Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 3.476
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Mol Cell ; 81(23): 4876-4890.e7, 2021 12 02.
Artigo em Inglês | MEDLINE | ID: mdl-34739871

RESUMO

Histone H3.3 lysine-to-methionine substitutions K27M and K36M impair the deposition of opposing chromatin marks, H3K27me3/me2 and H3K36me3/me2. We show that these mutations induce hypotrophic and disorganized eyes in Drosophila eye primordia. Restriction of H3K27me3 spread in H3.3K27M and its redistribution in H3.3K36M result in transcriptional deregulation of PRC2-targeted eye development and of piRNA biogenesis genes, including krimp. Notably, both mutants promote redistribution of H3K36me2 away from repetitive regions into active genes, which associate with retrotransposon de-repression in eye discs. Aberrant expression of krimp represses LINE retrotransposons but does not contribute to the eye phenotype. Depletion of H3K36me2 methyltransferase ash1 in H3.3K27M, and of PRC2 component E(z) in H3.3K36M, restores the expression of eye developmental genes and normal eye growth, showing that redistribution of antagonistic marks contributes to K-to-M pathogenesis. Our results implicate a novel function for H3K36me2 and showcase convergent downstream effects of oncohistones that target opposing epigenetic marks.


Assuntos
Cromatina/química , Elementos de DNA Transponíveis , Histonas/química , Histonas/genética , Discos Imaginais/metabolismo , Mutação , Animais , Animais Geneticamente Modificados , Centrômero/ultraestrutura , Imunoprecipitação da Cromatina , Biologia Computacional/métodos , Metilação de DNA , Drosophila melanogaster , Epigênese Genética , Humanos , Lisina/química , Metionina/química , Camundongos , Microscopia Eletrônica de Varredura , Microscopia de Fluorescência , Fenótipo , RNA-Seq
2.
Proc Natl Acad Sci U S A ; 121(23): e2312173121, 2024 Jun 04.
Artigo em Inglês | MEDLINE | ID: mdl-38805287

RESUMO

The year 2021 marked a decade of holopelagic sargassum (morphotypes Sargassum natans I and VIII, and Sargassum fluitans III) stranding on the Caribbean and West African coasts. Beaching of millions of tons of sargassum negatively impacts coastal ecosystems, economies, and human health. Additionally, the La Soufrière volcano erupted in St. Vincent in April 2021, at the start of the sargassum season. We investigated potential monthly variations in morphotype abundance and biomass composition of sargassum harvested in Jamaica and assessed the influence of processing methods (shade-drying vs. frozen samples) and of volcanic ash exposure on biochemical and elemental components. S. fluitans III was the most abundant morphotype across the year. Limited monthly variations were observed for key brown algal components (phlorotannins, fucoxanthin, and alginate). Shade-drying did not significantly alter the contents of proteins but affected levels of phlorotannins, fucoxanthin, mannitol, and alginate. Simulation of sargassum and volcanic ash drift combined with age statistics suggested that sargassum potentially shared the surface layer with ash for ~50 d, approximately 100 d before stranding in Jamaica. Integrated elemental analysis of volcanic ash, ambient seawater, and sargassum biomass showed that algae harvested from August had accumulated P, Al, Fe, Mn, Zn, and Ni, probably from the ash, and contained less As. This ash fingerprint confirmed the geographical origin and drift timescale of sargassum. Since environmental conditions and processing methods influence biomass composition, efforts should continue to improve understanding, forecasting, monitoring, and valorizing sargassum, particularly as strandings of sargassum show no sign of abating.


Assuntos
Biomassa , Sargassum , Sargassum/química , Ecossistema , Jamaica , Estações do Ano , Erupções Vulcânicas
3.
Cell Mol Life Sci ; 81(1): 62, 2024 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-38280036

RESUMO

Endothelial injury and dysfunction in the artery wall fuel the process of atherosclerosis. As a key epigenetic regulator, Ash2l (Absent, small, or homeotic-Like 2) is involved in regulating vascular injury and its complications. However, the role of Ash2l in atherosclerosis has not yet been fully elucidated. Here, we found increased Ash2l expression in high-cholesterol diet-fed ApoE-/- mice and oxidized LDL (oxLDL) treated endothelial cells (ECs). Furthermore, Ash2l promoted the scavenger receptors transcription by catalyzing histone H3 lysine 4 (H3K4) trimethylation at the promoter region of transcription factor peroxisome proliferator-activated receptor-γ (PPARγ) and triggered the activation of the pro-inflammatory nuclear factor-kappa B (NF-κB) by enhancing interaction between CD36 and toll-like receptor 4 (TLR4). Meanwhile, enhanced expression of scavenger receptors drove more oxLDL uptake by ECs. In vivo studies revealed that ECs-specific Ash2l knockdown reduced atherosclerotic lesion formation and promoted fibrous cap stability in the aorta of ApoE-/- mice, which was partly associated with a reduced endothelial activation by suppressing scavenger receptors and the uptake of lipids by ECs. Collectively, our findings identify Ash2l as a novel regulator that mediates endothelial injury and atherosclerosis. Targeting Ash2l may provide valuable insights for developing novel therapeutic candidates for atherosclerosis.


Assuntos
Aterosclerose , Células Endoteliais , Camundongos , Animais , Células Endoteliais/metabolismo , Lipoproteínas LDL/farmacologia , Lipoproteínas LDL/metabolismo , Aterosclerose/metabolismo , NF-kappa B/metabolismo , Receptores Depuradores/metabolismo , Apolipoproteínas E/genética , Apolipoproteínas E/metabolismo
4.
Proc Natl Acad Sci U S A ; 119(1)2022 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-34969845

RESUMO

The Late Bronze Age Thera eruption was one of the largest natural disasters witnessed in human history. Its impact, consequences, and timing have dominated the discourse of ancient Mediterranean studies for nearly a century. Despite the eruption's high intensity (Volcanic Explosivity Index 7; Dense Rock Equivalent of 78 to 86 km) [T. H. Druitt, F. W. McCoy, G. E. Vougioukalakis, Elements 15, 185-190 (2019)] and tsunami-generating capabilities [K. Minoura et al., Geology 28, 59-62 (2000)], few tsunami deposits are reported. In contrast, descriptions of pumice, ash, and tephra deposits are widely published. This mismatch may be an artifact of interpretive capabilities, given how rapidly tsunami sedimentology has advanced in recent years. A well-preserved volcanic ash layer and chaotic destruction horizon were identified in stratified deposits at Çesme-Baglararasi, a western Anatolian/Aegean coastal archaeological site. To interpret these deposits, archaeological and sedimentological analysis (X-ray fluorescence spectroscopy instrumental neutron activation analysis, granulometry, micropaleontology, and radiocarbon dating) were performed. According to the results, the archaeological site was hit by a series of strong tsunamis that caused damage and erosion, leaving behind a thick layer of debris, distinguishable by its physical, biological, and chemical signature. An articulated human and dog skeleton discovered within the tsunami debris are in situ victims related to the Late Bronze Age Thera eruption event. Calibrated radiocarbon ages from well-constrained, short-lived organics from within the tsunami deposit constrain the event to no earlier than 1612 BCE. The deposit provides a time capsule that demonstrates the nature, enormity, and expansive geographic extent of this catastrophic event.

5.
Annu Rev Entomol ; 69: 239-258, 2024 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-37708417

RESUMO

Since the discovery of the ash tree (Fraxinus spp.) killer emerald ash borer (EAB; Agrilus planipennis) in the United States in 2002 and Moscow, Russia in 2003, substantial detection and management efforts have been applied to contain and monitor its spread and mitigate impacts. Despite these efforts, the pest continues to spread within North America. It has spread to European Russia and Ukraine and is causing sporadic outbreaks in its native range in China. The dynamics of EAB's range expansion events appear to be linked to the lack of resistant ash trees in invaded ranges, facilitated by the abundance of native or planted North American susceptible ash species. We review recently gained knowledge of the range expansion of EAB; its ecological, economic, and social impacts; and past management efforts with their successes and limitations. We also highlight advances in biological control, mechanisms of ash resistance, and new detection and management approaches under development, with the aim of guiding more effective management.


Assuntos
Besouros , Fraxinus , Animais , Larva , América do Norte
6.
BMC Plant Biol ; 24(1): 186, 2024 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-38481155

RESUMO

BACKGROUND: Knowledge of genetic structure and the factors that shape it has an impact on forest management practices. European ash (Fraxinus excelsior L.) has declined dramatically throughout its range as a result of a disease caused by the fungus Hymenoscyphus fraxineus. Despite the need for conservation and restoration of the species, genetic data required to guide these efforts at the country level are scarce. Thereofore, we studied the chloroplast and nuclear genetic diversity of 26 natural common ash populations (1269 trees) in Poland. RESULTS: Chloroplast polymorphisms grouped the populations into two geographically structured phylogenetic lineages ascribed to different glacial refugia (the Balkans and the Eastern Alps). However, the populations demonstrated high genetic diversity (mean AR = 12.35; mean Ho = 0.769; mean He = 0.542) but low differentiation based on nuclear microsatellites (FST = 0.045). Significant spatial genetic structure, consistent with models of isolation by distance, was detected in 14 out of 23 populations. Estimated effective population size was moderate-to-high, with a harmonic mean of 57.5 individuals per population. CONCLUSIONS: Genetic diversity was not homogeneously distributed among populations within phylogenetic gene pools, indicating that ash populations are not equal as potential sources of reproductive material. Genetic differences among populations could be related to their histories, including founder effects or gene flow between evolutionary lineages (admixture). Our results suggest that ash stands across Poland could be treated as two main management units (seed zones). Therefore, despite the homogenizing effect of pollen gene flow known for this species, the genetic structure should be taken into account in the management of the genetic resources of the common ash. Although ash dieback poses an additional challenge for the management of genetic resources, efforts should be directed towards protecting populations with high genetic diversity within defined phylogenetic units, as they may be an important source of adaptive variation for future stands.


Assuntos
Ascomicetos , Fraxinus , Humanos , Fraxinus/genética , Fraxinus/microbiologia , Polônia , Filogenia , Florestas , Variação Genética
7.
BMC Plant Biol ; 24(1): 565, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38879490

RESUMO

BACKGROUND: AP2/ERF is a large family of plant transcription factor proteins that play essential roles in signal transduction, plant growth and development, and responses to various stresses. The AP2/ERF family has been identified and verified by functional analysis in various plants, but so far there has been no comprehensive study of these factors in Chinese prickly ash. Phylogenetic, motif, and functional analyses combined with transcriptome analysis of Chinese prickly ash fruits at different developmental stages (30, 60, and 90 days after anthesis) were conducted in this study. RESULTS: The analysis identified 146 ZbAP2/ERF genes that could be classified into 15 subgroups. The motif analysis revealed the presence of different motifs or elements in each group that may explain the functional differences between the groups. ZbERF13.2, ZbRAP2-12, and ZbERF2.1 showed high levels of expression in the early stages of fruit development. ZbRAP2-4, and ZbERF3.1 were significantly expressed at the fruit coloring stage (R2 and G2). ZbERF16 were significantly expressed at fruit ripening and expression level increased as the fruit continued to develop. Relative gene expression levels of 6 representative ZbAP2/ERFs assessed by RT-qPCR agreed with transcriptome analysis results. CONCLUSIONS: These genes identified by screening can be used as candidate genes that affect fruit development. The results of the analysis can help guide future genetic improvement of Chinese prickly ash and enrich our understanding of AP2/ERF transcription factors and their regulatory functions in plants.


Assuntos
Frutas , Regulação da Expressão Gênica de Plantas , Filogenia , Proteínas de Plantas , Fatores de Transcrição , Frutas/genética , Frutas/crescimento & desenvolvimento , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Perfilação da Expressão Gênica , Genoma de Planta , Genes de Plantas , População do Leste Asiático
8.
Small ; 20(26): e2311203, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38233210

RESUMO

Designing a cost-effective and multifunctional separator that ensures dendrite-free and stable Zn metal anode remains a significant challenge. Herein, a multifunctional cellulose-based separator is presented consisting of industrial waste-fly ash particles and cellulose nanofiber using a facile solution-coating method. The resulting fly ash-cellulose (FACNF) separators enable a high ion conductivity (5.76 mS cm-1) and low desolvation energy barrier of hydrated Zn2+. These features facilitate fast ion transfer kinetics and inhibit water-induced side reactions. Furthermore, experimental results and theoretical simulations confirm that the presence of fly ash particles in FACNF separators effectively accommodate the preferential deposition of Zn(002) planes, due to the weak chemical affinity between Zn(002) plane and fly ash, to mitigate dendrite formation and growth. Consequently, the utilization of FACNF separators causes an impressive cycling performance in both Zn||Zn symmetric cells (1600 h at 2 mA cm-2/1 mAh cm-2) and Zn||(NH4)2V10O25 (NVO) full cells (4000 cycles with the capacity retention of 92.1% at 5 A g-1). Furthermore, the assembled pouch cells can steadily support digital thermometer over two months without generating gas and volume expansion. This work provides new insights for achieving crystallographic uniformity in Zn anodes and realizing cost-effective and long-lasting aqueous zinc-ion batteries (AZIBs).

9.
Mass Spectrom Rev ; 42(4): 1174-1220, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-34859471

RESUMO

Aging of wines and spirits in wooden barrels is an industrial process used to stabilize the color, to improve the limpidity and to enrich the sensorial characteristics of the products. In red wines, the oxygen that permeates through the wood staves promotes the oxidization of polyphenols and the formation of new pigments with consequent stabilization of the wine color. Barrel aging of spirits, such as brandy, whisky, rum, and grappa is finalized to enrich their aroma and improve their sensorial characteristics by the contribute of the compounds released by the wood. Oak is the wood type mostly used in making barrels; however, an increasing interest in the use of chestnut, cherry, acacia, and in less extent, ash and mulberry, has been observed in the recent years. Gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry are the main techniques used to characterize respectively the volatile and polar metabolites released by the wood barrels in the products. In this article are reported the recent advancements in this field.


Assuntos
Vinho , Vinho/análise , Madeira/química , Espectrometria de Massas , Cromatografia Gasosa-Espectrometria de Massas/métodos , Polifenóis/análise
10.
Plant Cell Environ ; 2024 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-38922989

RESUMO

Emerald ash borer (EAB, Agrilus planipennis) is an invasive killer of ash trees (Fraxinus spp.) in North America and Europe. Ash species co-evolved with EAB in their native range in Asia are mostly resistant, although the precise mechanism(s) remain unclear. Very little is also known about EAB or ash tree microbiomes. We performed the first joint comparison of phloem mycobiome and metabolites between a native and a nonnative ash species, infested and uninfested with EAB, in conjunction with investigation of larval mycobiome. Phloem mycobiome communities differed between the tree species, but both were unaffected by EAB infestation. Several indicator taxa in the larval gut shared a similarly high relative abundance only with the native host trees. Widely targeted metabolomics revealed 24 distinct metabolites in native trees and 53 metabolites in nonnative trees, respectively, that differed in relative content between infested and uninfested trees only in one species. Interestingly, four metabolites shared a strong relationship with the phloem mycobiomes, majority of which affected only the native trees. Collectively, our results demonstrate a complex interplay between host tree chemistry and mycobiome, and suggest the shared relationships between the mycobiomes of the native host tree and EAB may reflect their shared co-evolution.

11.
Glob Chang Biol ; 30(6): e17367, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38840430

RESUMO

Wildfire activity is increasing globally. The resulting smoke plumes can travel hundreds to thousands of kilometers, reflecting or scattering sunlight and depositing particles within ecosystems. Several key physical, chemical, and biological processes in lakes are controlled by factors affected by smoke. The spatial and temporal scales of lake exposure to smoke are extensive and under-recognized. We introduce the concept of the lake smoke-day, or the number of days any given lake is exposed to smoke in any given fire season, and quantify the total lake smoke-day exposure in North America from 2019 to 2021. Because smoke can be transported at continental to intercontinental scales, even regions that may not typically experience direct burning of landscapes by wildfire are at risk of smoke exposure. We found that 99.3% of North America was covered by smoke, affecting a total of 1,333,687 lakes ≥10 ha. An incredible 98.9% of lakes experienced at least 10 smoke-days a year, with 89.6% of lakes receiving over 30 lake smoke-days, and lakes in some regions experiencing up to 4 months of cumulative smoke-days. Herein we review the mechanisms through which smoke and ash can affect lakes by altering the amount and spectral composition of incoming solar radiation and depositing carbon, nutrients, or toxic compounds that could alter chemical conditions and impact biota. We develop a conceptual framework that synthesizes known and theoretical impacts of smoke on lakes to guide future research. Finally, we identify emerging research priorities that can help us better understand how lakes will be affected by smoke as wildfire activity increases due to climate change and other anthropogenic activities.


Assuntos
Ecossistema , Lagos , Fumaça , Incêndios Florestais , Fumaça/análise , América do Norte , Monitoramento Ambiental
12.
Glob Chang Biol ; 30(1): e16995, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37916642

RESUMO

Wildfires are increasing in frequency, intensity, and extent globally due to climate change and they can alter forest composition, structure, and function. The destruction and subsequent regrowth of young vegetation can modify the ecosystem evapotranspiration and downstream water availability. However, the response of forest recovery on hydrology is not well known with even the sign of evapotranspiration and water yield changes following forest fires being uncertain across the globe. Here, we quantify the effects of forest regrowth after catastrophic wildfires on evapotranspiration and runoff in the world's tallest angiosperm forest (Eucalyptus regnans) in Australia. We combine eddy covariance measurements including pre- and post-fire periods, mechanistic ecohydrological modeling and then extend the analysis spatially to multiple fires in eucalypt-dominated forests in south-eastern Australia by utilizing remote sensing. We find a fast recovery of evapotranspiration which reaches and exceeds pre-fire values within 2 years after the bushfire, a result confirmed by eddy covariance data, remote sensing, and modeling. Such a fast evapotranspiration recovery is likely generalizable to tall eucalypt forests in south-eastern Australia as shown by remote sensing. Once climate variability is discounted, ecohydrological modeling shows evapotranspiration rates from the recovering forest which reach peak values of +20% evapotranspiration 3 years post-fire. As a result, modeled runoff decreases substantially. Contrary to previous research, we find that the increase in modeled evapotranspiration is largely caused by the aerodynamic effects of a much shorter forest height leading to higher surface temperature, higher humidity gradients and therefore increased transpiration. However, increases in evapotranspiration as well as decreases in runoff caused by the young forest are constrained by energy and water limitations. Our result of an increase in evapotranspiration due to aerodynamic warming in a shorter forest after wildfires could occur in many parts of the world experiencing forest disturbances.


Assuntos
Incêndios , Incêndios Florestais , Ecossistema , Água , Florestas
13.
FASEB J ; 37(3): e22803, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36753389

RESUMO

Methyltransferase like 3 (METTL3), a primary N6-methyladenosine (m6A) methyltransferase, has been implicated in various biological and pathological processes including immune responses. However, the functions and mechanisms of METTL3 in pathogenic T helper (Th)17 cells are poorly understood. Here we found significantly decreased METTL3 expression along with reduced m6A levels in eyeballs and T cells of experimental autoimmune uveitis (EAU). Overexpression of METTL3 ameliorated the development of EAU and suppressed pathogenic Th17 cell responses in vivo and in vitro. Mechanistically, METTL3 promoted the expression of absent, small, or homeotic-like 1 (ASH1L) via enhancing its stability in a YT521-B homology domain containing 2 (YTHDC2)-dependent manner, which further decreased the expression of IL-17 and IL-23 receptor (IL-23R), resulting in reduced pathogenic Th17 responses. Together, our data reveal a pivotal role of METTL3 in regulating pathogenic Th17 responses, which may contribute to human uveitis therapy.


Assuntos
Proteínas de Ligação a DNA , Histona-Lisina N-Metiltransferase , Metiltransferases , Células Th17 , Uveíte , Proteínas de Ligação a DNA/metabolismo , Histona-Lisina N-Metiltransferase/metabolismo , Metiltransferases/genética , Metiltransferases/metabolismo , RNA Mensageiro/genética , Uveíte/genética , Uveíte/metabolismo , Animais , Doenças Autoimunes , Modelos Animais de Doenças
14.
J Microsc ; 294(2): 239-250, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38597232

RESUMO

Engineered cementitious composites (ECC) are a class of high-performing fibre-reinforced cementitious materials recognised for their increased ductility and durability compared to conventional cement-based materials, owing to their autogenously controlled tight crack widths, even when subjected to high strains. To reduce ECC's environmental impact, this research examines the use of a low-clinker binder - limestone-calcined clay cement (LC3) - as an alternative to portland cement (PC), along with fly ash to further reduce the clinker proportion and the embodied CO2 of the formulations. In conventional concrete, LC3 hydrates to a denser microstructure resulting from the synergistic reaction between limestone and calcined clay. At the lower water contents typical of ECC and with the presence of fly ash, the influence of the binder composition on the microstructure is difficult to anticipate. To examine the influence of these compositional variables on microstructure, permeability and durability, the sulphate resistance of LC3-based ECC is explored. Specifically, the ECC-LC3 blends are designed with high clinker replacement rate of 75% by mass of binder and contain either conventional fly ash or reclaimed fly ash at 50% by mass of binder. Expansion of ECC-LC3 samples subjected to standard sodium sulphate test conditions was measured up to 12 months and the depth of penetration of sulphates into the ECC-LC3 of varying compositions was quantified using micro-X-Ray Fluorescence (microXRF) imaging and modelling. The expansion results show that the ECC-LC3 formulations performed better than the PC samples and can provide adequate resistance to external sulphate attack, even when reclaimed fly ashes are used in place of the conventional ash. In addition, the shallow penetration of sulphate into these cementitious composites demonstrates the low diffusion coefficients values that were determined using the quantitative data from MicroXRF imaging.

15.
J Microsc ; 294(2): 117-127, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-37986607

RESUMO

When the first concrete was poured in 1949 for the Hungry Horse Dam (Montana, USA), pozzolan cements had already been used in several major North American dams, including Grand Coulee on the Columbia River (diatomaceous earth explored but ultimately not used), Friant on the San Joaquin River and Altus on the North Fork Red River (pumicite) and Bonneville on the Columbia River and Davis on the Colorado River (calcined clay). But Hungry Horse Dam stands out as the first dam constructed using coal combustion fly ash. Utilising 2.4 million cubic metres of concrete, the dam is located on the South Fork Flathead River, one of the tributaries feeding one of the nation's major waterways, the Columbia River, and closely related to the adjacent Glacier National Park. In this respect, Hungry Horse is directly connected to two momentous periods in modern history - the massive adoption in the 1950s of coal as fuel for power plants, and the ongoing threats to fresh water supply and the rapid retreat of alpine glaciers due to global warming. Two concrete cores from this dam, one with fly ash and one without fly ash, are examined microscopically to explore the long-term suppression of alkali-aggregate reaction by fly ash. The core without fly ash exhibits clear evidence of alkali-aggregate reaction, manifested by sandstone coarse aggregate particles with darkened reaction rims. Sandstone coarse aggregate particles of the same lithology in the core with fly ash are without signs of alkali-aggregate reaction. A detailed examination of the darkened rims indicates that alkali-silica reaction products fill the narrow gaps between adjacent sand grains in the sandstone. This alkali-silica gel infilling allows for optical continuity between adjacent sand grains and is responsible for the classic darkened rim associated with the alkali-aggregate reaction.

16.
Environ Sci Technol ; 58(19): 8457-8463, 2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38685907

RESUMO

Per- and polyfluoroalkyl substances (PFASs) constitute a diverse group of man-made chemicals characterized by their water- and oil-repellent properties and persistency. Given their widespread use in consumer products, PFASs will inevitably be present in waste streams sent to Waste-to-Energy (WtE) plants. We have previously observed a subset of PFASs in residual streams (ashes, treated process water, and flue gas) from a WtE plant. However, the transport and distribution of PFASs inside the WtE plant have remained unaddressed. This study is part of a comprehensive investigation to create a synoptic overview of the distribution of PFASs in WtE residues. PFASs were found in all sample types except for boiler ash. The total levels of 18 individual PFASs (Σ18PFASs) in untreated flue gas ranged from 5.2 to 9.5 ng m-3, decreasing with 35% ± 10% after wet flue gas treatment. Σ18PFASs in the condensate ranged from 46 to 50 ng L-1, of which perfluorohexanoic acid (PFHxA) made up 90% on a ng L-1 basis. PFHxA was also dominant in filter ash, where Σ18PFASs ranged from 0.28 to 0.79 ng g-1. This study shows that flue gas treatment can capture some PFASs and transfer them into WtE residues.


Assuntos
Fluorocarbonos , Fluorocarbonos/análise , Poluentes Químicos da Água/análise , Monitoramento Ambiental
17.
Environ Sci Technol ; 58(1): 859-870, 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38060830

RESUMO

The efficient removal of the highly toxic arsine gas (AsH3) from industrial tail gases under mild conditions remains a formidable challenge. In this study, we utilized the confinement effect of defective carbon nanotubes to fabricate a CuO cluster catalyst (CuO/ACNT), which exhibited a capacity much higher than that of CuO supported on pristine multiwalled carbon nanotubes (MWCNT) (CuO/PCNT) for catalytically oxidizing AsH3 under ambient conditions. The experimental and theoretical results show that nitric acid steam treatment could induce MWCNT surface structural defects, which facilitated more stable anchoring of CuO and then improved the oxygen activation ability, therefore leading to excellent catalytic performance. Density functional theory (DFT) calculations revealed that the catalytic oxidation of AsH3 proceeded through stepwise dehydrogenation and subsequent recombination with oxygen to form As2O3 as the final product.


Assuntos
Nanotubos de Carbono , Nanotubos de Carbono/química , Temperatura , Gases , Oxigênio , Oxirredução
18.
Environ Sci Technol ; 58(15): 6704-6715, 2024 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-38574268

RESUMO

The transformation of toxic arsine (AsH3) gas into valuable elemental arsenic (As0) from industrial exhaust gases is important for achieving sustainable development goals. Although advanced arsenic removal catalysts can improve the removal efficiency of AsH3, toxic arsenic oxides generated during this process have not received adequate attention. In light of this, a novel approach for obtaining stable As0 products was proposed by performing controlled moderate oxidation. We designed a tailored Ni-based catalyst through an acid etching approach to alter interactions between Ni and NaY. As a result, the 1Ni/NaY-H catalyst yielded an unprecedented proportion of As0 as the major product (65%), which is superior to those of other reported catalysts that only produced arsenic oxides. Density functional theory calculations clarified that Ni species changed the electronic structure of oxygen atoms, and the formed [NiIII-OH (µ-O)] active centers facilitated the adsorption of AsH2*, AsH*, and As* reaction intermediates for As-H bond cleavage, thereby decreasing the direct reactivity of oxygen with the arsenic intermediates. This work presents pioneering insights into inhibiting excessive oxidation during AsH3 removal, demonstrating potential environmental applications for recovery of As0 from toxic AsH3.


Assuntos
Arsênio , Zeolitas , Níquel/química , Elétrons , Oxigênio , Gases
19.
Environ Sci Technol ; 58(5): 2574-2583, 2024 Feb 06.
Artigo em Inglês | MEDLINE | ID: mdl-38266484

RESUMO

To recover multimedia mercury from coal-fired power plants, a novel N-containing conjugated polymer (polyaniline and polypyrrole) functionalized fly ash was prepared, which could continuously adsorb 99.2% of gaseous Hg0 at a high space velocity of 368,500 h-1 and nearly 100% of aqueous Hg2+ in the solution pH range of 2-12. The adsorption capacities of Hg0 and Hg2+ reach 1.62 and 101.36 mg/g, respectively. Such a kind of adsorbent has good environmental applicability, i.e. good resistance to coexisting O2/NO/SO2 and coexisting Na+/K+/Ca2+/Mg2+/SO42-. This adsorbent has very low specific resistances (6 × 106-5 × 109 Ω·cm) and thus can be easily collected by an electrostatic precipitator under low-voltage (0.1-0.8 kV). The Hg-saturated adsorbent can desorb almost 100% Hg under relatively low temperature (<250 °C). Characterization and theoretical calculations reveal that conjugated-N is the critical site for adsorbing both Hg0 and Hg2+ as well as activating chlorine. Gaseous Hg0 is oxidized and adsorbed in the form of HgXClX(ad), while aqueous Hg2+ is adsorbed to form a complex with conjugated-N, and parts of Hg2+ are reduced to Hg+ by conjugated-N. This adsorbent can be easily large-scale manufactured; thus, this novel solid waste functionalization method is promising to be applied in coal-fired power plants and other Hg-involving industrial scenes.


Assuntos
Poluentes Atmosféricos , Mercúrio , Cinza de Carvão/química , Poluentes Atmosféricos/análise , Mercúrio/análise , Multimídia , Polímeros , Carvão Mineral , Pirróis , Gases , Centrais Elétricas
20.
Acta Pharmacol Sin ; 45(3): 558-569, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37903897

RESUMO

Endothelial dysfunction is a common complication of diabetes mellitus (DM) and contributes to the high incidence and mortality of cardiovascular and cerebrovascular diseases. Aberrant epigenetic regulation under diabetic conditions, including histone modifications, DNA methylation, and non-coding RNAs (ncRNAs) play key roles in the initiation and progression of diabetic vascular complications. ASH2L, a H3K4me3 regulator, triggers genetic transcription, which is critical for physiological and pathogenic processes. In this study we investigated the role of ASH2L in mediating diabetic endothelial dysfunction. We showed that ASH2L expression was significantly elevated in vascular tissues from diabetic db/db mice and in rat aortic endothelial cells (RAECs) treated with high glucose medium (11 and 22 mM). Knockdown of ASH2L in RAECs markedly inhibited the deteriorating effects of high glucose, characterized by reduced oxidative stress and inflammatory responses. Deletion of endothelial ASH2L in db/db mice by injection of an adeno-associated virus (AAV)-endothelial specific system carrying shRNA against Ash2l (AAV-shAsh2l) restored the impaired endothelium-dependent relaxations, and ameliorated DM-induced vascular dysfunction. We revealed that ASH2L expression activated reductase STEAP4 transcription in vitro and in vivo, which consequently elevated Cu(I) transportation into ECs by the copper transporter CTR1. Excess copper produced by STEAP4-mediated copper uptake triggered oxidative stress and inflammatory responses, resulting in endothelial dysfunction. Our results demonstrate that hyperglycemia triggered ASH2L-STEAP4 axis contributes to diabetic endothelial dysfunction by modulating copper uptake into ECs and highlight the therapeutic potential of blocking the endothelial ASH2L in the pathogenesis of diabetic vascular complications.


Assuntos
Diabetes Mellitus , Angiopatias Diabéticas , Ratos , Camundongos , Animais , Cobre/metabolismo , Cobre/farmacologia , Regulação para Cima , Células Endoteliais/metabolismo , Epigênese Genética , Células Cultivadas , Angiopatias Diabéticas/etiologia , Glucose/metabolismo , Endotélio Vascular
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA