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1.
Se Pu ; 42(8): 740-748, 2024 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-39086242

RESUMO

Perfluorinated and polyfluoroalkyl substances (PFASs) are compounds characterized by at least one perfluorinated carbon atom in an alkyl chain linked to side-chain groups. Owing to their unique chemical properties, these compounds are widely used in industrial production and daily life. However, owing to anthropogenic activities, sewage discharge, surface runoff, and atmospheric deposition, PFASs have gradually infiltrated the environment and aquatic resources. With their gradual accumulation in environmental waters, PFASs have been detected in fishes and several fish-feeding species, suggesting that they are bioconcentrated and even amplified in aquatic organisms. PFASs exhibit high intestinal absorption efficiencies, and they bioaccumulate at higher trophic levels in the food chain. They can be bioconcentrated in the human body via food (e. g., fish) and thus threaten human health. Therefore, establishing an efficient analytical technique for use in analyzing PFASs in typical fish samples and providing technical support for the safety regulation and risk assessment of fish products is necessary. In this study, by combining solvent extraction and magnetic dispersion-solid phase extraction (d-SPE), an improved QuEChERS method with ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was developed for the determination of 13 PFASs in fish samples. Fe3O4-TiO2 can be used as an ideal adsorbent in the removal of sample matrix interference and a separation medium for the rapid encapsulation of other solids to be isolated from the solution. Based on the matrix characteristics of the fish products and structural properties of the target PFASs, Fe3O4-TiO2 and N-propyl ethylenediamine (PSA) were employed as adsorbents in dispersive purification. The internal standard method was used in the quantitative analyses of the PFASs. To optimize the sample pretreatment conditions of analyzing PFASs, the selection of the extraction solvent and amounts of Fe3O4-TiO2 and PSA were optimized. Several PFASs contain acidic groups that are non-dissociated in acidic environments, thus favoring their entry into the organic phase. In addition, acidified acetonitrile can denature and precipitate the proteins within the sample matrix, facilitating their removal. Finally, 2% formic acid acetonitrile was used as the extraction solvent, and 20 mg Fe3O4-TiO2, 20 mg PSA and 120 mg anhydrous MgSO4 were used as purification adsorbents. Under the optimized conditions, the developed method exhibited an excellent linearity (R≥0.9973) in the range of 0.01-50 µg/L, and the limits of detection (LODs) and quantification (LOQs) ranged from 0.001-0.023 and 0.003-0.078 µg/L, respectively. The recoveries of the 13 PFASs at low, medium, and high spiked levels (0.5, 10, and 100 µg/kg) were 78.1%-118%, with the intra- and inter-day precisions of 0.2%-11.1% and 0.8%-8.7%, respectively. This method was applied in analyzing real samples, and PFASs including perfluorooctanesulfonic acid, perfluorooctanoic acid, perfluoroundecanoic acid, perfluorododecanoic acid, and perfluorotridecanoic acid, were detected in all 11 samples evaluated. This method is simple, sensitive, and suitable for use in analyzing PFASs in fish samples.


Assuntos
Peixes , Fluorocarbonos , Contaminação de Alimentos , Espectrometria de Massas em Tandem , Espectrometria de Massas em Tandem/métodos , Fluorocarbonos/análise , Animais , Cromatografia Líquida de Alta Pressão , Contaminação de Alimentos/análise , Caprilatos/análise , Ácidos Alcanossulfônicos/análise
2.
Glob Chang Biol ; 30(5): e17295, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38804108

RESUMO

Plant-soil biodiversity interactions are fundamental for the functioning of terrestrial ecosystems. Yet, the existence of a set of globally distributed topsoil microbial and small invertebrate organisms consistently associated with land plants (i.e., their consistent soil-borne microbiome), together with the environmental preferences and functional capabilities of these organisms, remains unknown. We conducted a standardized field survey under 150 species of land plants, including 58 species of bryophytes and 92 of vascular plants, across 124 locations from all continents. We found that, despite the immense biodiversity of soil organisms, the land plants evaluated only shared a small fraction (less than 1%) of all microbial and invertebrate taxa that were present across contrasting climatic and soil conditions and vegetation types. These consistent taxa were dominated by generalist decomposers and phagotrophs and their presence was positively correlated with the abundance of functional genes linked to mineralization. Finally, we showed that crossing environmental thresholds in aridity (aridity index of 0.65, i.e., the transition from mesic to dry ecosystems), soil pH (5.5; i.e., the transition from acidic to strongly acidic soils), and carbon (less than 2%, the lower limit of fertile soils) can result in drastic disruptions in the associations between land plants and soil organisms, with potential implications for the delivery of soil ecosystem processes under ongoing global environmental change.


Assuntos
Embriófitas , Microbiota , Microbiologia do Solo , Biodiversidade , Solo/química
3.
Zhongguo Zhong Yao Za Zhi ; 49(10): 2728-2733, 2024 May.
Artigo em Chinês | MEDLINE | ID: mdl-38812173

RESUMO

A two-step synthetic process of bromination and cross-coupling with aristololactam Ⅰ as raw material was successfully developed. Three aristolactam Ⅰ-deoxyriboside adducts, namely AAⅠ-dA, AAⅠ-dG, and AAⅠ-dC were obtained after a sequential procedure of impurity removal and purification in four different solvents. The yield of the two-step reaction can reach 90%, and the purity of the product is more than 98%, which can meet the requirements of qualitative and quantitative analyses as traditional Chinese medicine chemical reference products. The process has been proven to have good repeatability and scalability, and it features a concise preparation procedure, efficient purification, and high yield and purity, requiring no chromatographic separation. Compared with pre-vious methods, the newly developed process has significant advantages and is suitable for the preparation of chemical reference products of aristolactam Ⅰ-deoxyriboside adducts. This process provides technical support for the preparation of reference products of aristolactam Ⅰ-deoxyriboside adducts and a solid material basis for the related toxicological research.


Assuntos
Medicamentos de Ervas Chinesas , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/normas , Medicamentos de Ervas Chinesas/análise , Padrões de Referência , Cromatografia Líquida de Alta Pressão/métodos
4.
Nat Food ; 5(4): 301-311, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38605129

RESUMO

Contamination of rice by the potent neurotoxin methylmercury (MeHg) originates from microbe-mediated Hg methylation in soils. However, the high diversity of Hg methylating microorganisms in soils hinders the prediction of MeHg formation and challenges the mitigation of MeHg bioaccumulation via regulating soil microbiomes. Here we explored the roles of various cropland microbial communities in MeHg formation in the potentials leading to MeHg accumulation in rice and reveal that Geobacteraceae are the key predictors of MeHg bioaccumulation in paddy soil systems. We characterized Hg methylating microorganisms from 67 cropland ecosystems across 3,600 latitudinal kilometres. The simulations of a rice-paddy biogeochemical model show that MeHg accumulation in rice is 1.3-1.7-fold more sensitive to changes in the relative abundance of Geobacteraceae compared to Hg input, which is recognized as the primary parameter in controlling MeHg exposure. These findings open up a window to predict MeHg formation and accumulation in human food webs, enabling more efficient mitigation of risks to human health through regulations of key soil microbiomes.


Assuntos
Compostos de Metilmercúrio , Oryza , Microbiologia do Solo , Poluentes do Solo , Bioacumulação , Compostos de Metilmercúrio/metabolismo , Compostos de Metilmercúrio/análise , Microbiota/efeitos dos fármacos , Oryza/metabolismo , Oryza/química , Oryza/microbiologia , Solo/química , Poluentes do Solo/metabolismo , Poluentes do Solo/análise
5.
Zool Res ; 45(2): 367-380, 2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38485506

RESUMO

Osteoporosis is a prevalent metabolic bone disease. While drug therapy is essential to prevent bone loss in osteoporotic patients, current treatments are limited by side effects and high costs, necessitating the development of more effective and safer targeted therapies. Utilizing a zebrafish ( Danio rerio) larval model of osteoporosis, we explored the influence of the metabolite spermine on bone homeostasis. Results showed that spermine exhibited dual activity in osteoporotic zebrafish larvae by increasing bone formation and decreasing bone resorption. Spermine not only demonstrated excellent biosafety but also mitigated prednisolone-induced embryonic neurotoxicity and cardiotoxicity. Notably, spermine showcased protective attributes in the nervous systems of both zebrafish embryos and larvae. At the molecular level, Rac1 was identified as playing a pivotal role in mediating the anti-osteoporotic effects of spermine, with P53 potentially acting downstream of Rac1. These findings were confirmed using mouse ( Mus musculus) models, in which spermine not only ameliorated osteoporosis but also promoted bone formation and mineralization under healthy conditions, suggesting strong potential as a bone-strengthening agent. This study underscores the beneficial role of spermine in osteoporotic bone homeostasis and skeletal system development, highlighting pivotal molecular mediators. Given their efficacy and safety, human endogenous metabolites like spermine are promising candidates for new anti-osteoporotic drug development and daily bone-fortifying agents.


Assuntos
Osteoporose , Doenças dos Roedores , Humanos , Camundongos , Animais , Peixe-Zebra , Espermina/uso terapêutico , Osteoporose/tratamento farmacológico , Osteoporose/metabolismo , Osteoporose/prevenção & controle , Osteoporose/veterinária , Prednisolona/efeitos adversos , Glucocorticoides , Doenças dos Roedores/induzido quimicamente , Doenças dos Roedores/tratamento farmacológico
6.
J Colloid Interface Sci ; 662: 870-882, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38382371

RESUMO

The extensive examination of hexagonal molybdenum carbide (ß-Mo2C) as a non-noble cocatalyst in the realm of photocatalytic H2 evolution is predominantly motivated by its exceptional capacity to adsorb H+ ions akin to Pt and its advantageous conductivity characteristics. However, the H2 evolution rate of photocatalysts modified with ß-Mo2C is limited as a result of their comparatively low ability to release H through desorption. Therefore, a facile method was employed to synthesize carbon intercalated dual phase molybdenum carbide (MC@C) quantum dots (ca. 3.13 nm) containing both α-MoC and ß-Mo2C decorated on g-C3N4 (gCN). The synthesis process involved a simple and efficient combination of sonication-assisted self-assembly and calcination techniques. 3-MC@C/gCN exhibited the highest efficiency in generating H2, with a rate of 4078 µmol g-1h-1 under 4 h simulated sunlight irradiation, which is 13 times higher than pristine gCN. Furthermore, from the cycle test, 3-MC@C/gCN showcased exceptional photochemical stability of 65 h, as it maintained a H2 evolution rate of 40 mmol g-1h-1. The heightened level of activity observed in the 3-MC@C/gCN system can be ascribed to the synergistic effects of MoC-Mo2C that arise due to the existence of a carbon layer. The presence of a carbon layer enhanced the transmission of photoinduced electrons, while the MoC-Mo2C@C composite served as active sites, thereby facilitating the H2 production reaction of gCN. The present study introduces a potentially paradigm-shifting concept pertaining to the exploration of novel Mo-based cocatalysts with the aim of augmenting the efficacy of photocatalytic H2 production.

8.
Environ Pollut ; 337: 122603, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37748640

RESUMO

The neurotoxic methylmercury (MeHg) in paddy soils can accumulate in rice grains. Microbial demethylation is an important pathway of MeHg degradation in soil, but the effect of soil type on microbial degradation of MeHg remains unclear. Therefore, we investigated MeHg degradation in eight typical paddy soils and analyzed the associations between soil physiochemical properties and microbial degradation efficiencies of MeHg. Results showed that MeHg was significantly degraded in unsterilized paddy soils, and the microbial degradation efficiency ranged from 10.8% to 64.6% after a 30-day incubation. The high microbial degradation efficiency of MeHg was observed in the soils with high levels of clay content, whereas relatively low degradation efficiency was found in the red paddy soils. We identified that Paenibacillaceae was the most important microbial predictor of MeHg degradation and was positively correlated with the degradation efficiency in the soils. The abundances of these microbial taxa associated with MeHg degradation were positively correlated with clay content. In addition, Eh, pH, and SOC could influence microbial degradation of MeHg by regulating certain microbial communities. Our results indicate that soil type is crucial in driving MeHg degradation, which has important implications for the mitigation of MeHg pollution in various croplands.


Assuntos
Mercúrio , Compostos de Metilmercúrio , Oryza , Poluentes do Solo , Compostos de Metilmercúrio/metabolismo , Mercúrio/análise , Solo/química , Argila , Poluentes do Solo/análise , Oryza/metabolismo
9.
BMC Musculoskelet Disord ; 24(1): 683, 2023 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-37644473

RESUMO

BACKGROUND: Alignment is indispensable for the foot and ankle function, especially in the hindfoot alignment. In the preoperative planning of patients with varus or valgus deformity, the precise measurement of the hindfoot alignment is important. A new method of photographing and measuring hindfoot alignment based on X-ray was proposed in this study, and it was applied in the assessment of flatfoot. METHODS: This study included 28 patients (40 feet) with flatfeet and 20 volunteers (40 feet) from January to December 2018. The hindfoot alignment shooting stand independently designed by our department was used to take hindfoot alignment X-rays at 10 degree, 15 degree, 20 degree, 25 degree, and 30 degree. We measured the modified tibio-hindfoot angle (THA) at the standard hindfoot aligment position (shooting at 20 degree) and evaluated consistency with the van Dijk method and the modified van Dijk method. In addition, we observed the visibility of the tibiotalar joint space from all imaging data at five projection angles and evaluated the consistency of the modified THA method at different projection angles. The angle of hindfoot valgus of flatfoot patients was measured using the modified THA method. RESULTS: The mean THA in the standard hindfoot aligment view in normal people was significantly different among the three evaluation methods (P < .001). The results from the modified THA method were significantly larger than those from the Van Dijk method (P < .001) and modified Van Dijk method (P < .001). There was no significant difference between the results of the modified THA method and the weightbearing CT (P = .605), and the intra- and intergroup consistency were the highest in the modified THA group. The tibiotalar space in the normal group was visible in all cases at 10 degree, 15 degree, and 20 degree; visible in some cases at 25 degree; and not visible in all cases at 30 degree. In the flatfoot group, the tibiotalar space was visible in all cases at 10 degree, visible in some cases at 15 degree and 20 degree, and not visible in all cases at 25 degree and 30 degree. In the normal group, the modified THA was 4.84 ± 1.81 degree at 10 degree, 4.96 ± 1.77 degree at 15 degree, and 4.94 ± 2.04 degree at 20 degree. No significant differences were found among the three groups (P = .616). In the flatfoot group, the modified THA of 18 feet, which was visible at 10 degree, 15 degree and 20 degree, was 13.58 ± 3.57 degree at 10 degree, 13.62 ± 3.83 degree at 15 degree and 13.38 ± 4.06 degree at 20 degree. There were no significant differences among the three groups (P = .425). CONCLUSIONS: The modified THA evaluation method is simple to use and has high inter- and intragroup consistency. It can be used to evaluate hindfoot alignment. For patients with flatfeet, the 10 degree position view and modified THA measurement can be used to evaluate hindfoot valgus.


Assuntos
Pé Chato , Humanos , Pé Chato/diagnóstico por imagem , , Radiografia , Extremidade Inferior , Articulação do Tornozelo
11.
Se Pu ; 41(4): 330-338, 2023 Apr.
Artigo em Chinês | MEDLINE | ID: mdl-37005920

RESUMO

Eight well-known herbals in Zhejiang Province, Zhebawei, are commonly used as traditional Chinese herbal medicines owing to their rich active ingredients. However, the unavoidable use of pesticides during agricultural production has led to pesticide residue problems in these herbs. In this study, a simple, rapid, and accurate method was established to determine 22 triazole pesticide residues in Zhebawei. An improved QuEChERS method was used for sample pretreatment, and Rhizoma Atractylodis Macrocephalae was used as a representative sample. The sample was extracted with acetonitrile to eliminate some polar and nonpolar compounds, pigments, and other impurities, and the purification effects of multiwalled carbon nanotubes (MWCNTs), amino-modified multiwalled carbon nanotubes (MWCNTs-NH2), carboxylated multiwalled carbon nanotubes (MWCNTs-COOH), crosslinked polyvinylpyrrolidone (PVPP), zirconium dioxide (ZrO2), 3-(N,N-diethylamino)-propyltrimethoxysilane (PSA), octadecyl (C18), and graphitized carbon black (GCB) were compared. MWCNTs-COOH and C18 were selected as the purification adsorbents, and their dosages were systematically optimized. The combination of 10 mg of MWCNTs-COOH and 20 mg of C18 was eventually selected as the purification adsorbents. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used for analysis, and box graphs were plotted to present the dispersion of each group of recoveries, thus enabling the identification of the data outliers, dispersion distribution, and data symmetry. The established method was systematically verified and showed good linearity over the concentration range of 1-200 µg/L (except for bromuconazole, epoxiconazole, and etaconazole) with correlation coefficients >0.99. The average recoveries of the 22 pesticides at spiked levels of 10, 20, 100, and 200 µg/kg were in the range of 77.0%-115% with relative standard deviations (RSDs) <9.4%. The limits of detection and quantification were 1-2.5 µg/kg and 10-20 µg/kg, respectively. The applicability of the developed method to other herbals was investigated at 100 µg/kg, and the average recoveries of the target pesticides in different matrices ranged from 76.4% to 123% with RSDs <12.2%. Finally, the method established was used to detect triazole pesticide residues in 30 actual Zhebawei samples. The results showed that triazole pesticides were present in Bulbus Fritillariae Thunbergii and Dendranthema Morifolium. Difenoconazole was detected in Bulbus Fritillariae Thunbergii at contents ranging from 41.4 µg/kg to 110 µg/kg, while difenoconazole, myclobutanil, triadimenol and propiconazole were detected in Dendranthema Morifolium at contents ranging from 16.1 µg/kg to 250 µg/kg. The established method can meet the requirements for the accurate quantitative analysis of triazole fungicides in Zhebawei.


Assuntos
Nanotubos de Carbono , Resíduos de Praguicidas , Praguicidas , Cromatografia Líquida , Resíduos de Praguicidas/análise , Nanotubos de Carbono/análise , Nanotubos de Carbono/química , Espectrometria de Massas em Tandem , Praguicidas/análise , Triazóis/análise , Extratos Vegetais/análise
12.
Nanoscale ; 15(14): 6536-6562, 2023 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-36942445

RESUMO

The electro/photocatalytic CO2 reduction reaction (CO2RR) is a long-term avenue toward synthesizing renewable fuels and value-added chemicals, as well as addressing the global energy crisis and environmental challenges. As a result, current research studies have focused on investigating new materials and implementing numerous fabrication approaches to increase the catalytic performances of electro/photocatalysts toward the CO2RR. MXenes, also known as 2D transition metal carbides, nitrides, and carbonitrides, are intriguing materials with outstanding traits. Since their discovery in 2011, there has been a flurry of interest in MXenes in electrocatalysis and photocatalysis, owing to their several benefits, including high mechanical strength, tunable structure, surface functionality, high specific surface area, and remarkable electrical conductivity. Herein, this review serves as a milestone for the most recent development of MXene-based catalysts for the electrocatalytic and photocatalytic CO2RR. The overall structure of MXenes is described, followed by a summary of several synthesis pathways classified as top-down and bottom-up approaches, including HF-etching, in situ HF-formation, electrochemical etching, and halogen etching. Additionally, the state-of-the-art development in the field of both the electrocatalytic and photocatalytic CO2RR is systematically reviewed. Surface termination modulation and heterostructure engineering of MXene-based electro/photocatalysts, and insights into the reaction mechanism for the comprehension of the structure-performance relationship from the CO2RR via density functional theory (DFT) have been underlined toward activity enhancement. Finally, imperative issues together with future perspectives associated with MXene-based electro/photocatalysts are proposed.

13.
Graefes Arch Clin Exp Ophthalmol ; 261(8): 2327-2334, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-36859735

RESUMO

PURPOSE: This study aims to investigate the applicability of lower lid margin thickness (LLMT) measurements in adults with and without meibomian gland dysfunction (MGD) by optical coherence tomography (OCT) and keratograph. METHODS: This is a cross-sectional, observational study. A hundred and eight volunteers aged 20 to 79, including 68 MGD patients and 40 normal subjects, were recruited. Using OCT and keratograph to measure the LLMT from the posterior lash line to anterior edge or outer edge of the tear meniscus was separately performed two times by the same person. RESULTS: The mean age of normal and MGD subjects was 50.5 ± 14.2 years and 55.8 ± 15.5 years, respectively. The LLMT with OCT and keratograph in MGD patients was significantly greater than that in normal subjects (1.06 ± 0.27 and 1.03 ± 0.25 mm vs. 0.90 ± 0.20 and 0.86 ± 0.16 mm, respectively). In both normal and MGD subjects, the tear meniscus height and LLMT with OCT were both greater than that with keratograph (P < 0.05), and intraclass correlation coefficient (ICC) demonstrated a good agreement in the LLMT measurements between two devices (ICC = 0.83 and 0.79, respectively). Additionally, the LLMT in MGD patients was appeared to be positively correlated with meiboscore (rs = 0.37, P = 0.002). CONCLUSIONS: The OCT and keratograph were two reliable tools in the LLMT measurements, which may have potential applications for diagnosis and evaluation of MGD. Furthermore, we found that the LLMT measured by OCT was greater than that measured by keratograph.


Assuntos
Síndromes do Olho Seco , Disfunção da Glândula Tarsal , Adulto , Humanos , Pessoa de Meia-Idade , Tomografia de Coerência Óptica , Síndromes do Olho Seco/diagnóstico , Lágrimas , Estudos Transversais , Glândulas Tarsais
14.
Nat Commun ; 14(1): 1706, 2023 03 27.
Artigo em Inglês | MEDLINE | ID: mdl-36973286

RESUMO

Soil contamination is one of the main threats to ecosystem health and sustainability. Yet little is known about the extent to which soil contaminants differ between urban greenspaces and natural ecosystems. Here we show that urban greenspaces and adjacent natural areas (i.e., natural/semi-natural ecosystems) shared similar levels of multiple soil contaminants (metal(loid)s, pesticides, microplastics, and antibiotic resistance genes) across the globe. We reveal that human influence explained many forms of soil contamination worldwide. Socio-economic factors were integral to explaining the occurrence of soil contaminants worldwide. We further show that increased levels of multiple soil contaminants were linked with changes in microbial traits including genes associated with environmental stress resistance, nutrient cycling, and pathogenesis. Taken together, our work demonstrates that human-driven soil contamination in nearby natural areas mirrors that in urban greenspaces globally, and highlights that soil contaminants have the potential to cause dire consequences for ecosystem sustainability and human wellbeing.


Assuntos
Cidades , Ecossistema , Internacionalidade , Parques Recreativos , Poluentes do Solo , Solo , Microbiota , Fatores Socioeconômicos , Solo/química , Microbiologia do Solo , Poluentes do Solo/análise , Poluentes do Solo/química , Plásticos
15.
Environ Sci Technol ; 57(14): 5988-5998, 2023 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-36995950

RESUMO

Methylmercury (MeHg) is a potent neurotoxin and has great adverse health impacts on humans. Organisms and sunlight-mediated demethylation are well-known detoxification pathways of MeHg, yet whether abiotic environmental components contribute to MeHg degradation remains poorly known. Here, we report that MeHg can be degraded by trivalent manganese (Mn(III)), a naturally occurring and widespread oxidant. We found that 28 ± 4% MeHg could be degraded by Mn(III) located on synthesized Mn dioxide (MnO2-x) surfaces during the reaction of 0.91 µg·L-1 MeHg and 5 g·L-1 mineral at an initial pH of 6.0 for 12 h in 10 mM NaNO3 at 25 °C. The presence of low-molecular-weight organic acids (e.g., oxalate and citrate) substantially enhances MeHg degradation by MnO2-x via the formation of soluble Mn(III)-ligand complexes, leading to the cleavage of the carbon-Hg bond. MeHg can also be degraded by reactions with Mn(III)-pyrophosphate complexes, with apparent degradation rate constants comparable to those by biotic and photolytic degradation. Thiol ligands (cysteine and glutathione) show negligible effects on MeHg demethylation by Mn(III). This research demonstrates potential roles of Mn(III) in degrading MeHg in natural environments, which may be further explored for remediating heavily polluted soils and engineered systems containing MeHg.


Assuntos
Mercúrio , Compostos de Metilmercúrio , Humanos , Manganês/química , Compostos de Metilmercúrio/metabolismo , Oxidantes/química , Cisteína
16.
ISME J ; 17(3): 478-485, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36639538

RESUMO

Methylmercury (MeHg) is a potent neurotoxin that bioaccumulates along food chains. The conversion of MeHg from mercury (Hg) is mediated by a variety of anaerobic microorganisms carrying hgcAB genes. Mangrove sediments are potential hotspots of microbial Hg methylation; however, the microorganisms responsible for Hg methylation are poorly understood. Here, we conducted metagenomic and metatranscriptomic analyses to investigate the diversity and distribution of putative microbial Hg-methylators in mangrove ecosystems. The highest hgcA abundance and expression occurred in surface sediments in Shenzhen, where the highest MeHg concentration was also observed. We reconstructed 157 metagenome-assembled genomes (MAGs) carrying hgcA and identified several putative novel Hg-methylators, including one Asgard archaea (Lokiarchaeota). Further analysis of MAGs revealed that Deltaproteobacteria, Euryarchaeota, Bacteroidetes, Chloroflexi, and Lokiarchaeota were the most abundant and active Hg-methylating groups, implying their crucial role in MeHg production. By screening publicly available MAGs, 104 additional Asgard MAGs carrying hgcA genes were identified from a wide range of coast, marine, permafrost, and lake sediments. Protein homology modelling predicts that Lokiarchaeota HgcAB proteins contained the highly conserved amino acid sequences and folding structures required for Hg methylation. Phylogenetic tree revealed that hgcA genes from Asgard clustered with fused hgcAB genes, indicating a transitional stage of Asgard hgcA genes. Our findings thus suggest that Asgard archaea are potential novel Hg-methylating microorganisms and play an important role in hgcA evolution.


Assuntos
Mercúrio , Compostos de Metilmercúrio , Mercúrio/metabolismo , Archaea/genética , Archaea/metabolismo , Ecossistema , Metilação , Filogenia , Compostos de Metilmercúrio/metabolismo , Sedimentos Geológicos/microbiologia
17.
Nat Ecol Evol ; 7(1): 113-126, 2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36631668

RESUMO

While the contribution of biodiversity to supporting multiple ecosystem functions is well established in natural ecosystems, the relationship of the above- and below-ground diversity with ecosystem multifunctionality remains virtually unknown in urban greenspaces. Here we conducted a standardized survey of urban greenspaces from 56 municipalities across six continents, aiming to investigate the relationships of plant and soil biodiversity (diversity of bacteria, fungi, protists and invertebrates, and metagenomics-based functional diversity) with 18 surrogates of ecosystem functions from nine ecosystem services. We found that soil biodiversity across biomes was significantly and positively correlated with multiple dimensions of ecosystem functions, and contributed to key ecosystem services such as microbially driven carbon pools, organic matter decomposition, plant productivity, nutrient cycling, water regulation, plant-soil mutualism, plant pathogen control and antibiotic resistance regulation. Plant diversity only indirectly influenced multifunctionality in urban greenspaces via changes in soil conditions that were associated with soil biodiversity. These findings were maintained after controlling for climate, spatial context, soil properties, vegetation and management practices. This study provides solid evidence that conserving soil biodiversity in urban greenspaces is key to supporting multiple dimensions of ecosystem functioning, which is critical for the sustainability of urban ecosystems and human wellbeing.


Assuntos
Ecossistema , Solo , Humanos , Parques Recreativos , Biodiversidade , Plantas
18.
J Anesth ; 37(2): 177-185, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36462032

RESUMO

PURPOSE: Anxiety and pain commonly occur during nerve block, we aimed to investigate the sedation efficacy of different doses of remimazolam with sufentanil in young and elderly patients. METHODS: In this randomized trial, patients aged 18-85 years who underwent nerve block was enrolled. All patients received sufentanil 0.08 µg/kg for analgesia. Young patients (age < 65 years) were randomized into the control group (Group C, 0.9% saline), medium-dose remimazolam (Group M, 0.06 mg/kg) and high-dose remimazolam group (Group H, 0.08 mg/kg). Elderly patients (age ≥ 65 years) were randomized into the Group C, low-dose remimazolam group (Group L, 0.04 mg/kg) and Group M. Primary outcome was the success rate of procedure sedation. Respiratory depression and hypoxia were the interested safety outcomes. RESULTS: Ninety young and 114 elderly patients were enrolled, respectively. In comparison with Groups C and M, young patients in Group H had the highest success rate of procedure sedation (80.0 vs. 73.3 vs. 43.3%, P = 0.006). Elderly patients in Groups M and L had similar success rates of procedure sedation, which were significantly higher than that in Group C (78.9 vs. 78.9 vs. 50.0%, P = 0.007). In elderly patients, the incidence of respiratory depression and hypoxia tended to be higher in Group M than those in Groups L and C (both P < 0.001). CONCLUSION: Remimazolam 0.08 mg/kg provided the best sedation efficacy in young patients while remimazolam 0.04 mg/kg with the trend of less respiratory adverse events was more optimal for elderly patients. TRIAL REGISTRATION: http://www.chictr.org.cn/showproj.aspx?proj=122016 .


Assuntos
Bloqueio Nervoso , Insuficiência Respiratória , Idoso , Humanos , Sufentanil/efeitos adversos , Hipnóticos e Sedativos/efeitos adversos , Método Duplo-Cego , Benzodiazepinas/efeitos adversos , Dor/induzido quimicamente
19.
Food Chem ; 402: 134470, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36303383

RESUMO

In this study, after proposing a method for the preparation of selenium nanoparticles (Se NPs) with stable properties using zein, the physico-chemical properties of zein-Se NPs were tested. The complex structure of zein-Se NPs was deduced by SEM, and the binding mechanism was determined by FT-IR and XPS. The particle size of zein-Se NPs could be regulated from 11.4 ± 0.1 nm to 138.7 ± 0.9 nm under different preparation parameters, the reason for the change in particle size had been speculated. The pH responsiveness and 30-day storage stability of the zein-Se NPs were discussed. The zein-Se NPs still had strong DPPH radical scavenging activity after heat treatment. The zein-Se NPs were cell-friendly and was able to effectively protect cells from H2O2-induced cell-death. This study performed an extensive determination of the underlying physico-chemical properties of zein-Se NPs, we anticipate this approach will open up new possibilities in using natural material to stabilize Se NPs.


Assuntos
Nanopartículas , Selênio , Zeína , Zeína/química , Selênio/farmacologia , Selênio/química , Peróxido de Hidrogênio , Espectroscopia de Infravermelho com Transformada de Fourier , Nanopartículas/química , Tamanho da Partícula
20.
Front Surg ; 9: 1023551, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36406366

RESUMO

Pregnancy-related acute myocardial infarction (PAMI) is rare but life-threatening. The incidence of PAMI is growing over time for multiple reasons, and the management of parturients with acute myocardial infarction is challenging in terms of diagnosis and treatment. To date, there are still no clear guidelines on the best practice for PAMI. We present a case of a 41-year-old woman with PAMI at 31 weeks of pregnancy. Through multidisciplinary collaboration, successful outcomes were achieved for both the mother and fetus.

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