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1.
Brain Res Bull ; 214: 110989, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38825252

RESUMO

Parkinson's disease (PD) is a chronic neurodegenerative disease with unclear pathogenesis that involves neuroinflammation and intestinal microbial dysbiosis. Intercellular adhesion molecule-1 (ICAM-1), an inflammatory marker, participates in neuroinflammation during dopaminergic neuronal damage. However, the explicit mechanisms of action of ICAM-1 in PD have not been elucidated. We established a subacute PD mouse model by the intraperitoneal injection of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and observed motor symptoms and gastrointestinal dysfunction in mice. Immunofluorescence was used to examine the survival of dopaminergic neurons, expression of microglial and astrocyte markers, and intestinal tight junction-associated proteins. Then, we use 16 S rRNA sequencing to identify alterations in the microbiota. Our findings revealed that ICAM-1-specific antibody (Ab) treatment relieved behavioural defects, gastrointestinal dysfunction, and dopaminergic neuronal death in MPTP-induced PD mice. Further mechanistic investigations indicated that ICAM-1Ab might suppress neuroinflammation by inhibiting the activation of astrocytes and microglia in the substantia nigra and relieving colon barrier impairment and intestinal inflammation. Furthermore, 16 S rRNA sequencing revealed that the relative abundances of bacterial Firmicutes, Clostridia, and Lachnospiraceae were elevated in the PD mice. However, ICAM-1Ab treatment ameliorated the MPTP-induced disorders in the intestinal microbiota. Collectively, we concluded that the suppressing ICAM-1 might lead to the a significant decrease of inflammation and restore the gut microbial community, thus ameliorating the damage of DA neurons.


Assuntos
Neurônios Dopaminérgicos , Molécula 1 de Adesão Intercelular , Camundongos Endogâmicos C57BL , Animais , Neurônios Dopaminérgicos/metabolismo , Neurônios Dopaminérgicos/patologia , Neurônios Dopaminérgicos/efeitos dos fármacos , Molécula 1 de Adesão Intercelular/metabolismo , Camundongos , Masculino , Modelos Animais de Doenças , Doenças Neuroinflamatórias/metabolismo , Microbioma Gastrointestinal/fisiologia , Microbioma Gastrointestinal/efeitos dos fármacos , 1-Metil-4-Fenil-1,2,3,6-Tetra-Hidropiridina/farmacologia , Inflamação/metabolismo , Substância Negra/metabolismo , Substância Negra/efeitos dos fármacos , Substância Negra/patologia , Microglia/metabolismo , Astrócitos/metabolismo , Astrócitos/efeitos dos fármacos , Transtornos Parkinsonianos/metabolismo , Intoxicação por MPTP/metabolismo , Intoxicação por MPTP/patologia
2.
Water Res ; 260: 121912, 2024 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-38875858

RESUMO

Numerous investigations have illuminated the profound impact of phosphate on the adsorption of uranium, however, the effect of phosphate-mediated surface modification on the reactivity of zero-valent iron (ZVI) remained enigmatic. In this study, a phosphate-modified ZVI (P-ZVIbm) was prepared with a facile ball milling strategy, and compared with ZVIbm, the U(VI) removal amount (435.2 mg/g) and efficiency (3.52×10-3 g·mg-1·min-1) of P-ZVIbm were disclosed nearly 2.0 and 54 times larger than those of ZVIbm respectively. The identification of products revealed that the adsorption mechanism dominated the removal process for ZVIbm, while the reactive modified layer strengthened both the adsorption pattern and reduction performance on P-ZVIbm. DFT calculation result demonstrated that the binding configuration shifted from bidentate binuclear to multidentate configuration, further shortening the Fe-U atomic distance. More importantly, the electron transferred is more accessible through the surface phosphate layer, and selectively donated to U(VI), accounting for the elevated reduction performance of P-ZVIbm. This investigation explicitly underscores the critical role of ZVI's surface microenvironment in the domain of radioactive metal ion mitigation and introduces a novel methodology to amplify the sequestration of U(VI) from aqueous environments.

3.
J Hazard Mater ; 476: 134952, 2024 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-38944985

RESUMO

Natural attenuation (NA) is of great significance for the remediation of contaminated groundwater, and how to identify NA patterns of toluene in aquifers more quickly and effectively poses an urgent challenge. In this study, the NA of toluene in two typical soils was conducted by means of soil column experiment. Based on column experiments, dissolved organic matter (DOM) was rapidly identified using fluorescence spectroscopy, and the relationship between DOM and the NA of toluene was established through structural equation modeling analysis. The adsorption rates of toluene in clay and sandy soil were 39 % and 26 %, respectively. The adsorption capacity and total NA capacity of silty clay were large. The occurrence of fluorescence peaks of protein-like components and specific products indicated the occurrence of biodegradation. Arenimonas, Acidovorax and Brevundimonas were the main degrading bacteria identified in Column A, while Pseudomonas, Azotobacter and Mycobacterium were the main ones identified in Column B. The pH, ORP, and Fe(II) were the most important factors affecting the composition of microbial communities, which in turn affected the NA of toluene. These results provide a new way to quickly identify NA of toluene.

4.
ACS Appl Mater Interfaces ; 16(17): 21828-21837, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38639177

RESUMO

Two-dimensional (2D) van der Waals materials are increasingly seen as potential catalysts due to their unique structures and unmatched properties. However, achieving precise synthesis of these remarkable materials and regulating their atomic and electronic structures at the most fundamental level to enhance their catalytic performance remain a significant challenge. In this study, we synthesized single-crystal bulk PtTe crystals via chemical vapor transport and subsequently produced atomically thin, large PtTe nanosheets (NSs) through electrochemical cathode intercalation. These NSs are characterized by a significant presence of Te vacancy pairs, leading to undercoordinated Pt atoms on their basal planes. Experimental and theoretical studies together reveal that Te vacancy pairs effectively optimize and enhance the electronic properties (such as charge distribution, density of states near the Fermi level, and d-band center) of the resultant undercoordinated Pt atoms. This optimization results in a significantly higher percentage of dangling O-H water, a decreased energy barrier for water dissociation, and an increased binding affinity of these Pt atoms to active hydrogen intermediates. Consequently, PtTe NSs featuring exposed and undercoordinated Pt atoms demonstrate outstanding electrocatalytic activity in hydrogen evolution reactions, significantly surpassing the performance of standard commercial Pt/C catalysts.

5.
Environ Sci Technol ; 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38319875

RESUMO

Light alkanes (LAs), typical VOCs existing in both stationary and mobile sources, pose significant environmental concerns. Although noble metal catalysts demonstrate strong C-H bond activation, their effectiveness in degrading LAs is hindered by inherent challenges, including poor chemical stability and water resistance. Here, from a new perspective, we propose a feasible strategy that adjusting the metal bond lengths within Pd clusters through partial substitution of smaller radius 3d transition metals (3dTMs) to prioritize the activation of low-energy C-C bonds within LAs. Benefiting from this, PdCo/CeO2 exhibits exceptional catalytic performance in propane degradation due to their high capacity for C-C cleavage stemming from the shorter Pd-Co length (2.51 Å) and lower coordination number (1.73), boosting the activation of α-H and ß-H of propane simultaneously and accelerating the mobility of postactivated oxygen species to prevent Pd center deep oxidation. The presence of 3dTMs on Pd clusters improves the redox and charge transfer ability of catalysts, resulting in an amplified generation of oxygen vacancies and facilitating the adsorption and activation of reactants. Mechanistic studies and DFT calculations suggest that the substitution of 3dTMs significantly accelerate C-C bond cleavage within C3 intermediates to generate the subsequent C2 and C1 intermediates, suppressing the generation of harmful byproducts.

6.
Phys Med Biol ; 69(2)2024 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-38086076

RESUMO

Objective. Convolutional neural networks (CNNs) have made significant progress in medical image segmentation tasks. However, for complex segmentation tasks, CNNs lack the ability to establish long-distance relationships, resulting in poor segmentation performance. The characteristics of intra-class diversity and inter-class similarity in images increase the difficulty of segmentation. Additionally, some focus areas exhibit a scattered distribution, making segmentation even more challenging.Approach. Therefore, this work proposed a new Transformer model, FTransConv, to address the issues of inter-class similarity, intra-class diversity, and scattered distribution in medical image segmentation tasks. To achieve this, three Transformer-CNN modules were designed to extract global and local information, and a full-scale squeeze-excitation module was proposed in the decoder using the idea of full-scale connections.Main results. Without any pre-training, this work verified the effectiveness of FTransConv on three public COVID-19 CT datasets and MoNuSeg. Experiments have shown that FTransConv, which has only 26.98M parameters, outperformed other state-of-the-art models, such as Swin-Unet, TransAttUnet, UCTransNet, LeViT-UNet, TransUNet, UTNet, and SAUNet++. This model achieved the best segmentation performance with a DSC of 83.22% in COVID-19 datasets and 79.47% in MoNuSeg.Significance. This work demonstrated that our method provides a promising solution for regions with high inter-class similarity, intra-class diversity and scatter distribution in image segmentation.


Assuntos
COVID-19 , Humanos , COVID-19/diagnóstico por imagem , Redes Neurais de Computação , Processamento de Imagem Assistida por Computador
7.
Adv Mater ; 35(29): e2301593, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37154063

RESUMO

Exposing active sites and optimizing their binding strength to reaction intermediates are two essential strategies to significantly improve the catalytic performance of 2D materials. However, pursuing an efficient way to achieve these goals simultaneously remains a considerable challenge. Here, using 2D PtTe2 van der Waals material with a well-defined crystal structure and atomically thin thickness as a model catalyst, it is observed that a moderate calcination strategy can promote the structural transformation of 2D crystal PtTe2 nanosheets (c-PtTe2 NSs) into oxygen-doped 2D amorphous PtTe2 NSs (a-PtTe2 NSs). The experimental and theoretical investigations cooperatively reveal that oxygen dopants can break the inherent Pt-Te covalent bond in c-PtTe2 NSs, thereby triggering the reconfiguration of interlayer Pt atoms and exposing them thoroughly. Meanwhile, the structural transformation can effectively tailor the electronic properties (e.g., the density of state near the Fermi level, d-band center, and conductivity) of Pt active sites via the hybridization of Pt 5d orbitals and O 2p orbitals. As a result, a-PtTe2 NSs with large amounts of exposed Pt active sites and optimized binding strength to hydrogen intermediates exhibit excellent activity and stability in hydrogen evolution reaction.

8.
Huan Jing Ke Xue ; 44(4): 2215-2222, 2023 Apr 08.
Artigo em Chinês | MEDLINE | ID: mdl-37040970

RESUMO

With the rapid development of urbanization in China, the number of gas stations in cities is increasing. The composition of oil products in gas stations is complex and diverse, and a series of pollutants will be generated in the process of oil diffusion. Polycyclic aromatic hydrocarbons (PAHs) produced by gas stations can pollute the nearby soil and affect human health. In this study, soil samples (0-20 cm) near 117 gas stations in Beijing were collected, and the contents of seven PAHs were analyzed. Based on the BP neural network model, the contents of PAHs in soil of Beijing gas stations in 2025 and 2030 were predicted. The results showed that the total concentrations of the seven PAHs were 0.01-3.53 mg·kg-1. The concentrations of PAHs were lower than the soil environmental quality risk control standard for soil contamination of development land (Trial) GB 36600-2018. At the same time, the toxic equivalent concentrations (TEQ) of the above seven PAHs were lower than the standard value (1 mg·kg-1) of the World Health Organization (WHO), which they indicate a lower risk to human health. The prediction results showed that the rapid development of urbanization had a positive correlation with the increase in soil PAHs content. By 2030, the content of PAHs in Beijing gas station soil will continue to grow. The predicted concentrations of PAHs in the soil of Beijing gas stations in 2025 and 2030 were 0.085-4.077 mg·kg-1and 0.132-4.412 mg·kg-1, respectively. The contents of seven PAHs were lower than the soil pollution risk screening value of GB 36600-2018; however, the concentration of PAHs increased over time.The contents of PAHs in Chaoyang, Fengtai, and Haidian were relatively higher, which requires further attention.

9.
Anal Methods ; 15(15): 1855-1860, 2023 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-36960734

RESUMO

Voltage-gated sodium channels (VGSCs) are widely expressed in various types of tumor and cancer cells, and NaV1.5 is overexpressed in highly metastatic breast cancer cells. There may be positive relations between the expression levels of NaV1.5 and breast cancer recurrence and metastasis. Herein, NaV1.5 was detected and localized on the surfaces of normal and cancer breast cells by the single molecule recognition imaging (SMRI) mode of atomic force microscopy (AFM). The results reveal that NaV1.5 was irregularly distributed on the surfaces of normal and cancer breast cells. The NaV1.5 has an area percentage of 0.6% and 7.2% on normal and cancer breast cells, respectively, which indicates that there is more NaV1.5 on cancer cells than on normal cells. The specific interaction forces and binding kinetics in the NaV1.5-antibody complex system were investigated with the single molecule force spectroscopy (SMFS) mode of AFM, indicating that the stability of the NaV1.5-antibody on normal breast cells is higher than that on cancer breast cells. All these results will be useful to study the interactions of other ion channel-antibody systems, and will also be useful to understand the role of sodium channels in tumor metastasis and invasion.


Assuntos
Neoplasias da Mama , Canais de Sódio Disparados por Voltagem , Humanos , Feminino , Recidiva Local de Neoplasia , Canais de Sódio Disparados por Voltagem/metabolismo , Linhagem Celular Tumoral
10.
Psychol Res Behav Manag ; 16: 683-700, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36926414

RESUMO

Purpose: This study investigates the association between the previous workplace ostracism of employees and their subsequent helping behavior by drawing on moral cleansing theory in the Chinese context, exploring the mediating roles of employees' guilt and perceived loss of moral credit and the moderating role of their moral identity symbolization. Sample and Method: The data were collected from a two-stage time-lagged survey of 284 Chinese employees. Regression analysis and the bootstrapping method are used in this article to examine the theoretical hypotheses. Results: The results indicate that employees' previous ostracism behaviors positively affected their guilt experience and perceived loss of moral credit. Subsequently, the relationship between employees' workplace ostracism and their helping behavior is mediated by guilt experience and perceived loss of moral credit. Furthermore, moral identity symbolization positively moderated the indirect "workplace ostracism-helping behavior" linkage via guilt and perceived loss of moral credits; in other words, for employees who have a higher degree of moral identity symbolization, the mediating effect is more significant, and vice versa. Conclusion: This study does not merely clarify the theoretical relationship between perpetrators' workplace ostracism and their helping behavior, which enriches the explanatory logic of related research on workplace ostracism and the cause of helping behavior, but also expand the application scope of moral cleansing theory. Further, we aim practically to bring enlightenment to human resource management reform, corporate culture construction, and positive behavior management.

11.
Metab Eng ; 76: 110-119, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36746296

RESUMO

p-Hydroxyacetophenone (p-HAP) and its glucoside picein are plant-derived natural products that have been extensively used in chemical, pharmaceutical and cosmetic industries owing to their antioxidant, antibacterial and antiseptic activities. However, the natural biosynthetic pathways for p-HAP and picein have yet been resolved so far, limiting their biosynthesis in microorganisms. In this study, we design and construct a biosynthetic pathway for de novo production of p-HAP and picein from glucose in E. coli. First, screening and characterizing pathway enzymes enable us to successfully establish functional biosynthetic pathway for p-HAP production. Then, the rate-limiting step in the pathway caused by a reversible alcohol dehydrogenase is completely eliminated by modulating intracellular redox cofactors. Subsequent host strain engineering via systematic increase of precursor supplies enables production enhancement of p-HAP with a titer of 1445.3 mg/L under fed-batch conditions. Finally, a novel p-HAP glucosyltransferase capable of generating picein from p-HAP is identified and characterized from a series of glycosyltransferases. On this basis, de novo biosynthesis of picein from glucose is achieved with a titer of 210.7 mg/L under fed-batch conditions. This work not only demonstrates a microbial platform for p-HAP and picein synthesis, but also represents a generalizable pathway design strategy to produce value-added compounds.


Assuntos
Vias Biossintéticas , Escherichia coli , Escherichia coli/genética , Escherichia coli/metabolismo , Vias Biossintéticas/genética , Glucosídeos/genética , Glucose/genética , Glucose/metabolismo , Engenharia Metabólica
12.
Environ Sci Technol ; 57(46): 17751-17761, 2023 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-36821784

RESUMO

In traditional soil heavy metal (HM) pollution assessment, spatial interpolation analysis is often carried out on the limited sampling points in the study area to get the overall status of heavy metal pollution. Unfortunately, in many machine learning spatial information enhancement algorithms, the additional spatial information introduced fails to reflect the hierarchical heterogeneity of the study area. Therefore, we designed hierarchical regionalization labels based on three interpolation techniques (inverse distance weight, ordinary kriging, and trend surface interpolation) as new spatial covariates for a machine learning (ML) model. It was demonstrated that regional spatial information improved the prediction performance of the model (R2 > 0.7). On the basis of the prediction results, the status of HM pollution in the Pearl River Delta (PRD) region was evaluated: cadmium (Cd) and copper (Cu) were the most serious pollutants in the PRD (the point overstandard rates are 18.77% and 12.95%, respectively). The analysis of index importance and bivariate local indicators of spatial association (LISA) shows that the key factors affecting the spatial distribution of heavy metals are geographical and climatic conditions [namely, altitude, humidity index, and normalized vegetation difference index (NDVI)] and some industrial activities (such as metal processing, printing and dyeing, and electronics industry). This study develops a novel approach to improve existing spatial interpolation techniques, which will enable more precise and scientific soil environmental management.


Assuntos
Metais Pesados , Poluentes do Solo , Rios , Monitoramento Ambiental/métodos , China , Solo , Medição de Risco
13.
Ecotoxicol Environ Saf ; 250: 114467, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36587414

RESUMO

Rapid economic development and industrialization may include environmentally harmful human activities that cause heavy-metal accumulation in soils, ultimately threatening the quality of the soil environment and human health. Therefore, accurate identification of pollution sources is an important weapon in efforts to control and prevent pollution. The self-organizing map (SOM) method is widely used in pollution source identification because of its capacity for visualization of high-dimensional data. The SOM ignores the graph structure relationship among chemical elements in soils; the SOM analysis of pollution sources has high uncertainty. Here, we propose a new analysis method, i.e., the graph convolutional self-organizing map (GCSOM), which uses a graph convolutional network (GCN) to extract the graph structure relationship among the chemical elements in soils, then performs data visualization using an SOM. We compared the performances of GCSOM and SOM, then assessed the pollution source characteristics of trace metal(loid)s (TMs, mostly heavy metals) in Jiangmen City using the GCSOM. Our experimental results showed that the GCSOM is superior to the SOM for identification of TM sources, while the TMs in the soil of Jiangmen originate from three main sources: agricultural activities (mainly in Taishan City, Jiangmen), traffic emissions (mainly in Xinhui and Pengjiang Districts), and industrial activities (mainly in Xinhui District). The risk assessment indicated that the risk of all TMs was within threshold.


Assuntos
Metais Pesados , Poluentes do Solo , Oligoelementos , Humanos , Solo/química , Monitoramento Ambiental/métodos , Poluentes do Solo/análise , China , Metais Pesados/análise , Oligoelementos/análise , Medição de Risco , Aprendizado de Máquina
14.
J Hazard Mater ; 445: 130451, 2023 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-36444807

RESUMO

Rare earth elements (REEs) have been increasingly diffused to the environment due to their extensive use and application in industries, agriculture, and high-tech devices, which have been regarded as emerge pollutants. However, the study concerning REEs in urban soils is still limited. Therefore, the objectives of this study were to investigate the potential source and risk of REEs in urban environment. We analyzed the concentration and distribution of REEs in urban park soils, and performed a combination of micro geochemical method and random forest method to characterize the pollution sources of REEs. The results showed that the ΣREE concentrations in Beijing urban park soils ranged from 117.19 to 198.09 mg/kg. Spatial distribution indicated that the high concentrations of REEs were mainly concentrated in the west of Beijing near an industrial area. The geochemical parameters, micro spherules and random forest results confirmed the anthropogenic pollution sources from industry and traffic. Risk assessment showed that the average daily doses of total REEs for children and adults were far below the reference threshold with values of 0.08 and 0.02 µg/kg/day, respectively. Our study has exhibited that though the reconstruction of parks from abandoned industrial sites showed an accumulation of REEs, the health risk of REEs for human beings are negligible.


Assuntos
Metais Terras Raras , Poluentes do Solo , Criança , Humanos , Solo/química , Pequim , Parques Recreativos , Metais Terras Raras/química , Agricultura , Monitoramento Ambiental/métodos , China , Poluentes do Solo/análise
15.
Environ Res ; 216(Pt 2): 114519, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36252833

RESUMO

Soil attributes and their environmental drivers exhibit different patterns in different geographical directions, along with distinct regional characteristics, which may have important effects on substance migration and transformation such as organic matter and soil elements or the environmental impacts of pollutants. Therefore, regional soil characteristics should be considered in the process of regionalization for environmental management. However, no comprehensive evaluation or systematic classification of the natural soil environment has been established for China. Here, we established an index system for natural soil environmental regionalization (NSER) by combining literature data obtained based on bibliometrics with the analytic hierarchy process (AHP). Based on the index system, we collected spatial distribution data for 14 indexes at the national scale. In addition, three clustering algorithms-self-organizing feature mapping (SOFM), fuzzy c-means (FCM) and k-means (KM)-were used to classify and define the natural soil environment. We imported four cluster validity indexes (CVI) to evaluate different models: Davies-Bouldin index (DB), Silhouette index (Sil) and Calinski-Harabasz index (CH) for FCM and KM, clustering quality index (CQI) for SOFM. Analysis and comparison of the results showed that when the number of clusters was 13, the FCM clustering algorithm achieved the optimal clustering results (DB = 1.16, Sil = 0.78, CH = 6.77 × 106), allowing the natural soil environment of China to be divided into 12 regions with distinct characteristics. Our study provides a set of comprehensive scientific research methods for regionalization research based on spatial data, it has important reference value for improving soil environmental management based on local conditions in China.


Assuntos
Algoritmos , Solo , Análise por Conglomerados , Geografia , China , Lógica Fuzzy
16.
Front Psychol ; 13: 1036579, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36524177

RESUMO

In recent years, knowledge hiding has become a hot topic in the field of organizational behavior because of its great harm. However, relevant studies have focused only on the negative interpersonal antecedents of knowledge hiding but neglected the inhibition effect of positive informal relationships on the behavior. To fill this gap, the current study develops a moderated mediation model to investigate how and when workplace friendship has a negative impact on knowledge hiding. Drawing on social exchange theory (SET), we propose that workplace friendship inhibits knowledge hiding through the mediating role of employee well-being, with the Perception of Chaxu climate acting as a boundary condition. Using data from a two-wave time-lagged survey of 279 employees in China, the results show that workplace friendship has a negative impact on knowledge hiding behavior. Specifically, workplace friendship inhibits knowledge hiding by satisfied employee well-being, i.e., workplace friendship has a positive impact on employee well-being, while employee well-being has a negative impact on knowledge hiding. Perception of Chaxu Climate moderates the indirect effect, as the level of employee's Perception of Chaxu climate rises, the direct effect of workplace friendship on employee well-being is stronger, so as the indirect effect of workplace friendship on knowledge hiding. This article explores the mechanisms affecting employee knowledge hiding from a new interpersonal perspective of workplace friendship. It is enlightened that firms should pay attention to the management of workplace friendship, provide employee with opportunities to establish workplace friendship while providing proper guidance on the direction of workplace friendship and improving the quality of it, in order to promote employees' happiness perception and organizational knowledge management ability.

17.
Environ Sci Technol ; 56(22): 16189-16199, 2022 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-36214785

RESUMO

Volatile organic amines are a category of typical volatile organic compounds (VOCs) extensively presented in industrial exhausts causing serious harm to the atmospheric environment and human health. Monometallic Pd and Cu-based catalysts are commonly adopted for catalytic destruction of hazardous organic amines, but their applications are greatly limited by the inevitable production of toxic amide and NOx byproducts and inferior low-temperature activity. Here, a CuO/Pd@SiO2 core-shell-structured catalyst with diverse functionalized active sites was creatively developed, which realized the total decomposition of n-butylamine at 260 °C with a CO2 yield and N2 selectivity reaching up to 100% and 98.3%, respectively (obviously better than those of Pd@SiO2 and CuO/SiO2), owing to the synergy of isolated Pd and Cu sites in independent mineralization of n-butylamine and generation of N2, respectively. The formation of amide and short-chain aliphatic hydrocarbon intermediates via C-C bond cleavage tended to occur over Pd sites, while the C-N bond was prone to breakage over Cu sites, generating NH2· species and long free-N chain intermediates at low temperatures, avoiding the production of hazardous amide and NOx. The SiO2 channel collapse and H+ site production resulted in the formation of N2O via suppressing NH2· diffusion. This work provides critical guidance for a rational fabrication of catalysts with high activity and N2 selectivity for environmentally friendly destruction of nitrogen-containing VOCs.


Assuntos
Butilaminas , Dióxido de Silício , Humanos , Dióxido de Silício/química , Domínio Catalítico , Amidas
18.
Environ Res ; 215(Pt 1): 114178, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36087773

RESUMO

In an era of unprecedented human influence, different human activities have different degrees of impact on specific bacteria, resulting in the regional biological homogenization of soil bacteria. However, the contribution of the impact that a large number of anthropogenic activities on bacteria remains unknown. Here, by high-throughput amplicon sequencing, we characterized the composition, diversity and influencing factors of soil microbes in Beijing urban parks at geographic space and park management aspect. It is the first time to quantify and compare the importance of the impact of up to 15 human activities on soil bacterial communities. The results show that the dominant bacterial phyla in Beijing urban parks were Actinobacteria, Proteobacteria, Acidobacteria and Chloroflexi. The environmental management of different park types, as well as the land use history and development conditions of different regions, had significant differences in soil bacterial community structure. Soil bacteria in urban parks were disturbed by direct human interference far more than natural causes. The most important factors were related to the number of tourists and residents, industrial production and land use patterns. These factors may also be related to the abundance of unknown bacteria in urban parks. This also directly shows that human activities have a non-negligible impact on soil bacteria. The ways in which different human activities brought by global urbanization and their impacting mechanisms are used should be the starting point of future research.


Assuntos
Parques Recreativos , Solo , Bactérias/genética , Pequim , Humanos , Solo/química , Microbiologia do Solo
19.
J Environ Manage ; 319: 115685, 2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-35816963

RESUMO

Contaminated sites are a main cause of urban soil problems and have led to increasing pollution and public risk in China as a result of the rapid growth of industrial and urban land use. Because land pollution involves extensive multi-source heterogeneous information, identifying the risk of urban soil pollution efficiently and predicting pollution-related events are important for urban environmental management. Knowledge graphs (KGs) have unique advantages in dealing with massive amounts of information. This study attempts to construct a KG of contaminated sites in South China to explore its feasibility and effectiveness in urban soil environmental management. The results demonstrate that KGs have a favorable effect in information retrieval, knowledge reasoning, and visualization. Studied cases in this article demonstrate that the KG model can achieve many functions, including the display of global information of polluted sites, and discovery of regional distribution of characteristic pollutants and main pollutants of specific industries, based on special query syntax. However, this approach is limited by some technical difficulties, such as knowledge mining of natural resources, which must be overcome in future studies to improve the operability of KG technologies.


Assuntos
Poluentes Ambientais , Metais Pesados , Poluentes do Solo , China , Monitoramento Ambiental/métodos , Poluição Ambiental/análise , Metais Pesados/análise , Reconhecimento Automatizado de Padrão , Medição de Risco , Solo , Poluentes do Solo/análise
20.
Environ Res ; 212(Pt C): 113384, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35561823

RESUMO

Urban parks are important places that allow urban residents to experience nature but are also associated with the risk of exposure to contaminated soil. Therefore, it is necessary to establish appropriate soil environment criteria (SEC) to manage park soil quality. Studies on the demographic characteristics and behavioral patterns of urban park visitors are helpful for the selection of sensitive receptors and the determination of parameters in the establishment of SEC. This study explored the park visitors' demographic characteristics and behavioral patterns, and applied the results to derive SEC. Eighty-six parks in Beijing were selected, and mobile phone data were obtained to analysis the demographic characteristics and residence time of the visitors. Kruskal-Wallis test, kernel density estimation and random forest model were used for data analysis. The CLEA model was used to derive SEC. The results showed that the demographic characteristics and behavioral patterns of visitors in different types of parks were quite different. Parks were mostly used by males and visitors aged 31-45. Most visitors stayed in the park for 1-2 h, and the distance from a given visitor's home to the park was the most important factor affecting stay time. Then, several parameters such as the parameters related to the receptors and occupation period were optimized, and the SEC of sensitive parks and non-sensitive parks were derived. Exposure frequency may be the main reason for the difference of SEC between the two types of parks. The SECs of sensitive parks were higher than the soil screening values (SSVs) for class 1 land in GB36600-2018, indicating that the current SSVs for some parks may be too conservative. This study provides a reference for the formulation and revision of soil environmental standards for park land, and suggests strengthening research on human behavioral patterns.


Assuntos
Parques Recreativos , Solo , Pequim , China , Poluição Ambiental , Humanos , Masculino , Recreação
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