Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 697
Filtrar
1.
Environ Monit Assess ; 196(5): 463, 2024 Apr 20.
Artículo en Inglés | MEDLINE | ID: mdl-38642156

RESUMEN

In this study, the levels of sulfur dioxide (SO2) and nitrogen dioxide (NO2) were measured indoors and outdoors using passive samplers in Tymar village (20 homes), an industrial area, and Haji Wsu (15 homes), a non-industrial region, in the summer and the winter seasons. In comparison to Haji Wsu village, the results showed that Tymar village had higher and more significant mean SO2 and NO2 concentrations indoors and outdoors throughout both the summer and winter seasons. The mean outdoor concentration of SO2 was the highest in summer, while the mean indoor NO2 concentration was the highest in winter in both areas. The ratio of NO2 indoors to outdoors was larger than one throughout the winter at both sites. Additionally, the performance of machine learning (ML) approaches: multiple linear regression (MLR), artificial neural network (ANN), and random forest (RF) were compared in predicting indoor SO2 concentrations in both the industrial and non-industrial areas. Factor analysis (FA) was conducted on different indoor and outdoor meteorological and air quality parameters, and the resulting factors were employed as inputs to train the models. Cross-validation was applied to ensure reliable and robust model evaluation. RF showed the best predictive ability in the prediction of indoor SO2 for the training set (RMSE = 2.108, MAE = 1.780, and R2 = 0.956) and for the unseen test set (RMSE = 4.469, MAE = 3.728, and R2 = 0.779) values compared to other studied models. As a result, it was observed that the RF model could successfully approach the nonlinear relationship between indoor SO2 and input parameters and provide valuable insights to reduce exposure to this harmful pollutant.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire Interior , Contaminación del Aire , Dióxido de Azufre/análisis , Dióxido de Nitrógeno/análisis , Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente/métodos , Contaminación del Aire/análisis , Estaciones del Año , Contaminación del Aire Interior/análisis
2.
Food Chem ; 449: 138944, 2024 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-38613993

RESUMEN

Sulfite addition is a common tool for ensuring wines' oxidative stability via the activity of its free and weakly bound molecular fraction. As a nucleophile, bisulfite forms covalent adducts with wine's most relevant electrophiles, such as carbonyls, polyphenols, and thiols. The equilibrium in these reactions is often represented as dissociation rather than formation. Recent studies from our laboratory demonstrate, first, the acetaldehyde sulfonate dissociation, and second, the chemical stability of cysteine and epicatechin sulfonates under wine aging conditions. Thus, the objective of this study was to monitor by 1H NMR the binding specificity of known carbonyl-derived SO2 binders (acetaldehyde and pyruvic acid) in the presence of S-containing compounds (cysteine and glutathione). We report that during simulated wine aging, the sulfur dioxide that is rapidly bound to carbonyl compounds will be released and will bind to cysteine and glutathione, demonstrating the long-term sulfur dioxide binding potential of S-containing compounds. These results are meant to serve as a complement to existing literature reviews focused on molecular markers related to wines' oxidative stability and emphasize once more the importance of S-containing compounds in wine aging chemical mechanisms.

3.
Chemosphere ; 355: 141809, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38548080

RESUMEN

This study presents a novel approach that integrates ozone-driven chemical oxidation to convert NO into soluble NO2, followed by the simultaneous absorption of NO2 and SO2 into a CaCO3-based slurry using the redox catalyst potassium iodide (KI). Using cyclic voltammetry, we demonstrate the redox properties of the I2/2I- couple, which facilitates NO2 reduction into soluble NO2- and catalyst regeneration through sulfite (SO32-)-driven reduction, thus establishing a closed catalytic cycle within the components of flue gas. In lab-scale wet-scrubbing tests, we explore the effect of various operational parameters (i.e., KI concentration, pH, and SO2 concentration), with a 15 h stability test demonstrating >60% NOx and >99% SO2 removal efficiency when the pH is controlled between 7.5 and 8.5. A successful pilot-scale implementation conducted at an inlet flow rate of 1000 m3 h-1 further confirmed the reproducibility of the proposed redox-catalytic cycle. Our study offers a cost-effective, sustainable, and scalable solution for effectively mitigating NOx and SO2 emissions at low temperatures.


Asunto(s)
Óxidos de Nitrógeno , Dióxido de Azufre , Óxidos de Nitrógeno/química , Dióxido de Azufre/química , Dióxido de Nitrógeno , Yoduro de Potasio , Reproducibilidad de los Resultados , Oxidación-Reducción
4.
Angew Chem Int Ed Engl ; : e202401953, 2024 Mar 21.
Artículo en Inglés | MEDLINE | ID: mdl-38512876

RESUMEN

Salts of protonated sulfur dioxide were synthesized by recrystallization of [FS(OX)2][SbF6] (X=H, D) in aprotic solvents at low temperatures. Hemiprotonated sulfur dioxide [(SO2)2H][Sb2F11] was obtained from the solvent SO2 and the monoprotonated sulfur dioxide [OSOD][Sb2F11], using 1,1,1,2-tetrafluoroethane as solvent. For both compounds, single crystals were obtained and an X-ray structure analysis was conducted. Furthermore, the salts were characterized by Raman spectroscopy and the results were discussed together with quantum chemical calculations on the M06-2X/aug-cc-pVTZ level of theory.

5.
J Environ Manage ; 356: 120729, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38537464

RESUMEN

The recovery of valuable metals from spent lithium-ion batteries (LIBs) is crucial for environmental protection and resource optimization. In the traditional recovery process of spent LIBs, the leaching of high-valence metals has the problems of high cost and limited reagent utilization, and some valuable metals are lost in the subsequent purification process of the leaching solution. To reduce the cost of reagents, this study proposes the use of low-cost SO2 as a reagent combined with pressure leaching to efficiently recover high-valence metals from delithiated materials of spent LIBs, while selective solvent extraction is used to remove trace impurities in the leaching solution to avoid the loss of valuable metals. Experimental results demonstrated that by optimizing the conditions to 0.25 MPa SO2 partial pressure and 60 min reaction time at 70 °C, the leaching efficiencies for Ni, Co, and Mn reached 99.6%, 99.3%, and 99.6%, respectively. The kinetic study indicated that the leaching process was diffusion-controlled. Furthermore, the delithiated materials were used to completely utilize the residual SO2 in the solution to obtain a high concentration Ni-Co-Mn rich solution. Subsequently, Fe and Al impurities were deeply removed through a synergistic extraction of Di-2-ethylhexyl phosphoric acid (D2EHPA) and tributyl phosphate (TBP) without loss of valuable metals, achieving a high-purity Ni-Co-Mn solution. The process developed based on this work has the characteristics of environmental friendliness, high valuable metal recovery, and high product purity, providing a reference technical method for the synergistic treatment of waste SO2 flue gas with spent LIBs and the deep purification of impurities in spent LIBs.


Asunto(s)
Litio , Reciclaje , Reciclaje/métodos , Metales , Suministros de Energía Eléctrica , Cinética
6.
Redox Biol ; 71: 103124, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38503216

RESUMEN

OBJECTIVE: Cardiomyocyte senescence is an important contributor to cardiovascular diseases and can be induced by stressors including DNA damage, oxidative stress, mitochondrial dysfunction, epigenetic regulation, etc. However, the underlying mechanisms for the development of cardiomyocyte senescence remain largely unknown. Sulfur dioxide (SO2) is produced endogenously by aspartate aminotransferase 2 (AAT2) catalysis and plays an important regulatory role in the development of cardiovascular diseases. The present study aimed to explore the effect of endogenous SO2 on cardiomyocyte senescence and the underlying molecular mechanisms. APPROACH AND RESULTS: We interestingly found a substantial reduction in the expression of AAT2 in the heart of aged mice in comparison to young mice. AAT2-knockdowned cardiomyocytes exhibited reduced SO2 content, elevated expression levels of Tp53, p21Cip/Waf, and p16INk4a, enhanced SA-ß-Gal activity, and elevated level of γ-H2AX foci. Notably, supplementation with a SO2 donor ameliorated the spontaneous senescence phenotype and DNA damage caused by AAT2 deficiency in cardiomyocytes. Mechanistically, AAT2 deficiency suppressed the sulphenylation of signal transducer and activator of transcription 3 (STAT3) facilitated its nuclear translocation and DNA-binding capacity. Conversely, a mutation in the cysteine (Cys) 259 residue of STAT3 blocked SO2-induced STAT3 sulphenylation and subsequently prevented the inhibitory effect of SO2 on STAT3-DNA-binding capacity, DNA damage, and cardiomyocyte senescence. Additionally, cardiomyocyte (cm)-specific AAT2 knockout (AAT2cmKO) mice exhibited a deterioration in cardiac function, cardiomegaly, and cardiac aging, whereas supplementation with SO2 donors mitigated the cardiac aging and remodeling phenotypes in AAT2cmKO mice. CONCLUSION: Downregulation of the endogenous SO2/AAT2 pathway is a crucial pathogenic mechanism underlying cardiomyocyte senescence. Endogenous SO2 modifies STAT3 by sulphenylating Cys259, leading to the inhibition of DNA damage and the protection against cardiomyocyte senescence.


Asunto(s)
Enfermedades Cardiovasculares , Cisteína , Ratones , Animales , Cisteína/metabolismo , Miocitos Cardíacos/metabolismo , Dióxido de Azufre/farmacología , Enfermedades Cardiovasculares/metabolismo , Factor de Transcripción STAT3/metabolismo , Epigénesis Genética , ADN/metabolismo , Senescencia Celular
7.
Sci Rep ; 14(1): 6633, 2024 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-38503860

RESUMEN

Based on panel data from 210 prefecture-level cities in China from 2003 to 2021, this study employs the Time-Varying Differences-in-Differences (Time-Varying DID) approach to systematically examine the impact of smart city construction on pollution emissions and its underlying mechanisms. Additionally, the Propensity Score Matching-Differences-in-Differences method is employed for further validation. The research findings indicate that Smart City Construction (SCC) significantly reduces urban Volume of Sewage Discharge (VSD), sulfur dioxide emissions (SO2), and Emissions of Fumes and Dust (EFD), thereby mitigating pollution emissions (PE) and enhancing environmental quality. Mechanism analysis reveals that SCC achieves these effects through scale effects, structural effects, and technological effects. City heterogeneity analysis shows that provincial capital cities exhibit a stronger suppression effect on pollution emissions compared to non-provincial capital cities. Moreover, cities with lower levels of education attainment demonstrate a stronger ability to curb pollution emissions, while larger cities exhibit a more pronounced impact on mitigating pollution emissions. The marginal contributions of this study mainly consist of three aspects: Firstly, it enriches the literature on environmental impact factors by assessing, for the first time, the influence of SCC on PE. Secondly, a comprehensive approach is employed, integrating VSD, EFD, SO2 data, and economic and pollution data at the city level. Time-Varying DID is used to evaluate the policy effects of SCC. Finally, the study analyzes the impact mechanisms of SCC policy on environmental emissions from various perspectives.

8.
Adv Sci (Weinh) ; : e2309069, 2024 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-38532287

RESUMEN

A novel catalytic system for radical cross-coupling reactions based on copper and chiral Pyridyl-bis(imidazole) (PyBim) ligands is described. It overcomes the challenges of chemoselectivity and enantioselectivity, achieving a highly enantioselective vicinal sulfonyl-esterification reaction of alkenes involving sulfur dioxide. This strategy involves the use of earth-abundant metal catalyst, mild reaction conditions, a broad range of substrates (84 examples), high yields (up to 97% yield), and exceptional control over enantioselectivity. The reaction system is compatible with different types of radical precursors, including O-acylhydroxylamines, cycloketone oxime esters, aryldiazonium salts, and drug molecules. Chiral ligand PyBim is identified as particularly effective in achieving the desired high enantioselectivity. Mechanistic studies reveal that copper/PyBim system plays a vital role in C─O coupling, employing an outer-sphere model. In addition, the side arm effect of ligand is observed.

9.
J Hazard Mater ; 467: 133763, 2024 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-38359757

RESUMEN

Practical gas sensing application requires sensors to quantify target analytes with high sensitivity and reproducibility. However, conventional surface enhanced Raman scattering (SERS) sensor lacks reproducibility and quantification arising from variations of "hot spot" distribution and measurement conditions. Here, a ratio-dependent SERS sensor was developed for quantitative label-free gas sensing. Au@Ag-Au nanoparticles (NPs) were filtered onto anodic aluminum oxide (AAO) forming Au@Ag-Au@AAO SERS substrate. 4-MBA was encapsulated in the gap of Au@Ag-Au and served as the internal standard (IS) to calibrate SERS signal fluctuation for improved quantification ability. Combined with headspace sampling method, SO2 residue in traditional Chinese medicine (TCM) can be extracted and captured on the immediate vicinity of Au@Ag-Au surface. The intensity ratio I613 cm-1/I1078 cm-1 showed excellent linearity within the range of 0.5 mg/kg-500 mg/kg, demonstrating superior quantification performance for SO2 detection. Signals for concentration as low as 0.05 mg/kg of SO2 could be effectively collected, much lower than the strictest limit 10 mg/kg in Chinese Pharmacopoeia. Combined with a handheld Raman spectrometer, handy and quantitative TCM quality evaluation in aspect of SO2 residue was realized. This ratiometric SERS sensor functioned well in rapid on-site SO2 quantification, exhibiting excellent sensitivity and simple operability.


Asunto(s)
Nanopartículas del Metal , Nanopartículas del Metal/química , Oro/química , Reproducibilidad de los Resultados , Plata/química , Medicina Tradicional China
10.
J Hazard Mater ; 466: 133653, 2024 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-38301443

RESUMEN

Cadmium-contaminated water and food are seriously hazardous to the human health, especially liver injury. To understand the entanglement relationship between cadmium ion (Cd2+)-induced liver injury and the biomarker sulfur dioxide (SO2), a reliable bioanalytical tool is urgently needed, detecting SO2 to diagnose and evaluate the extent of liver injury in vivo. Herein, based on the Förster resonance energy transfer (FRET) mechanism, a novel SO2-tunable NIR ratiometric fluorescent probe (SMP) was developed, it was used to diagnose and treat liver injury induced by Cd2+ in biosystems. Specifically, it was constructed by conjugating a NIR dicyanoisophorone with a NIR benzopyranate as the donor and acceptor, respectively, and the ratiometric response of SO2- regulated by the Michael addition reaction. In addition, SMP exhibits rapid reaction time (<15 s), two well-resolved emission peaks (68 nm) with less cross-talk between channels for high imaging resolution, superior selectivity, and low limit of detection (LOD=80.3 nM) for SO2 detection. Impressively, SMP has been successfully used for intracellular ratiometric imaging of Cd2+-induced SO2 and diagnostic and therapeutic evaluation in liver injury mice models with satisfactory results. Therefore, SMP may provide a powerful molecular tool for revealing the occurrence and development relationship between SO2 and Cd2+-induced liver injury. ENVIRONMENTAL IMPLICATION: Cadmium ions are one of the well-known toxic environmental pollutants, which are enriched in the human body through inhalation of cadmium-contaminated air or from the food chain, leading to damage in various organs, especially liver injury. Therefore, we developed a novel fluorescent probe that can specifically detect SO2 in Cd2+-induced liver injury, which is critically important for the diagnosis and evaluation of Cd2+-induced liver injury diseases. The specific detection of SO2 of this probe has been successfully demonstrated in live HepG2 cells and Cd2+-induced liver injury mice.


Asunto(s)
Enfermedad Hepática Crónica Inducida por Sustancias y Drogas , Colorantes Fluorescentes , Ratones , Humanos , Animales , Cadmio/toxicidad , Células Hep G2 , Dióxido de Azufre/toxicidad , Células HeLa
11.
Food Chem ; 446: 138791, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38422638

RESUMEN

Acid-sensitive CdTe quantum dots-loaded alginate hydrogel (CdTe QDs-AH) beads were designed for the visual detection of SO2 residues. As proof of concept, two types of CdTe QDs were selected as model probes and embedded in AH beads. The entire test was performed within 25 min in a modified double-layer test tube with one bead fixed above the sample solution. Adding citric acid and heating at 70 ℃ for 20 min transformed the sulfites in the solution into SO2 gas, which then quenched the fluorescence of the CdTe QDs-AH beads. Using this assay, qualitative, naked-eye detection of SO2 residues was achieved in the concentration range of 25-300 ppm, as well as precise quantification was possible based on the difference in the average fluorescence brightness of the beads before and after the reaction. Five food types were successfully analysed using this method, which is simpler and more economical than existing methods, and does not require complex pretreatment.


Asunto(s)
Compuestos de Cadmio , Puntos Cuánticos , Puntos Cuánticos/química , Dióxido de Azufre , Compuestos de Cadmio/química , Hidrogeles , Telurio/química , Espectrometría de Fluorescencia/métodos
12.
Am J Physiol Lung Cell Mol Physiol ; 326(5): L539-L550, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38410870

RESUMEN

Soldiers deployed to Iraq and Afghanistan have a higher prevalence of respiratory symptoms than nondeployed military personnel and some have been shown to have a constellation of findings on lung biopsy termed post-deployment respiratory syndrome (PDRS). Since many of the subjects in this cohort reported exposure to sulfur dioxide (SO2), we developed a model of repetitive exposure to SO2 in mice that phenocopies many aspects of PDRS, including adaptive immune activation, airway wall remodeling, and pulmonary vascular (PV) disease. Although abnormalities in small airways were not sufficient to alter lung mechanics, PV remodeling resulted in the development of pulmonary hypertension and reduced exercise tolerance in SO2-exposed mice. SO2 exposure led to increased formation of isolevuglandins (isoLGs) adducts and superoxide dismutase 2 (SOD2) acetylation in endothelial cells, which were attenuated by treatment with the isoLG scavenger 2-hydroxybenzylamine acetate (2-HOBA). In addition, 2-HOBA treatment or Siruin-3 overexpression in a transgenic mouse model prevented vascular remodeling following SO2 exposure. In summary, our results indicate that repetitive SO2 exposure recapitulates many aspects of PDRS and that oxidative stress appears to mediate PV remodeling in this model. Together, these findings provide new insights regarding the critical mechanisms underlying PDRS.NEW & NOTEWORTHY We developed a mice model of "post-deployment respiratory syndrome" (PDRS), a condition in Veterans with unexplained exertional dyspnea. Our model successfully recapitulates many of the pathological and physiological features of the syndrome, revealing involvement of the ROS-isoLGs-Sirt3-SOD2 pathway in pulmonary vasculature pathology. Our study provides additional knowledge about effects and long-term consequences of sulfur dioxide exposure on the respiratory system, serving as a valuable tool for future PDRS research.


Asunto(s)
Modelos Animales de Enfermedad , Dióxido de Azufre , Animales , Ratones , Ratones Endogámicos C57BL , Superóxido Dismutasa/metabolismo , Superóxido Dismutasa/genética , Pulmón/patología , Pulmón/efectos de los fármacos , Pulmón/metabolismo , Masculino , Hipertensión Pulmonar/patología , Hipertensión Pulmonar/inducido químicamente , Hipertensión Pulmonar/metabolismo , Ratones Transgénicos , Remodelación Vascular/efectos de los fármacos , Sirtuina 3/metabolismo , Sirtuina 3/genética , Células Endoteliales/patología , Células Endoteliales/metabolismo , Células Endoteliales/efectos de los fármacos
13.
Chemistry ; 30(21): e202400557, 2024 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-38335153

RESUMEN

A novel electrochemical approach to access alkyl alkenesulfonates via a multicomponent reaction was developed. The metal-free method features easy-to-use SO2 stock solution forming monoalkylsulfites from alcohols with an auxiliary base in-situ. These intermediates serve a dual role as starting materials and as supporting electrolyte enabling conductivity. Anodic oxidation of the substrate styrene, radical addition of these monoalkylsulfites and consecutive second oxidation and deprotonation preserve the double bond and form alkyl ß-styrenesulfonates in a highly regio- and stereoselective fashion. The feasibility of this electrosynthetic method is demonstrated in 44 examples with yields up to 81 %, employing various styrenes and related substrates as well as a diverse set of alcohols. A gram-scale experiment underlines the applicability of this process, which uses inexpensive and readily available electrode materials.

14.
Artículo en Inglés | MEDLINE | ID: mdl-38374611

RESUMEN

Perceptron models have become integral tools for pattern recognition and classification problems in engineering fields. This study envisioned implementing artificial neural networks to forecast the performance of a mini-spray dryer for desulfurization activities. This work adopted k-fold cross-validation, a rigorous technique that evaluates model performance across multiple data segments. Several ANN models (21) were trained on data obtained from sulfation conditions, including sulfation temperature (120 °C-200 °C), slurry pH (4-12), stoichiometric ratio (0.5-2.5), slurry solid concentration (6%-14%) as the feed input and sulfur capture as the response. Three hundred synthetic datasets generated using the Gaussian noise data augmentation underwent a 10-fold cross-validation process before simulation on neural networks triggered by the logsig and tansig activation functions. The computation accuracy was further evaluated by altering the number of hidden cells from 2 to 10. The ANN architectures were assessed using statistical metrics such as mean square error (MSE), root mean square error (RMSE), mean absolute percentage error (MAPE), and the coefficient of determination (R2) techniques. Overall, error estimation suggests cross-validation and data augmentation are critical in efficient neural network generalization. The logsig function trained with 10 hidden cells presented closer data articulation when mapped onto actual values.


Asunto(s)
Redes Neurales de la Computación , Simulación por Computador , Predicción , Temperatura
15.
Korean J Physiol Pharmacol ; 28(2): 129-143, 2024 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-38414396

RESUMEN

Sulfur dioxide (SO2), a novel endogenous gas signaling molecule, is involved in the regulation of cardiac function. Exerting a key role in progression of hyperthyroidism-induced cardiomyopathy (HTC), myocardial fibrosis is mainly caused by myocardial apoptosis, leading to poor treatment outcomes and prognoses. This study aimed to investigate the effect of SO2 on the hyperthyroidism-induced myocardial fibrosis and the underlying regulatory mechanisms. Elisa, Masson staining, Western-Blot, transmission electron microscope, and immunofluorescence were employed to evaluate the myocardial interstitial collagen deposition, endoplasmic reticulum stress (ERS), apoptosis, changes in endogenous SO2, and Hippo pathways from in vitro and in vivo experiments. The study results indicated that the hyperthyroidism-induced myocardial fibrosis was accompanied by decreased cardiac function, and down-regulated ERS, apoptosis, and endogenous SO2-producing enzyme aspartate aminotransferase (AAT)1/2 in cardiac myocytes. In contrast, exogenous SO2 donors improved cardiac function, reduced myocardial interstitial collagen deposition, up-regulated AAT1/2, antagonized ERS and apoptosis, and inhibited excessive activation of Hippo pathway in hyperthyroid rats. In conclusion, the results herein suggested that SO2 inhibited the overactivation of the Hippo pathway, antagonized ERS and apoptosis, and alleviated myocardial fibrosis in hyperthyroid rats. Therefore, this study was expected to identify intervention targets and new strategies for prevention and treatment of HTC.

16.
Polymers (Basel) ; 16(4)2024 Feb 06.
Artículo en Inglés | MEDLINE | ID: mdl-38399835

RESUMEN

There have been many studies on surface acoustic wave (SAW) sensors for detecting sulfur-containing toxic or harmful gases. This paper aims to give an overview of the current state of polymer films used in SAW sensors for detecting deleterious gases. By covering most of the important polymer materials, the structures and types of polymers are summarized, and a variety of devices with different frequencies, such as delay lines and array sensors for detecting mustard gas, hydrogen sulfide, and sulfur dioxide, are introduced. The preparation method of polymer films, the sensitivity of the SAW gas sensor, the limit of detection, the influence of temperature and humidity, and the anti-interference ability are discussed in detail. The advantages and disadvantages of the films are analyzed, and the potential application of polymer films in the future is also forecasted.

17.
Sci Total Environ ; 917: 170457, 2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-38307278

RESUMEN

Mercury (Hg) is naturally released by volcanoes and geothermal systems, but the global flux from these natural sources is highly uncertain due to a lack of direct measurements and uncertainties with upscaling Hg/SO2 mass ratios to estimate Hg fluxes. The 2021 and 2022 eruptions of Fagradalsfjall volcano, southwest Iceland, provided an opportunity to measure Hg concentrations and fluxes from a hotspot/rift system using modern analytical techniques. We measured gaseous Hg and SO2 concentrations in the volcanic plume by near-source drone-based sampling and simultaneous downwind ground-based sampling. Mean Hg/SO2 was an order of magnitude higher at the downwind locations relative to near-source data. This was attributed to the elevated local background Hg at ground level (4.0 ng m-3) likely due to emissions from outgassing lava fields. The background-corrected plume Hg/SO2 mass ratio (5.6 × 10-8) therefore appeared conservative from the near-source to several hundred meters distant, which has important implications for the upscaling of volcanic Hg fluxes based on SO2 measurements. Using this ratio and the total SO2 flux from both eruptions, we estimate the total mass of gaseous Hg released from the 2021 and 2022 Fagradalsfjall eruptions was 46 ± 33 kg, equivalent to a flux of 0.23 ± 0.17 kg d-1. This is the lowest Hg flux estimate in the literature for active open-conduit volcanoes, which range from 0.6 to 12 kg d-1 for other hotspot/rift volcanoes, and 0.5-110 kg d-1 for arc volcanoes. Our results suggest that Icelandic volcanic systems are fed from an especially Hg-poor mantle. Furthermore, we demonstrate that the aerial near-source plume Hg measurement is feasible with a drone-based active sampling configuration that captures all gaseous and particulate Hg species, and recommend this as the preferred method for quantifying volcanic Hg emissions going forward.

18.
Environ Sci Pollut Res Int ; 31(11): 16805-16818, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38324157

RESUMEN

The vertical environmental reform in China has led to the change of environmental management system from territorial management model to vertical management model. This study uses the data of 263 prefecture-level cities in China to examine the effects of China's vertical environmental reform on pollutant emissions, including industrial sulfur dioxide, wastewater emissions, and industrial fumes emissions. The findings demonstrate that vertical environmental reform resulted in a reduction in industrial sulfur dioxide, wastewater emissions, and industrial fumes emissions. And the governance effects is gradually enhanced with the passage of time, which are long-lasting effects. The above conclusions are still valid after a series of robust estimates including mitigating selection bias, placebo test, changing the dependent variables, and mitigating heterogeneous treatment effects. According to heterogeneity analysis, the vertical environmental reform has reduced the increase of pollutants caused by financial pressure and official associations, and treats border pollution problems more effectively. Under the decentralized governance system, the implementation of vertical environmental management helps to reduce local pollutant emissions. This conclusion provides the latest evidence from China for the academic debate on the advantages and disadvantages of territorial environmental management and vertical environmental management and also provides policy implications for the government's environmental governance.


Asunto(s)
Contaminantes Atmosféricos , Contaminantes Ambientales , Contaminantes Ambientales/análisis , Contaminantes Atmosféricos/análisis , Dióxido de Azufre/análisis , Aguas Residuales , Conservación de los Recursos Naturales , Política Ambiental , China , Contaminación Ambiental/análisis , Ciudades
19.
Semin Arthritis Rheum ; 65: 152365, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38232624

RESUMEN

INTRODUCTION: Rheumatoid arthritis (RA) is a common autoimmune disease with a complex and poorly understood etiology that includes genetic, hormonal, and environmental factors. OBJECTIVE: Our objective was to assess current literature that investigated the association between exposure to environmental and occupational air pollutants and RA-related biomarkers rheumatoid factor (RF) and anti-citrullinated peptide antibody (ACPA). DESIGN: PubMed and Web of Science were used to identify epidemiological studies that measured or estimated air pollution and at least one RA biomarker. Information was charted for comparison of evidence, including pollutant(s) studied, exposure assessment, biomarker measurement, analysis method, study population, size, dates, adjustment variables, and findings. RESULTS: Several common air pollutants (including two mixtures) and a few dozen occupational inhalants were assessed in 13 eligible studies. Associations between industrial sulfur dioxide and particulate matter less than 2.5 µm in diameter with ACPA were observed most frequently, including associations between residential proximity to pollution sources and ACPA positivity. Consistency of associations with other pollutants was either not observed or limited to single studies. Three studies evaluated the modifying impact of SE alleles (a genetic factor associated with RA) and found that pollutant associations were stronger among participants positive for SE alleles. CONCLUSION: Based on mixed results, there was no consistent link between any single pollutant and RA-related biomarker outcomes. Comparisons across studies were limited by differences in study populations (e.g., by RA status, by sociodemographic groups) and study design (including designs focused on different sources of air pollution, methodological approaches with varying levels of potential exposure misclassification, and assessments of inconsistent biomarker cut-points). However, given that multiple studies reported associations between exposure to air pollution and RA biomarkers, continued exploration utilizing studies that can be designed with a more robust causal framework, including continued consideration of effect modification by genetic status, may be necessary.


Asunto(s)
Contaminantes Atmosféricos , Contaminación del Aire , Artritis Reumatoide , Contaminantes Ambientales , Humanos , Contaminantes Atmosféricos/efectos adversos , Contaminantes Atmosféricos/análisis , Artritis Reumatoide/epidemiología , Contaminación del Aire/efectos adversos , Contaminación del Aire/análisis , Factor Reumatoide , Biomarcadores/análisis , Contaminantes Ambientales/análisis
20.
Polymers (Basel) ; 16(2)2024 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-38276683

RESUMEN

A biodegradable polymer packaging system for 'Benitaka' table grapes (Vitis vinifera L.) was developed to inhibit the development of gray mold during refrigerated storage. The system consisted of packages and sachets containing Na2S2O5 to release sulfur dioxide (SO2), both produced with biodegradable films of starch, glycerol, and poly (adipate co-butylene terephthalate) (PBAT) produced via blown extrusion. The films were characterized in terms of thickness, density, mass loss in water, water vapor permeability, sorption isotherms, and mechanical properties. The table grapes were packed with biodegradable plastic bags containing SO2-releasing sachets inside. The experimental design was completely randomized, with four repetitions and five treatments: (a) control, without sachet containing Na2S2O5 and SiO2; (b) 2 g of Na2S2O5 + 2 g of SiO2; (c) 4 g of Na2S2O5 + 1 g of SiO2; (d) 4 g of Na2S2O5 + 2 g of SiO2; and (e) 4 g of Na2S2O5 + 4 g of SiO2. The bunches were stored in a refrigerated chamber at 1 ± 1 °C and relative humidity above 90%. The treatments were evaluated 30 and 45 days after the beginning of refrigerated storage and 3 days at room temperature. The grapes were evaluated based on the incidence of gray mold, mass loss, stem browning, shattered berries, and berry bleaching. The data were subjected to the analysis of variance, and the means were compared using Tukey's test at 5%. The biodegradable films had good processability during the production via blown extrusion, with good physical properties to be used in the packaging of grapes and the production of SO2-releasing sachets. The biodegradable polymer packaging system (biodegradable plastic bags + SO2-releasing sachets) inhibited the development of gray mold on 'Benitaka' table grapes for 45 days at 1 °C, preserving their quality, with low mass loss, few shattered berries, and rachis freshness.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...