 (CYP450) and LiP. Phenol can be converted to catechol by LiP; catechol and gallic acid are cleaved to form long-chain olefin acid or olefin aldehyde by dioxygenase and LiP. In corn flour, some of these enzyme activators such as FeCl3, 4-cumaric acid, veratryl alcohol and sodium periodate appeared to improve 3-PBA degradation. The results provide a reliable pathway and characteristics for co-metabolic microbial degradation of 3-PBA in food and the environment.
Assuntos
Aspergillus oryzae/enzimologia , Benzoatos/metabolismo , Alcenos/metabolismo , Catecóis/metabolismo , Ácido Gálico/metabolismo , Peroxidases/metabolismo , Fenol/metabolismoRESUMO
OBJECTIVE: To use gene chip technology to study the effects of evodiamine (EVO) on the gene expression profile of tongue squamous cell carcinoma (TSCC) CAL-27 cell line, for the purpose of analyzing the mechanisms underlying the effects of EVO on gene expression and functional regulation of TSCC cells at the gene level. METHOD: Differentially expressed genes in CAL-27 cells treated with EVO were detected using gene chip technology and analyzed using ingenuity pathway analysis. RESULTS: Microarray results showed that there were 1243 differentially expressed genes following treatment with CAL-27 cells; 684 genes were upregulated and 559 were downregulated. Classical pathway analysis revealed a total of 89 signal transduction pathways with upregulated gene set enrichment, including lipopolysaccharide/interleukin (IL)-1-mediated inhibition of retinoid X receptor (RXR) function, agrin interactions at neuromuscular junctions, cholecystokinin/gastrin-mediated signaling, toll-like receptor signaling, and IL-6 signaling. A total of 39 signal transduction pathways were enriched for the downregulated genes, including interferon signals, liver X receptor/RXR activation signals, and RhoGDI signals. In the disease and function analysis, the upregulated genes were enriched in viral infection, RNA virus replication, viral replication, cancer cell invasion, cell invasion, and other related functions, while downregulated genes were enriched in neuromuscular diseases, and leukocyte differentiation, antiviral response, connective tissue cell death and other functions. CONCLUSIONS: Gene chip analysis offers an effective means of screening differential gene expression between EVO-treated TSCCs and controls, thus providing a sound basis for further research.
Assuntos
Carcinoma de Células Escamosas/genética , Redes Reguladoras de Genes/efeitos dos fármacos , Quinazolinas/farmacologia , Neoplasias da Língua/genética , Carcinoma de Células Escamosas/tratamento farmacológico , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , Neoplasias da Língua/tratamento farmacológicoRESUMO
Low carrier mobility and lifetime in semiconductor polymers are some of the main challenges facing the field of organic photovoltaics (OPV) in the quest for efficient devices with high current density. Finding novel strategies such as device structure engineering is a key pathway toward addressing this issue. In this work, the light absorption and carrier collection of OPV devices are improved by employment of ZnO nanowire (NW) arrays with an optimum NW length (50 nm) and antireflection (AR) film with nanocone structure. The optical characterization results show that ZnO NW increases the transmittance of the electron transporting layer as well as the absorption of the polymer blend. Moreover, the as-deposited polymer blend on the ZnO NW array shows better charge transfer as compared to the planar sample. By employing PC70BM:PV2000 as a promising air-stable active-layer, power conversion efficiencies of 9.8% and 10.1% are achieved for NW devices without and with an AR film, indicating 22.5% and 26.2% enhancement in PCE as compared to that of planar device. Moreover, it is shown that the AR film enhances the water-repellent ability of the OPV device.
RESUMO
Users of electronic cigarettes (e-cigs) are exposed to particles and other gaseous pollutants. However, major knowledge gaps on the physico-chemical properties of such exposures and contradictory data in published literature prohibit health risk assessment. Here, the effects of product brand, type, e-liquid flavoring additives, operational voltage, and user puffing patterns on emissions were systematically assessed using a recently developed, versatile, e-cig exposure generation platform and state-of-the-art analytical methods. Parameters of interest in this systematic evaluation included two brands (A and B), three flavors (tobacco, menthol, and fruit), three types of e-cigs (disposable, pre-filled, and refillable tanks), two puffing protocols (4 and 2 s/puff), and four operational voltages (2.2-5.7 V). Particles were generated at a high number concentration (106-107 particles/cm3). The particle size distribution was bi-modal (â¼200 nm and 1 µm). Furthermore, organic species (humectants propylene glycol and glycerin, nicotine) that were present in e-liquid and trace metals (potassium and sodium) that were present on e-cig heating coil were also released into the emission. In addition, combustion-related byproducts, such as benzene and toluene, were also detected in the range of 100-38,000 ppbv/puff. Parametric analyzes performed in this study show the importance of e-cig brand, type, flavor additives, user puffing pattern (duration and frequency), and voltage on physico-chemical properties of emissions. This observed influence is indicative of the complexity associated with the toxicological screening of emissions from e-cigs and needs to be taken into consideration.
Assuntos
Poluentes Atmosféricos/análise , Sistemas Eletrônicos de Liberação de Nicotina , Vaping , Aerossóis , Benzeno/análise , Aromatizantes , Frutas , Glicóis/análise , Mentol , Metais/análise , Nicotina/análise , Tamanho da Partícula , Nicotiana , Tolueno/análiseRESUMO
BACKGROUND: Tungsten inert gas (TIG) welding represents one of the most widely used metal joining processes in industry. It has been shown to generate a large majority of particles at the nanoscale and to have low mass emission rates when compared to other types of welding. Despite evidence that TIG fume particles may produce reactive oxygen species (ROS), limited data is available for the time course changes of particle-associated oxidative stress in exposed TIG welders. METHODS: Twenty non-smoking male welding apprentices were exposed to TIG welding fumes for 60 min under controlled, well-ventilated settings. Exhaled breathe condensate (EBC), blood and urine were collected before exposure, immediately after exposure, 1 h and 3 h post exposure. Volunteers participated in a control day to account for oxidative stress fluctuations due to circadian rhythm. Biological liquids were assessed for total reducing capacity, hydrogen peroxide (H2O2), malondialdehyde (MDA), and 8-hydroxy-2'-deoxyguanosine (8-OHdG) concentrations at each time point. A linear mixed model was used to assess within day and between day differences. RESULTS: Significant increases in the measured biomarkers were found at 3 h post exposure. At 3 h post exposure, we found a 24 % increase in plasma-H2O2 concentrations ([95%CI: 4 % to 46 %], p = 0.01); a 91 % increase in urinary-H2O2 ([2 % to 258 %], p = 0.04); a 14 % increase in plasma-8-OHdG ([0 % to 31 %], p = 0.049); and a 45 % increase in urinary-8-OHdG ([3 % to 105 %], p = 0.03). Doubling particle number concentration (PNC) exposure was associated with a 22 % increase of plasma-8-OHdG at 3 h post exposure (p = 0.01). CONCLUSION: A 60-min exposure to TIG welding fume in a controlled, well-ventilated setting induced acute oxidative stress at 3 h post exposure in healthy, non-smoking apprentice welders not chronically exposed to welding fumes. As mass concentration of TIG welding fume particles is very low when compared to other types of welding, it is recommended that additional exposure metrics such as PNC are considered for occupational risk assessments. Our findings highlight the importance of increasing awareness of TIG welding fume toxicity, especially given the realities of welding workplaces that may lack ventilation; and beliefs among interviewed welders that TIG represents a cleaner and safer welding process.
Assuntos
Poluentes Ocupacionais do Ar/toxicidade , Exposição por Inalação/efeitos adversos , Exposição Ocupacional/efeitos adversos , Estresse Oxidativo/efeitos dos fármacos , Fumaça/efeitos adversos , Soldagem , Adolescente , Adulto , Biomarcadores/análise , Biomarcadores/sangue , Biomarcadores/urina , Testes Respiratórios , Desoxiguanosina/análogos & derivados , Desoxiguanosina/análise , Desoxiguanosina/sangue , Desoxiguanosina/urina , Humanos , Peróxido de Hidrogênio/análise , Peróxido de Hidrogênio/sangue , Peróxido de Hidrogênio/urina , Modelos Lineares , Masculino , Malondialdeído/análise , Malondialdeído/sangue , Malondialdeído/urina , Suíça , Testes de Toxicidade , Recursos Humanos , Adulto JovemRESUMO
Electronic cigarettes (e-cig) have been introduced as a nicotine replacement therapy and have gained increasing attention and popularity. However, while findings on possible toxicological implications continue to grow, major knowledge gaps on both the complex chemistry of the exposure and toxicity exist, prohibiting public health assessors from assessing risks. Here, a versatile electronic cigarette exposure generation system (Ecig-EGS) has been developed and characterized. Ecig-EGS allows generation of real world e-cig emission profiles under controlled operational conditions, real time monitoring and time-integrated particle/gas sampling for physico-chemical characterization, and toxicological assessment (both in vitro and in vivo). The platform is highly versatile and can be used with all e-cig types. It enables generation of precisely controlled e-cig exposure while critical operational parameters and environmental mixing conditions can be adjusted in a systematic manner to assess their impact on complex chemistry and toxicity of emissions. Results proved the versatility and reproducibility of Ecig-EGS. E-cig emission was found to contain 106-107 particles/cm3 with the mode diameter around 200 nm, under air change rate of 60/h. Elevated CO2 and volatile organic specie generation was also observed. Furthermore, environmental mixing conditions also influenced e-cig emission profile. The versatility of Ecig-EGS will enable linking of operational and environmental parameters with exposure chemistry and toxicology and help in assessing health risks.
Assuntos
Poluentes Atmosféricos , Sistemas Eletrônicos de Liberação de Nicotina , Material Particulado , Testes de Toxicidade/instrumentação , Poluentes Atmosféricos/análise , Poluentes Atmosféricos/toxicidade , Desenho de Equipamento , Humanos , Exposição por Inalação , Material Particulado/análise , Material Particulado/toxicidade , Reprodutibilidade dos Testes , Testes de Toxicidade/métodosRESUMO
Tungsten inert gas welding (TIG) represents one of the most widely used metal joining processes in industry. Its propensity to generate a greater portion of welding fume particles at the nanoscale poses a potential occupational health hazard for workers. However, current literature lacks comprehensive characterization of TIG welding fume particles. Even less is known about welding fumes generated by welding apprentices with little experience in welding. We characterized TIG welding fume generated by apprentice welders (N = 20) in a ventilated exposure cabin. Exposure assessment was conducted for each apprentice welder at the breathing zone (BZ) inside of the welding helmet and at a near-field (NF) location, 60cm away from the welding task. We characterized particulate matter (PM4), particle number concentration and particle size, particle morphology, chemical composition, reactive oxygen species (ROS) production potential, and gaseous components. The mean particle number concentration at the BZ was 1.69E+06 particles cm(-3), with a mean geometric mean diameter of 45nm. On average across all subjects, 92% of the particle counts at the BZ were below 100nm. We observed elevated concentrations of tungsten, which was most likely due to electrode consumption. Mean ROS production potential of TIG welding fumes at the BZ exceeded average concentrations previously found in traffic-polluted air. Furthermore, ROS production potential was significantly higher for apprentices that burned their metal during their welding task. We recommend that future exposure assessments take into consideration welding performance as a potential exposure modifier for apprentice welders or welders with minimal training.
Assuntos
Gases/análise , Exposição Ocupacional/análise , Tungstênio/análise , Soldagem , Poluentes Ocupacionais do Ar/análise , Humanos , Exposição por Inalação/análise , Masculino , Metais , Nanopartículas/análise , Tamanho da Partícula , Soldagem/instrumentação , Soldagem/métodosRESUMO
BACKGROUND: Nanoparticle (NPs) functionalization has been shown to affect their cellular toxicity. To study this, differently functionalized silver (Ag) and gold (Au) NPs were synthesised, characterised and tested using lung epithelial cell systems. METHODS: Monodispersed Ag and Au NPs with a size range of 7 to 10 nm were coated with either sodium citrate or chitosan resulting in surface charges from -50 mV to +70 mV. NP-induced cytotoxicity and oxidative stress were determined using A549 cells, BEAS-2B cells and primary lung epithelial cells (NHBE cells). TEER measurements and immunofluorescence staining of tight junctions were performed to test the growth characteristics of the cells. Cytotoxicity was measured by means of the CellTiter-Blue ® and the lactate dehydrogenase assay and cellular and cell-free reactive oxygen species (ROS) production was measured using the DCFH-DA assay. RESULTS: Different growth characteristics were shown in the three cell types used. A549 cells grew into a confluent mono-layer, BEAS-2B cells grew into a multilayer and NHBE cells did not form a confluent layer. A549 cells were least susceptible towards NPs, irrespective of the NP functionalization. Cytotoxicity in BEAS-2B cells increased when exposed to high positive charged (+65-75 mV) Au NPs. The greatest cytotoxicity was observed in NHBE cells, where both Ag and Au NPs with a charge above +40 mV induced cytotoxicity. ROS production was most prominent in A549 cells where Au NPs (+65-75 mV) induced the highest amount of ROS. In addition, cell-free ROS measurements showed a significant increase in ROS production with an increase in chitosan coating. CONCLUSIONS: Chitosan functionalization of NPs, with resultant high surface charges plays an important role in NP-toxicity. Au NPs, which have been shown to be inert and often non-cytotoxic, can become toxic upon coating with certain charged molecules. Notably, these effects are dependent on the core material of the particle, the cell type used for testing and the growth characteristics of these cell culture model systems.
Assuntos
Células Epiteliais/efeitos dos fármacos , Ouro/farmacologia , Pulmão/citologia , Nanopartículas Metálicas , Oxidantes/farmacologia , Prata/farmacologia , Brônquios/citologia , Linhagem Celular/efeitos dos fármacos , Membrana Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Sistema Livre de Células , Células Cultivadas , Quitosana/química , Meios de Cultura/química , Meios de Cultura/farmacologia , Células Epiteliais/metabolismo , Humanos , Nanopartículas Metálicas/efeitos adversos , Nanopartículas Metálicas/química , Oxidantes/química , Espécies Reativas de Oxigênio/metabolismoRESUMO
In the post-pandemic era, medical resources are uneven, and access to healthcare is complicated. Online medical platforms have become a solution to bridge the information gap and reduce hospital pressure. This study uses the stereotype content model and signaling theory to explore the impact of patient perception of patient decision making (PDM) on online medical service platforms. Also, it tests the moderating effect of physician image. We collected information on 12,890 physicians and 746,981 patient reviews from online medical platforms in China. Unsupervised machine learning was used to construct a topic model to extract patients' perceptions of physicians' competence and warmth. Meanwhile, the facial features of physicians, such as age, smile, and glasses, are recognized by convolutional neural networks. Finally, the influence of PDM concern on decision-making and the moderating effect of physician image were analyzed by multiple linear regression. The results of the study showed that (1) patients' perceptions of physicians' competence and warmth had a positive effect on decision-making; (2) physicians' age and wearing glasses enhanced the positive effect of perception on decision-making; and (3) however, physicians' smiles weakened the positive effect of perception on decision-making. This study provides new insights into patients' online physician selection, guides the construction and promotion of medical service platforms, and provides an effective avenue of exploration to alleviate the problem of uneven distribution of offline medical resources.
RESUMO
Introduction: Peripheral artery disease (PAD) is an increasingly common disease, causing significant complications for patients. Trimetazidine (TMZ) not only improves clinical symptoms in PAD patients but also facilitates angiogenesis in ischemic hind limbs. Our aim was to find the function of TMZ in promoting angiogenesis and tissue perfusion in ischemic rat skeletal muscle. Methods: The rats underwent femoral artery ligation (FAL) and then treated with TMZ and saline. Hematoxylin-eosin and Masson's trichrome stain in the ischemic gastrocnemius muscle to analyze muscle morphology and atrophy. To identify angiogenesis and the tissue perfusion, CD31 immunohistochemical staining and laser speckle contrast imaging was conducted. Additionally, hind limb motor ability was measured. Finally, qRT-PCR and Western blotting were used to statistically analyze the expression levels of HIF-1α and VEGF. Results: Our study demonstrated significant enhancement in angiogenesis and tissue perfusion after FAL when treated with TMZ compared to the saline group. Histologically, it mitigates ischemia-induced muscle atrophy and inflammation, as well as reduces fibrosis progression in the TMZ group. Additionally, hind limb motor ability improved in rats treated with TMZ during motor experiments. Discussion: It suggests that TMZ can promote angiogenesis and improve tissue perfusion in ischemic skeletal muscle of rats by activating the HIF-1α/VEGF signaling pathway. Additionally, it leads to significant improvement in ischemia-induced motor limitations in the hind limbs of rats.