Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 29
Filtrar
1.
Environ Sci Technol ; 58(3): 1462-1472, 2024 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-38155590

RESUMO

The 2021 WHO guidelines stress the importance of measuring ultrafine particles using particle number concentration (PNC) for health assessments. However, commonly used particle metrics such as aerodynamic diameter and number concentrations do not fully capture the diverse chemical makeup of complex particles. To address this issue, our study used high-throughput mass spectrometry to analyze the properties of cooking oil fumes (COFs) in real time and evaluate their impact on BEAS-2B cell metabolism. Results showed insignificant differences in COF number size distributions between soybean oil and olive oil (peak concentrations of 5.20 × 105/cm3), as well as between corn oil and peanut oil (peak concentrations of 4.35 × 105/cm3). Despite the similar major chemical components among the four COFs, variations in metabolic damage were observed, indicating that the relatively small amount of chemical components of COFs can also influence particle behavior within the respiratory system, thereby impacting biological responses. Additionally, interactions between accompanying gaseous COFs and particles may alter their chemical composition through various mechanisms, introducing additional chemicals and modifying existing proportions. Hence, the chemical composition and gaseous components of COFs hold equal importance to the particle number concentration (PNC) when assessing their impact on human health. The absence of these considerations in the current guidelines underscores a research gap. It is imperative to acknowledge that for a more comprehensive approach to safeguarding public health, guidelines must be regularly updated to reflect new scientific findings and robust epidemiological evidence.


Assuntos
Óleos , Material Particulado , Humanos , Material Particulado/análise , Culinária/métodos , Gases/análise , Alimentos
2.
Ren Fail ; 46(2): 2359640, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38832483

RESUMO

Research has shown that patients undergoing hemodialysis experience seasonal variations in their serum potassium levels. There was inconsistent seasonal fluctuation in serum potassium levels among the hemodialysis population across different locations. In the form of narrative review for the first time, the article discusses the seasonal changes of serum potassium in this population and its potential reasons, this article demonstrates that it is primarily attributable to seasonal dietary potassium intake. However, existing studies have not quantified seasonal dietary potassium intake, so the results are still speculative. Furthermore, future research ought to further expound upon the clinical implications of seasonal variations in serum potassium levels among dialysis patients, as well as other influencing mechanisms such as the pathophysiological causes of these seasonal changes, particularly those pertaining to dietary, geographical, and regional factors. These findings contribute to a more thorough interpretation of laboratory results in hemodialysis patients and provide important guidance for their individualized dietary management.


Assuntos
Potássio , Diálise Renal , Estações do Ano , Humanos , Potássio/sangue , Falência Renal Crônica/terapia , Falência Renal Crônica/sangue , Potássio na Dieta/administração & dosagem
3.
Nano Lett ; 23(11): 4908-4915, 2023 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-37216428

RESUMO

The electrocatalytic conversion of polysulfides is crucial to lithium-sulfur batteries and mainly occurs at triple-phase interfaces (TPIs). However, the poor electrical conductivity of conventional transition metal oxides results in limited TPIs and inferior electrocatalytic performance. Herein, a TPI engineering approach comprising superior electrically conductive layered double perovskite PrBaCo2O5+δ (PBCO) is proposed as an electrocatalyst to boost the conversion of polysulfides. PBCO has superior electrical conductivity and enriched oxygen vacancies, effectively expanding the TPI to its entire surface. DFT calculation and in situ Raman spectroscopy manifest the electrocatalytic effect of PBCO, proving the critical role of enhanced electrical conductivity of this electrocatalyst. PBCO-based Li-S batteries exhibit an impressive reversible capacity of 612 mAh g-1 after 500 cycles at 1.0 C with a capacity fading rate of 0.067% per cycle. This work reveals the mechanism of the enriched TPI approach and provides novel insight into designing new catalysts for high-performance Li-S batteries.

4.
Environ Sci Technol ; 57(51): 21593-21604, 2023 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-37955649

RESUMO

Decades of research have established the toxicity of soot particles resulting from incomplete combustion. However, the unique chemical compounds responsible for adverse health effects have remained uncertain. This study utilized mass spectrometry to analyze the chemical composition of extracted soot organics at three oxidation states, aiming to establish quantitative relationships between potentially toxic chemicals and their impact on human alveolar basal epithelial cells (A549) through metabolomics-based evaluations. Targeted analysis using MS/MS indicated that particles with a medium oxidation state contained the highest total abundance of compounds, particularly oxygen-containing polycyclic aromatic hydrocarbons (OPAHs) composed of fused benzene rings and unsaturated carbonyls, which may cause oxidative stress, characterized by the upregulation of three specific metabolites. Further investigation focused on three specific OPAH standards: 1,4-naphthoquinone, 9-fluorenone, and anthranone. Pathway analysis indicated that exposure to these compounds affected transcriptional functions, the tricarboxylic acid cycle, cell proliferation, and the oxidative stress response. Biodiesel combustion emissions had higher concentrations of PAHs, OPAHs, and nitrogen-containing PAHs (NPAHs) compared with other fuels. Quinones and 9,10-anthraquinone were identified as the dominant compounds within the OPAH category. This knowledge enhances our understanding of the compounds contributing to adverse health effects observed in epidemiological studies and highlights the role of aerosol composition in toxicity.


Assuntos
Poluentes Atmosféricos , Hidrocarbonetos Policíclicos Aromáticos , Compostos Policíclicos , Humanos , Compostos Policíclicos/análise , Fuligem/análise , Fuligem/química , Fuligem/toxicidade , Espectrometria de Massas em Tandem , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Pulmão , Oxigênio/análise , Metaboloma , Poluentes Atmosféricos/análise , Emissões de Veículos/análise
5.
Environ Sci Technol ; 57(49): 20460-20469, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-38019752

RESUMO

Biodiesel, derived from alkyl esters of vegetable oils or animal fats, has gained prominence as a greener alternative to diesel due to its reduced particle mass. However, it remains debatable whether biodiesel exposure has more severe health issues than diesel. This study performed high-resolution mass spectrometry to examine the detailed particle chemical compositions and lipidomics analysis of human lung epithelial cells treated with emissions from biodiesel and diesel fuels. Results show the presence of the peak substances of CHO compounds in biodiesel combustion that contain a phthalate ester (PAEs) structure (e.g., n-amyl isoamyl phthalate and diisobutyl phthalate). PAEs have emerged as persistent organic pollutants across various environmental media and are known to possess endocrine-disrupting properties in the environment. We further observed that biodiesel prevents triglyceride storage compared to diesel and inhibits triglycerides from becoming phospholipids, particularly with increased phosphatidylglycerols (PGs) and phosphatidylethanolamines (PEs), which potentially could lead to a higher probability of cancer metastasis.


Assuntos
Poluentes Atmosféricos , Emissões de Veículos , Animais , Humanos , Emissões de Veículos/análise , Biocombustíveis/análise , Metabolismo dos Lipídeos , Gasolina/análise , Poluentes Atmosféricos/análise
6.
J Environ Sci (China) ; 127: 389-398, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36522070

RESUMO

Aldehyde and ketone compounds are ubiquitous in the air and prone to adverse effects on human health. Cooking emission is one of the major indoor sources. Aiming to evaluate health risks associated with inhalation exposure to aldehyde and ketone compounds, 13 carbonyl compounds (CCs) released from heating 5 edible oils, 3 seasonings, and 2 dishes were investigated in a kitchen laboratory. For the scenarios of heating five types of oil, aldehydes accounted for 61.1%-78.0% of the total emission, mainly acetaldehyde, acrolein and hexanal. Comparatively, heating oil with added seasonings released greater concentrations of aldehyde and ketone compounds. The concentration enhancement of larger molecular aldehydes was significantly greater. The emission factors of aldehyde and ketone compounds for cooking the dish of chili fried meat were much greater compared to that of tomato fried eggs. Therefore, food materials also had a great impact on the aldehyde and ketone emissions. Acetone and acetaldehyde were the most abundant CCs in the kitchen. Acrolein concentrations ranged from 235.18 to 498.71 µg/m3, which was about 100 times greater compared to the guidelines provided by Office of Environmental Health Hazard Assessment (OEHHA). The acetaldehyde inhalation for adults was 856.83-1515.55 µg and 56.23-192.79 µg from exposure to chili fried meat and tomato fried eggs, respectively. This exceeds the reference value of 90 µg/day provided by OEHHA. The findings of this study provided scientific evidences for the roles of cooking emissions on indoor air quality and human health.


Assuntos
Poluentes Atmosféricos , Poluição do Ar em Ambientes Fechados , Adulto , Humanos , Poluentes Atmosféricos/análise , Cetonas , Acroleína , Culinária , Poluição do Ar em Ambientes Fechados/análise , Aldeídos/análise , Acetaldeído , Monitoramento Ambiental
7.
Environ Sci Technol ; 54(23): 14889-14898, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-32790286

RESUMO

Light absorption enhancement (Eabs) of black carbon (BC) is a key factor in global climate models and is impacted by brown carbon (BrC) and the lensing effect of coatings. We conducted an in-depth field study on Eabs for ambient aerosols at a monitoring point in Shanghai, China, by real-time aerosol optical property monitoring and high-performance liquid chromatography/diode array detector/quadrupole-time-of-flight mass spectrometry (HPLC/DAD/Q-ToF-MS) analysis. The results showed Eabs at λ = 530 nm caused by the lensing effect was about 1.39 ± 027, accounting for 18.84% of the total light absorption. In this study, BrC is classified as soluble BrC (soluble in both water and methanol) or insoluble BrC (insoluble in both water and methanol). Soluble BrC accounted for 13.68 ± 11.15% of the total aerosol light absorption. For the first time, we concluded that insoluble BrC can contribute more than 60 and 97% of total aerosol and BrC light absorption in port cities, respectively. The molecular analysis of soluble BrC identified N-containing aromatic compounds (4-nitrophenol, 4-nitrocatechol, methyl nitrophenol, methyl nitrocatechols, and nitro-1-naphthol) commonly observed in biomass burning emissions or biomass burning-impacted atmospheres. A series of components (C16H26O3S, C17H28O3S, C18H30O3S, and C19H32O3S) were determined to be emissions from nearby cargo ships filled with heavy fuel oil (HFO), which further confirmed that insoluble BrC emitted from cargo ships could be the largest contributor to Eabs. This study confirms the global significance of evaluating HFO used in port cities in climate models. The control measures of cargo ship emission should be considered for the related environmental and health issues in port cities.


Assuntos
Poluentes Atmosféricos , Carbono , Aerossóis/análise , Poluentes Atmosféricos/análise , Carbono/análise , China , Cidades , Monitoramento Ambiental , Metanol , Água
8.
Appl Opt ; 59(16): 4939-4952, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32543491

RESUMO

The Lyot coronagraph is a widely known astronomical instrument used to realize direct imaging of exoplanets, and designing transmittance of an apodizer and Lyot stop is the key to obtaining high-contrast imaging. In this paper a new (to the best of our knowledge) optimization procedure used to design the apodizer and Lyot stop in the Lyot coronagraph is proposed. A two-step optimization program is established to obtain the optimum transmittance of an apodizer and Lyot stop in a sequential way. By using the optimized apodizer and Lyot stop obtained through the proposed optimization procedure, both the stellar light and its diffraction light could be strongly suppressed. Numerical results indicate that such an optimized Lyot coronagraph can produce a 1e-10 extinction of the stellar light near the diffraction limit (1.59λ/D), and a high contrast imaging of 1e-07 could still be obtained even with the influence of light intensity of planets themselves. In addition, the two-step optimization procedure brings in two benefits. First, the two-step optimization is approximately 1000 times faster than the joint optimization method [J. Astron. Telesc. Instrum. Syst.2, 011012 (2016)2329-412410.1117/1.JATIS.2.1.011012]. Second, the optimum transmittance of the Lyot stop is binary, and therefore, the requirements of the production process are reduced, resulting in a greatly reduced cost. At the same time, the performance of the optimized Lyot coronagraph is also analyzed in the case of a monochromatic light incident and bandwidth light incident, and the effect of the diameter of the Lyot stop on the results is also discussed in this paper, which makes sense when designing a coronagraph.

9.
Appl Opt ; 57(18): 5168-5179, 2018 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-30117981

RESUMO

A meteorological moderate resolution sensor requires large field of view (FOV) and low distortion imaging. At present, a fixed-focus camera combined with a whiskbroom scanning mechanism or a fixed-focus multi-camera combined with pushbroom scanning mechanism is being used. Owing to the fixed focal length of the camera, a large FOV causes the difference of imaging distance and ground imaging angle between the nadir point and the edge of the FOV to be significantly large, resulting in a large difference in the resolution between the nadir point and the edge of the FOV. The study proposes to simultaneously adopt a distributed zoom concentric multiscale system to realize a large FOV, low distortion, and high quality imaging to coordinate with different compensation lenses to achieve a different FOV corresponding to different focal lengths, where the resolution drop between the nadir point and the edge of the FOV is reduced. To ensure the same illumination of the entire FOV, the entire system possesses the same F# with different FOVs exhibiting different entrance pupil diameters. The study analyzes the principle of aberration compensation of a concentric multiscale system when both the FOV and entrance pupil diameter are changed and completes three groups of optical design of different focal lengths with uniform F#. The results indicate that the system has advantages of low distortion and high imaging quality in the entire FOV. Moreover, the resolution drop in the entire FOV is reduced to approximately 50% of the traditional design scheme. To verify the implementability of the system, a set of prototype manufacturing and imaging experiments are conducted to prove that the system has satisfactory implementability, and the imaging quality is also satisfactory.

10.
Pharmacology ; 101(1-2): 1-8, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-28898893

RESUMO

OBJECTIVE: The study aims to explore the effects of artesunate on insulin-like growth factor-1 (IGF-1), Osteopontin (OPN), and C-telopeptides of type II collagen (CTX-II) in serum, synovial fluid (SF), and cartilage tissues of rats with osteoarthritis (OA). METHODS: OA models were established. Normal model, artesunate, and Viatril-S groups (20 rats respectively) were set. Enzyme-linked immunosorbent assay, IHC staining, and quantitative real-time polymerase chain reaction were conducted to calculate IGF-1, OPN, and CTX-II levels in serum, SF, and cartilage tissues of rats. The pathological changes in cartilage tissues were evaluated with Mankin score and Hematoxylin-Eosin staining. RESULTS: Compared with the normal group, the model group showed increased IGF-1 level; decreased OPN, CTX-II levels in the serum and SF; and contrary results were seen in the cartilage tissues. A gradual ascending IGF-1 level and descending OPN and CTX-II levels existed in the serum and SF in the artesunate and Viatril-S groups after 2 weeks. The model group showed the most obvious pathological changes and highest Mankin score compared with the other groups. Higher IGF-1 level and lower OPN, CTX-II levels were exhibited in the cartilage tissue in the artesunate and Viatril-S groups but not in the model group. CONCLUSION: Artesunate and Viatril-S inhibit OA development by elevating IGF-1 level and reducing OPN and CTX-II levels.


Assuntos
Artemisininas/farmacologia , Colágeno Tipo II/metabolismo , Fator de Crescimento Insulin-Like I/metabolismo , Osteoartrite/metabolismo , Osteopontina/metabolismo , Fragmentos de Peptídeos/metabolismo , Animais , Artemisininas/uso terapêutico , Artesunato , Cartilagem Articular/efeitos dos fármacos , Cartilagem Articular/patologia , Colágeno Tipo II/sangue , Colágeno Tipo II/genética , Feminino , Fator de Crescimento Insulin-Like I/genética , Masculino , Osteoartrite/sangue , Osteoartrite/tratamento farmacológico , Osteoartrite/patologia , Osteopontina/sangue , Osteopontina/genética , Fragmentos de Peptídeos/sangue , Fragmentos de Peptídeos/genética , RNA Mensageiro/metabolismo , Ratos Wistar , Líquido Sinovial/metabolismo
11.
Phys Med Biol ; 69(14)2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38955331

RESUMO

Objective.The trend in the medical field is towards intelligent detection-based medical diagnostic systems. However, these methods are often seen as 'black boxes' due to their lack of interpretability. This situation presents challenges in identifying reasons for misdiagnoses and improving accuracy, which leads to potential risks of misdiagnosis and delayed treatment. Therefore, how to enhance the interpretability of diagnostic models is crucial for improving patient outcomes and reducing treatment delays. So far, only limited researches exist on deep learning-based prediction of spontaneous pneumothorax, a pulmonary disease that affects lung ventilation and venous return.Approach.This study develops an integrated medical image analysis system using explainable deep learning model for image recognition and visualization to achieve an interpretable automatic diagnosis process.Main results.The system achieves an impressive 95.56% accuracy in pneumothorax classification, which emphasizes the significance of the blood vessel penetration defect in clinical judgment.Significance.This would lead to improve model trustworthiness, reduce uncertainty, and accurate diagnosis of various lung diseases, which results in better medical outcomes for patients and better utilization of medical resources. Future research can focus on implementing new deep learning models to detect and diagnose other lung diseases that can enhance the generalizability of this system.


Assuntos
Aprendizado Profundo , Processamento de Imagem Assistida por Computador , Pneumotórax , Pneumotórax/diagnóstico por imagem , Humanos , Processamento de Imagem Assistida por Computador/métodos , Tomografia Computadorizada por Raios X
12.
Heliyon ; 10(9): e30023, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38726131

RESUMO

Primary spontaneous pneumothorax (PSP) primarily affects slim and tall young males. Exploring the etiological link between chest wall structural characteristics and PSP is crucial for advancing treatment methods. In this case-control study, chest computed tomography (CT) images from patients undergoing thoracic surgery, with or without PSP, were analyzed using Artificial Intelligence. Convolutional Neural Network (CNN) model of EfficientNetB3 and InceptionV3 were used with transfer learning on the Imagenet to compare the images of both groups. A heatmap was created on the chest CT scans to enhance interoperability, and the scale-invariant feature transform (SIFT) was adopted to further compare the image level. A total of 2,312 CT images of 26 non-PSP patients and 1,122 CT images of 26 PSP patients were selected. Chest-wall apex pit (CAP) was found in 25 PSP and three non-PSP patients (p < 0.001). The CNN achieved a testing accuracy of 93.47 % in distinguishing PSP from non-PSP based on chest wall features by identifying the existence of CAP. Heatmap analysis demonstrated CNN's precision in targeting the upper chest wall, accurately identifying CAP without undue influence from similar structures, or inappropriately expanding or minimizing the test area. SIFT results indicated a 10.55 % higher mean similarity within the groups compared to between PSP and non-PSP (p < 0.001). In conclusion, distinctive radiographic chest wall configurations were observed in PSP patients, with CAP potentially serving as an etiological factor linked to PSP. This study accentuates the potential of AI-assisted analysis in refining diagnostic approaches and treatment strategies for PSP.

13.
Sci Total Environ ; 953: 176254, 2024 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-39277009

RESUMO

Increasing dust storms impact ecosystems and human health by resuspending dust and microplastics. Plastic pollution is a major global concern. This study examines the molecular composition and concentration of atmospheric microplastics and additives in Hohhot and Shanghai, China during dust and non-dust days using non-target and target LC-MS/MS analysis with Multiple Reaction Monitoring (MRM) methodology and a self-established plastic monomers database. In Hohhot, 98 microplastics and additives types were identified on dust days (41 unique) and 70 on non-dust days (10 unique), mainly PEG, HTPE, PET, PPG, and Nylon. The types fluctuate ranging from 35 to 65 due to dusty conditions. In Shanghai, 50 types were identified (no unique), with 25 to 30 types consistently present. Hohhot's microplastics concentration during dust days peaked at 3531.59 ng/m3, about three times higher than non-dust days (1669.17 ng/m3) and significantly higher than Shanghai's maximum of 589.85 ng/m3. Overall, microplastic monomers in both cities were mostly compounds with low unsaturation, indicating potential for long-term atmospheric persistence. Highly reactive monomers like HTPE, PEG, thrive on dust days in Hohhot due to insufficient light and strong winds. These conditions reduce photochemical reactivity, accelerate microplastic aging through collisions, and resuspend more microplastics from the soil, resulting in a wider variety of microplastics with different m/z and carbon contents during sandstorms. On non-dust days, microplastics have more concentrated m/z values, indicating that substances with similar chemical properties disperse more under normal conditions. These findings highlight the significant impact of dust storms on microplastics characteristics. SYNOPSIS: This study indicates that dust storms and regional differences can have significant impacts on the diversity and abundance of atmospheric microplastics.

14.
Environ Pollut ; 318: 120874, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36526053

RESUMO

Both brown carbon (BrC) and the non-absorbing components coated on black carbon (BC) aerosols can enhance the light absorption of BC aerosols. BrC is a complicated mixture of organic compounds and not well characterized, which hinders exploring the links between BrC and optical properties. We conducted an in-depth field study on optical properties of ambient aerosols at a monitoring site in Shanghai, China via real-time monitoring and offline analysis. Results showed that BrC caused light absorption coefficients were 3.3 ± 3.3 Mm-1, 2.2 ± 5.0 Mm-1, 1.2 ± 1.2 Mm-1 at λ = 370, 470 and 520 nm, respectively, accounting for 11%, 10%, 6% of the total aerosol absorption for the corresponding wavelengths. A larger proportion of long-chain aliphatic organosulfates (OSs, CnH2n+2O4S, (CH2)nO5S, (CH2)nO6S) with double bond equivalent (DBE) values of 0 or 1 accounted for 5-20% of the light absorption (λ = 365 nm) for soluble brown carbon (BrC), which were dominating for the days with less N-containing aromatic compounds appearing. Furthermore, the structure of CnH2n+2O4S, (CH2)nO5S, (CH2)nO6S were explored using target MS/MS of HPLC-Q-ToF-MS: (CH2)nO5S series, the most abundant family of OSs, were constructed by functionalizing a saturated hydrocarbon with one sulfate and one carbonyl group. CnH2n+2O4S series were oxidized with only one sulfate group in the aliphatic chain R. (CH2)nO6S series were proposed as aliphatic OSs with one ester group. We speculated aliphatic OSs were formed via acid catalyzed perhydrolysis of hydroperoxides derived from long-chain alkanes releasing from diesel fueled vehicles, followed by the reaction with sulfate anion radicals. Therefore, relevant technologies should be further explored to reduce the impacts from vehicle emissions.


Assuntos
Poluentes Atmosféricos , Poluentes Atmosféricos/análise , China , Carbono/análise , Espectrometria de Massas em Tandem , Monitoramento Ambiental/métodos , Aerossóis/análise , Sulfatos , Ésteres , Material Particulado/análise
15.
Sci Total Environ ; 900: 165575, 2023 Nov 20.
Artigo em Inglês | MEDLINE | ID: mdl-37499815

RESUMO

The ambient air quality of harbors area in Asia is commonly more polluted compared to other continents. The airborne pollutant is directly or indirectly related to a significant impact of traffic emissions. This study for the first time assessed the impacts on brown carbon (BrC) and volatile organic compounds (VOCs) from in-port liquid natural gas (LNG) tractor truck at harbor areas, via conducting real-time monitoring of VOCs characteristic and sampling for ambient air at a harbor (named as W harbor) in Shanghai, China, collecting emissions of in-port LNG tractor truck and miniCast in laboratory, as well as statistics of external container diesel trucks in the port for further validation. HPLC/DAD/Q-Tof MS was adopted for sample analysis. Results showed that many CHO compounds were associated with vehicle exhausts. Among of them, aliphatic CHO compounds with low degree of unsaturation were identified as fatty acids and fatty acid methyl esters extensively existing in fuel combustion emissions. And non-aliphatic CHO compounds characterized by low O/C ratios (<0.17) identified for the harbor air came from the emissions of in-port LNG power trucks with low-speed driving and idling. The ambient average non-methane total hydrocarbons (NMHC) concentration (0.59 ppm) at W harbor was much greater than that for other areas in Shanghai. The higher ratios of toluene/benzene (3.30) and m/p-xylene/ethylbenzene (3.11) observed at W harbor implied instead of external container diesel trucks, the dominating contributing of internal LNG tractor trucks to ambient VOCs cannot be neglected. This study concluded that LNG is not as clean as it was expected. The LNG-fueled vehicles can produce strong light-absorption chromophores as well as high concentration of VOCs.

16.
ACS Appl Mater Interfaces ; 15(29): 34922-34930, 2023 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-37459462

RESUMO

The graphite/lithium metal hybrid anode shows great potential for achieving high-specific-energy lithium batteries. Despite the "dead lithium" problem caused by repeated stripping and deposition of Li component based on a conversion reaction, the degradation mechanism, based on intercalation reaction, of graphite in a hybrid anode is generally ignored. In this contribution, through in situ X-ray diffraction and in situ Raman analysis, we reveal that hysteresis and the mixed-phase state of graphite during deintercalation play a critical role in hybrid battery degradation. On the other hand, we successfully mitigated graphite degradation and increased the reversible capacity of the hybrid anode by introducing an inorganic-rich solid electrolyte interface. Remarkably, the hybrid anode (30% higher specific capacity compared to graphite) exhibits an average coulombic efficiency of 99.11% and retains 96.13% of initial capacity over 120 cycles. This work sheds new light on the advancement of high-specific-energy lithium secondary batteries.

17.
Front Nutr ; 10: 1241580, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37693241

RESUMO

In this paper, we study the effect of microbial fermentation on the nutrient composition and flavor of sweet potato slurry, different strains of Aspergillus niger, Saccharomyces cerevisiae, Lactobacillus plantarum, Bacillus coagulans, Bacillus subtilis, Lactobacillus acidophilus, and Bifidobacterium brevis were employed to ferment sweet potato slurry. After 48 h of fermentation with different strains (10% inoculation amount), we compared the effects of several strains on the nutritional and functional constituents (protein, soluble dietary fiber, organic acid, soluble sugar, total polyphenol, free amino acid, and sensory characteristics). The results demonstrated that the total sugar level of sweet potato slurry fell significantly after fermentation by various strains, indicating that these strains can utilize the nutritious components of sweet potato slurry for fermentation. The slurry's total protein and phenol concentrations increased significantly, and many strains demonstrated excellent fermentation performance. The pH of the slurry dropped from 6.78 to 3.28 to 5.95 after fermentation. The fermentation broth contained 17 free amino acids, and the change in free amino acid content is closely correlated with the flavor of the sweet potato fermentation slurry. The gas chromatography-mass spectrometry results reveal that microbial fermentation can effectively increase the kinds and concentration of flavor components in sweet potato slurry, enhancing its flavor and flavor profile. The results demonstrated that Aspergillus niger fermentation of sweet potato slurry might greatly enhance protein and total phenolic content, which is crucial in enhancing nutrition. However, Bacillus coagulans fermentation can enhance the concentration of free amino acids in sweet potato slurry by 64.83%, with a significant rise in fresh and sweet amino acids. After fermentation by Bacillus coagulans, the concentration of lactic acid and volatile flavor substances also achieved its highest level, which can considerably enhance its flavor. The above results showed that Aspergillus niger and Bacillus coagulans could be the ideal strains for sweet potato slurry fermentation.

18.
Adv Mater ; 34(26): e2202222, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35534022

RESUMO

Defective materials have been demonstrated to possess adsorptive and catalytic properties in lithium-sulfur (Li-S) batteries, which can effectively solve the problems of lithium polysulfides (LiPSs) shuttle and sluggish conversion kinetics during charging and discharging of Li-S batteries. However, there is still a lack of research on the quantitative relationship between the defect concentration and the adsorptive-catalytic performance of the electrode. In this work, perovskites Sr0.9 Ti1- x Mnx O3- δ (STMnx ) (x = 0.1-0.3) with different oxygen-vacancy concentrations are quantitatively regulated as research models. Through a series of tests of the adsorptive property and electrochemical performance, a quantitative relationship between oxygen-vacancy concentration and adsorptive-catalytic properties is established. Furthermore, the catalytic mechanism of oxygen vacancies in Li-S batteries is investigated using density functional theory calculations and in situ experiments. The increased oxygen vacancies can effectively increase the binding energy between perovskite and LiPSs, reduce the energy barrier of LiPSs decomposition reaction, and promote LiPSs conversion reaction kinetics. Therefore, the perovskite STMn0.3  with high oxygen-vacancy concentrations exhibits excellent LiPSs adsorptive and catalytic properties, realizing high-efficiency Li-S batteries. This work is helpful to realize the application of the quantitative regulation strategy of defect engineering in Li-S batteries.

19.
Sci Total Environ ; 853: 158385, 2022 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-36055512

RESUMO

Cooking oil fume (COF) is an important source of indoor and outdoor air pollutants. COF generates a large number of organic compounds through volatilization and thermal oxidation, mainly including acids, alcohols, aldehydes and polycyclic aromatic hydrocarbons (PAHs), which can contribute 10 %-35 % to airborne organic particles in urban areas. COF not only affects human health owning to their small sizes, but also may absorb incident light due to the presence of brown carbon (BrC) chromophores in organic components. Therefore, we investigated size distributions and light absorption properties of particles produced from heating four types of edible oil. Results showed over 75 % of COF particles belonged to ultrafine particles (UFPs) and capable of absorbing light. The particle number size distributions for heating all edible oils were bimodal lognormal distribution, and the two mode diameters were within 27.9-32.2 nm and 187.7-299.6 nm. Both real-time monitoring and offline analyzing results show the average absorption coefficients of particles generated from heating soybean oil were much greater compare to those of heating other three edible oils. The mean AAE370/520 for heating soybean oil, olive oil, corn oil and peanut oil were 1.877, 1.669, 1.745 and 1.288, respectively, indicating the presence of BrC chromophores. A large proportion of BrC identified by HPLC-DAD-Q-TOF-MS only contain carbon, hydrogen and oxygen, which are CnH2nO2, CnH2n-2O2, CnH2n-4O2 and CnH2n-6O2 (9

Assuntos
Poluentes Atmosféricos , Hidrocarbonetos Policíclicos Aromáticos , Humanos , Material Particulado/análise , Calefação , Metanol , Óleo de Soja , Óleo de Milho , Azeite de Oliva , Óleo de Amendoim , Poluentes Atmosféricos/análise , Aerossóis/análise , Óleos , Gases , Carbono , Oxigênio , Hidrogênio , Aldeídos , Ácidos Graxos , Monitoramento Ambiental/métodos
20.
ACS Nano ; 16(12): 20891-20901, 2022 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-36378080

RESUMO

For developing the reversible lithium metal anode, constructing an ideal solid electrolyte interphase (SEI) by regulating the Li+ solvation structure is a powerful way to overcome the major obstacles of lithium dendrite and limited Coulombic efficiency (CE). Herein, spherical mesoporous molecular sieve MCM-41 nanoparticles are coated on a commercial PP separator and used to regulate the Li+ solvation structure for lithium metal batteries (LMBs). The regulated solvation structure exhibits an agminated state with more contact ion pairs (CIPs) and ionic aggregates (AGGs), which successfully construct a homogeneous inorganic-rich SEI in the lithium anode. Meanwhile, the regulated solvation structure weakens the interaction between the solvents and Li+, resulting in low Li+ desolvation energy and uniform Li deposition. Thus, a high CE (∼96.76%), dendrite-free Li anode, and stable Li plating/stripping cycling for approximately 1000 h are achieved in the regulated carbonate-based electrolyte without any additives. Therefore, regulating the Li+ solvation structure in the electrolyte by employing a mesoporous material is a forceful way to construct an ideal SEI and harness lithium metal.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA