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1.
Curr Oncol ; 31(7): 3643-3656, 2024 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-39057140

RESUMO

To help determine the unmet need for improved diagnostic tools to evaluate patients with nonspecific signs and/or symptoms (NSSS) and suspicion of cancer, we examined patient characteristics, diagnostic journey, and cancer incidence of patients with NSSS within The US Oncology Network (The Network), a secondary care community oncology setting. This retrospective, observational cohort study included patients aged ≥40 years with ≥1 NSSS in their problem list at their first visit within The Network (the index date) between 1 January 2016 and 31 December 2020. Patients were followed longitudinally with electronic health record data for initial cancer diagnosis, new noncancer diagnosis, death, end of study observation period, or 12 months, whichever occurred first. Of 103,984 patients eligible for inclusion, 96,722 presented with only 1 NSSS at index date; 6537/103,984 (6.3%) were diagnosed with 1 primary cancer within 12 months after the index date; 3825/6537 (58.5%) with hematologic malignancy, and 2712/6537 (41.5%) with solid tumor. Among patients diagnosed with cancer (n = 6774), the median time to cancer diagnosis after their first visit within The Network was 5.13 weeks. This study provides a real-world perspective on cancer incidence in patients with NSSS referred to a secondary care setting and highlights the unmet need for improved diagnostic tools to improve cancer outcomes.


Assuntos
Neoplasias , Atenção Secundária à Saúde , Humanos , Estudos Retrospectivos , Neoplasias/epidemiologia , Feminino , Masculino , Pessoa de Meia-Idade , Idoso , Estados Unidos/epidemiologia , Adulto , Idoso de 80 Anos ou mais
2.
Chemosphere ; 363: 142822, 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38986778

RESUMO

The toxicity of triclosan (TCS) to various aquatic organisms has been demonstrated at environmental concentrations. However, the effects and mechanisms of TCS on toxic cyanobacteria remains largely unexplored. This study investigated the physiological and molecular variations in two representative toxic Microcystis species (M. aeruginosa and M. viridis) under exposure to TCS for 12 d. Our findings demonstrated that the median effective concentration (EC50) of TCS for both Microcystis species were close to the levels detected in the environment (M. aeruginosa: 9.62 µg L-1; M. viridis: 27.56 µg L-1). An increased level of reactive oxygen species (ROS) was observed in Microcystis, resulting in oxidative damage when exposed to TCS at concentrations ranging from 10 µg L-1 to 50 µg L-1. The photosynthetic activity of Microcystis had a certain degree of recovery capability at low concentrations of TCS. Compared to M. aeruginosa, the higher recovery capability of the photosynthetic system in M. viridis would be mainly attributed to the increased ability for PSII repair and phycobilisome synthesis. Additionally, the synthesis of microcystins in the two species and the release rate in M. viridis significantly increased under 10-50 µg L-1 TCS. At the molecular level, exposure to TCS at EC50 for 12 d induced the dysregulation of genes associated with photosynthesis and antioxidant system. The upregulation of genes associated with microcystin synthesis and nitrogen metabolism further increased the potential risk of microcystin release. Our results revealed the aquatic toxicity and secondary ecological risks of TCS at environmental concentrations, and provided theoretical data with practical reference value for TCS monitoring.

3.
Water Res ; 262: 122120, 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39083900

RESUMO

Saltmarshes along the Chinese coast are threatened by the invasion of Spartina alterniflora (S. alterniflora). This study was carried out in the Andong Shoal, Hangzhou Bay, China, with the aim of comprehending the intricate impacts of S. alterniflora invasion on greenhouse gases (GHG) production and emissions. To address this issue, we thoroughly examined the chemistry of dissolved organic matter (DOM) and the rate of surface water-porewater interaction. Porewater and surface water samples were collected from farm land, S. alterniflora invaded areas, and Scirpus mariqueter (S. mariqueter) dominated areas. The findings indicated that the invasion of S. alterniflora impeded the interaction between surface water and porewater, resulting in reduced porewater exchange rates within its affected region (0.015-0.440 cm d-1), in contrast to areas dominated by S. mariqueter (9.635-18.232 cm d-1). The invasion also increased dissolved organic carbon concentration in porewater and created a stable and closed soil environment that resulted in DOM with smaller molecule sizes and higher humification levels. The presence of high tryptophan-like fluorescent DOM caused an increase in the production of methane and carbon dioxide in S. alterniflora invaded area. However, both limited surface-porewater exchange and significant differences in GHG concentrations between porewater and surface water suggested that the aerenchyma tissues of S. alterniflora may play an important role in transporting GHG from soil to the atmosphere.

4.
Ecotoxicol Environ Saf ; 281: 116576, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38878562

RESUMO

The accumulation of rare earth elements (REEs) in the global environment poses a threat to plant health and ecosystem stability. Stomata located on leaves serve as the primary site for plant responses to REE-related threats. This study focused on lanthanum [La(III)], a prevalent REE in the atmospheric environment. Using interdisciplinary techniques, it was found that La(III) (≤80 µM) interfered with the fundamental rhythms of stomatal opening, related gene expression, and evapotranspiration in plants. Specifically, when exposed to low concentrations of La(III) (15 and 30 µM), the expression levels of six genes were increased, stomatal opening was enhanced, and the evapotranspiration rate was accelerated. The interference on stomatal rhythms was enhanced with higher concentrations of La(III) (60 and 80 µM), increasing the expression levels of six genes, stomatal opening, and evapotranspiration rate. To counter the interference of low concentrations of La(III) (15 and 30 µM), plants accelerated nutrient replenishment through La(III)-induced endocytosis, which the redundant nutrients enhanced photosynthesis. However, replenished nutrients failed to counter the disruption of plant biological rhythms at higher concentrations of La(III) (60 and 80 µM), thus inhibiting photosynthesis due to nutrient deficit. The interference of La(III) on these biological rhythms negatively affected plant health and ecosystem stability.


Assuntos
Arabidopsis , Regulação da Expressão Gênica de Plantas , Lantânio , Estômatos de Plantas , Transpiração Vegetal , Lantânio/toxicidade , Estômatos de Plantas/efeitos dos fármacos , Estômatos de Plantas/fisiologia , Arabidopsis/efeitos dos fármacos , Arabidopsis/genética , Arabidopsis/fisiologia , Regulação da Expressão Gênica de Plantas/efeitos dos fármacos , Transpiração Vegetal/efeitos dos fármacos , Fotossíntese/efeitos dos fármacos , Folhas de Planta/efeitos dos fármacos
5.
Environ Sci Technol ; 58(27): 11988-11997, 2024 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-38875444

RESUMO

Thousands of mass peaks emerge during molecular characterization of natural dissolved organic matter (DOM) using ultrahigh-resolution mass spectrometry. While mass peaks assigned to certain molecular formulas have been extensively studied, the uncharacterized mass peaks that represent a significant fraction of organic matter and convey biogenic elements and energy have been previously ignored. In this study, we introduce the term dark DOM (DDOM) for unassigned mass peaks and have explored its characteristics and environmental behaviors using a data set of 38 DOM extracts covering the Yangtze River-to-ocean continuum. We identified a total of 9141 DDOM molecules, which exhibited higher molecular weight and greater diversity than the DOM subset with assigned DOM formulas. Although DDOM contributed a smaller fraction of relative abundance, it significantly impacted the molecular weight and molecular composition of bulk DOM. A portion of DDOM with higher molecular weight was found to increase molecular abundance across the river-to-ocean continuum. These compounds could contain halogenated organic molecules and might have a high potential to contribute to the refractory organic carbon pool. With this study, we underline the contribution of dark matter to the total DOM pool and emphasize that more DDOM research is needed to understand its contribution to global biogeochemical cycles and carbon sequestration.


Assuntos
Rios , Rios/química , Oceanos e Mares , Monitoramento Ambiental , Espectrometria de Massas , Compostos Orgânicos/análise
6.
Aging (Albany NY) ; 16(12): 10216-10238, 2024 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-38943627

RESUMO

This study aimed to reveal the specific role of early growth response protein 1 (EGR1) and nuclear receptor 4A3 (NR4A3) in nucleus pulposus cells (NPCs) and the related molecular mechanism and to identify a new strategy for treating intervertebral disc degeneration (IVDD). Bioinformatics analysis was used to explore and predict IVDD-related differentially expressed genes, and chromatin immunoprecipitation sequencing (ChIP-seq) revealed NR4A3 as the EGR1 target gene. An in vitro NPC model induced by tributyl hydrogen peroxide (TBHP) and a rat model induced by fibrous ring acupuncture were established. Western blotting, quantitative real-time polymerase chain reaction (qRT-PCR), immunohistochemical staining, immunofluorescence staining, and flow cytometry were used to detect the effects of EGR1 and NR4A3 knockdown and overexpression on NPC apoptosis and the expression of extracellular matrix (ECM) anabolism-related proteins. Interactions between EGR1 and NR4A3 were analyzed via ChIP-qPCR and dual luciferase assays. EGR1 and NR4A3 expression levels were significantly higher in severely degenerated discs (SDD) than in mildly degenerated discs (MDD), indicating that these genes are important risk factors in IVDD progression. ChIP-seq and RNA-seq revealed NR4A3 as a direct downstream target of EGR1, and this finding was verified by ChIP-qPCR and dual luciferase reporter experiments. Remarkably, the rescue experiments showed that EGR1 promotes TBHP-induced NPC apoptosis and impairs ECM anabolism, dependent on elevated NR4A3 expression. In summary, the EGR1-NR4A3 axis mediates the progression of NPC apoptosis and ECM impairment and is a potential therapeutic target in IVDD.


Assuntos
Apoptose , Proteína 1 de Resposta de Crescimento Precoce , Degeneração do Disco Intervertebral , Núcleo Pulposo , Estresse Oxidativo , Receptores dos Hormônios Tireóideos , Adulto , Animais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Ratos , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Proteína 1 de Resposta de Crescimento Precoce/metabolismo , Proteína 1 de Resposta de Crescimento Precoce/genética , Degeneração do Disco Intervertebral/metabolismo , Degeneração do Disco Intervertebral/genética , Degeneração do Disco Intervertebral/patologia , Proteínas do Tecido Nervoso , Núcleo Pulposo/metabolismo , Núcleo Pulposo/patologia , Ratos Sprague-Dawley , Receptores de Esteroides/metabolismo , Receptores de Esteroides/genética , Receptores dos Hormônios Tireóideos/metabolismo , Receptores dos Hormônios Tireóideos/genética , Regulação para Cima
7.
J Hazard Mater ; 473: 134711, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38795491

RESUMO

Coastal wetland soils play a critical role in the global mercury (Hg) cycle, serving as both an important repository for total mercury (THg) and a hotspot for methylmercury (MeHg) production. This study investigated Hg pollution in soils dominated by Phragmites australis (PA) and Spartina alterniflora (SA) across five representative China's coastal wetlands (Yellow River (YR), Linhong River (LHR), Yangtze River (CJR), Min River (MR), and Nanliu River (NLR)). The THg concentrations ranged from 16.7 to 446.0 (96.3 ± 59.3 ng g-1, dw), while MeHg concentrations varied from 0.01 to 0.81 (0.12 ± 0.12 ng g-1, dw). We further evaluated Hg risk in these wetlands using potential ecological risk index (Er) and geographical enrichment factor (Igeo). Most wetlands exhibited low to moderate ecological risk, except the PA habitat in the YR wetland, showing moderate to high risk. Soil organic matter significantly influenced THg and MeHg distribution, while MeHg% correlated well with soil salinity and pH. These findings highlight the importance of organic-rich coastal wetland soils in THg and MeHg accumulation, with the soil properties influencing net MeHg production. Furthermore, SA habitat generally exhibited higher MeHg%, suggesting its invasion elevates the ecological risk of MeHg in coastal wetlands. ENVIRONMENTAL IMPLICATION: Mercury (Hg), a global pollutant, poses great risks to wildlife and humans. Since industrialization, anthropogenic Hg release surpassed natural sources. Long-term exposure leads to biomagnification of Hg. This study assessed Hg and methylmercury pollution and risks in soils of five China's coastal wetlands dominated by Phragmites australis and Spartina alterniflora. Environmental factors (total carbon, total organic carbon, total nitrogen, salinity, pH) were analyzed to reveal key variables influencing Hg pollution and methylation. Essential for quantifying Hg pollution in coastal wetlands, the findings provide a scientific basis for effective wetland conservation policies and addressing environmental health in these regions.


Assuntos
Monitoramento Ambiental , Mercúrio , Compostos de Metilmercúrio , Poluentes do Solo , Áreas Alagadas , Compostos de Metilmercúrio/análise , China , Mercúrio/análise , Poluentes do Solo/análise , Solo/química
8.
Sci Rep ; 14(1): 12219, 2024 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-38806680

RESUMO

Choroid plexus tumors (CPT) are rare and highly vascularized neoplasms that have three histologically confirmed diagnoses, including choroid plexus papilloma, atypical choroid plexus papilloma, and choroid plexus carcinoma (CPC). This study aimed to determine the epidemiology and survival of patients with CPTs and develop a nomogram to quantify the prognosis of the patients with CPT. Data of 808 patients who were diagnosed as CPT between 2000 and 2020 was obtained from the surveillance, epidemiology, and end results database. Descriptive analysis was used to assess the distribution and tumor-related characteristics of the patients with CPT. Independent prognostic factors for patients with CPT were identified by univariate and multivariate Cox regression analysis. The nomogram was established and evaluated by receiver operating characteristic curve, and decision curve analysis (DCA), calibration curves. The independent prognostic factors for patients with CPT are age, tumor size, surgery, chemotherapy, tumor number, pathologies, and race. For the prognostic nomogram, the area under the curve (AUC) of 60-, 120-, and 180-months were 0.855, 0.869 and 0.857 in the training set and 0.836, 0.864 and 0.922 in the test set. The DCA and calibration curve indicated the good performance of the nomogram. Patients with CPTs can be diagnosed at any age. Among the three histopathological tumors, patients with CPC had the worst prognosis. The nomogram was established to predict the prognosis of patients with CPT, which had satisfactory accuracy, and clinical utility may benefit for clinical decision-making.


Assuntos
Neoplasias do Plexo Corióideo , Nomogramas , Programa de SEER , Humanos , Neoplasias do Plexo Corióideo/patologia , Neoplasias do Plexo Corióideo/epidemiologia , Neoplasias do Plexo Corióideo/diagnóstico , Neoplasias do Plexo Corióideo/mortalidade , Feminino , Masculino , Prognóstico , Pessoa de Meia-Idade , Adulto , Adolescente , Idoso , Criança , Curva ROC , Adulto Jovem , Pré-Escolar , Lactente , Carcinoma
9.
Environ Res ; 252(Pt 3): 119040, 2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38692424

RESUMO

Floods in global large rivers modulate the transport of dissolved organic carbon (DOC) and estuarine hydrological characteristics significantly. This study investigated the impact of a severe flood on the sources and age of DOC in the Yangtze River Estuary (YRE) in 2020. Comparing the flood period in 2020 to the non-flood period in 2017, we found that the flood enhanced the transport of young DOC to the East China Sea (ECS), resulting in significantly enriched Δ14C-DOC values. During the flood period, the proportion of modern terrestrial organic carbon (OC) was significantly higher compared to the non-flood period. Conversely, the proportion of pre-aged sediment OC was significantly lower during the flood period. The high turbidity associated with the flood facilitated rapid transformation and mineralization of sedimentary and fresh terrestrial OC, modifying the sources of DOC. The flux of modern terrestrial OC transported to the ECS during the flood period was 1.58 times higher than that of the non-flood period. These findings suggest that floods can modulate the sources and decrease the age of DOC, potentially leading to increased greenhouse gas emissions. Further research is needed to understand the long-term impacts of floods on DOC dynamics in global estuaries.


Assuntos
Carbono , Estuários , Inundações , Rios , China , Rios/química , Carbono/análise , Monitoramento Ambiental , Sedimentos Geológicos/análise , Sedimentos Geológicos/química , Poluentes Químicos da Água/análise
10.
Water Res ; 257: 121719, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38728783

RESUMO

Biological soil crusts (BSCs) are typical covers in arid and semiarid regions. The dissolved organic matter (DOM) of BSCs can be transported to various aquatic ecosystems by rainfall-runoff processes. However, the spatiotemporal variation in quality and quantity of DOM in runoff remains unclear. Herein, four kinds of runoff plots covered by four successional stages of BSCs were set up on slopes, including bare runoff plot (BR), cyanobacteria crust covered runoff plot (CR), mixed crust covered runoff plot (MIR), and moss crust covered runoff plot (MOR). The quantity and quality of DOM in runoff during rainfall was investigated based on the stimulated rainfall experiments combined with optical spectroscopy and ultra-high resolution mass spectrometry analyses. The results showed that the DOM concentrations (i.e., 0.30 to 45.25 mg L-1) in runoff followed the pattern of MOR>MIR>CR>BR, and they were exponentially decreased with rainfall duration. The DOM loss rate of BR (8.26 to 11.64 %) was significantly greater than those of CR, MIR, and MOR (0.84 to 3.22 %). Highly unsaturated compounds (HUCs), unsaturated aliphatic compounds (UACs), saturated compounds (SCs), and peptide-like compounds (PLCs) were the dominated compounds of the water extractable DOM from the original soils. Thereinto, PLCs and UACs were more easily leached into runoff during rainfall. The relatively intensity of HUCs in runoff generally decreased with rainfall duration, while the relatively intensities of UACs, PLCs, and SCs slightly increased with rainfall duration. These findings suggested that the DOM loss rate was effectively decreased with the successional of BSCs during rainfall; meanwhile, some labile compounds (e.g., PLCs and UACs) were transported into various aquatic ecosystems by rainfall-runoff processes.


Assuntos
Chuva , Solo , Solo/química , Compostos Orgânicos , Monitoramento Ambiental/métodos , Movimentos da Água
11.
Environ Res ; 257: 119251, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-38815714

RESUMO

The bioavailable diverse dissolved organic matter (DOM) present in glacial meltwater significantly contributes to downstream carbon cycling in mountainous regions. However, the comprehension of molecular-level characteristics of riverine DOM, from tributary to downstream and their fate in glacier-fed desert rivers remains limited. Herein, we employed spectroscopic and high-resolution mass spectrometry techniques to study both optical and molecular-level characteristics of DOM in the Tarim River catchment, northwest China. The results revealed that the DOC values in the downstream were higher than those in the tributaries, yet they remained comparable to those found in other glacier-fed streams worldwide. Five distinct components were identified using EEM-PARAFAC analysis in both tributary and downstream samples. The dominance of three protein-like components in tributary samples, contrasting with a higher presence of humic-like components in downstream samples, which implied that the dilution and alterations of the glacier DOM signature and overprinting with terrestrial-derived DOM. Molecular composition revealed that thousands of compounds with higher molecular weight and increased aromaticity were transformed, generated and introduced from terrestrial inputs during downstream transportation. The twofold rise in polycyclic aromatic and polyphenolic compounds observed downstream compared to tributaries indicated a greater influx of terrestrial organic matter introduced into the downstream during water transportation. The study suggests that the glacier-sourced DOM experienced minimal photodegradations, with limited influence from human activities, while also being shaped by terrestrial inputs during its transit in the alpine-arid region. This unique scenario offers valuable insights into comprehending the fate of DOM originating from glacial meltwater in arid mountainous regions.


Assuntos
Camada de Gelo , Rios , China , Rios/química , Camada de Gelo/química , Monitoramento Ambiental/métodos , Compostos Orgânicos/análise , Poluentes Químicos da Água/análise , Substâncias Húmicas/análise , Espectrometria de Massas , Clima Desértico
12.
Sci Total Environ ; 928: 172253, 2024 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-38599400

RESUMO

Antimony (Sb) pollution poses a noteworthy risk to human health and ecosystem sustainability, therefore effective, eco-friendly, and widely accepted restoration methods are urgently needed. This study introduces a new approach of using La(III) foliar application on Solanum nigrum L. (S. nigrum), a cadmium hyperaccumulator, to improve its photosynthetic and root systems under Sb stress, resulting in a higher biomass. Notably, La(III) also enhances endocytosis in root cells, facilitating efficient and non-selective remediation of both Sb(III) and Sb(V) forms. The absorption of Sb by root cell endocytosis was observed visually with a confocal laser scanning microscope. The subcellular distribution of Sb in the cell wall of S. nigrum is reduced. And the antioxidant enzyme activity system is improved, resulting in an enhanced Sb tolerance in S. nigrum. Based on the existing bibliometric analysis, this paper identified optimal conditions for S. nigrum to achieve maximum translocation and bioconcentration factor values for Sb. The foliar application of La(III) on plants treated with Sb(III), Sb(V), and a combination of both resulted in translocation factor values of 0.89, 1.2, 1.13 and bioconcentration factor values of 11.3, 12.81, 14.54, respectively. Our work suggests that La(III)-enhanced endocytosis of S. nigrum root cells is a promising remediation strategy for Sb-contaminated environments.


Assuntos
Antimônio , Biodegradação Ambiental , Endocitose , Poluentes do Solo , Solanum nigrum , Solanum nigrum/metabolismo , Poluentes do Solo/metabolismo , Antimônio/metabolismo , Endocitose/fisiologia , Raízes de Plantas/metabolismo , Metais Terras Raras/metabolismo
13.
Micromachines (Basel) ; 15(3)2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38542579

RESUMO

Generalized broadband operation facilitates multifunction or multiband highly integrated applications, such as modern transceiver systems, where ultra-wideband bidirectional passive mixers are favored to avoid a complex up/down-conversion scheme. In this paper, a modified Ruthroff-type transmission line transformer (TLT) balun is presented to enhance the isolation of the mixer from the local oscillator (LO) to the radio frequency (RF). Compared to the conventional methods, the proposed Ruthroff-type architecture adopts a combination of shunt capacitors and parallel coupled lines to improve the return loss at the LO port, thus effectively avoiding the area consumption for the diode-to-balun impedance transformation while simultaneously providing a suitable point for IF extraction. In addition, a parallel compensation technique consisting of an inductor and resistor is applied to the RF balun to significantly improve the amplitude/phase balance performance over a wide bandwidth. Benefiting from the aforementioned operations, an isolation-enhanced 8-30 GHz passive double-balanced mixer is designed as a proof-of-principle demonstration via 0.15-micrometer GaAs p-HEMT technology. It exhibits ultra-broadband performance with 7 dB average conversion loss and 50 dB LO-to-RF isolation under 15 dBm LO power. The monolithic microwave integrated circuit area is 0.96 × 1.68 mm2 including all pads.

14.
ACS Environ Au ; 4(1): 31-41, 2024 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-38250340

RESUMO

Analyzing the molecular composition change of dissolved organic matter (DOM) during transportation in estuaries can enhance our understanding of the fate of DOM. However, the impact of hydrologic conditions resulting from large river plumes on the DOM cycle are less explored, and previous studies were insufficient to capture the molecular fate that occur during the transportation process. In this study, we used a range of bulk and optical techniques, as well as Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), to determine the concentration and characteristics of DOM along two trajectories of downstream plumes of diluted water of the Yangtze (Changjiang) River estuary (YRE) during the high discharge season. These two plumes situated along the route of the summer Changjiang diluted water (CDW) have been identified and named CDW-North (CDW-N) and CDW-South (CDW-S), respectively. Despite having the same riverine end-member origin, the turbidity zone in YRE significantly modifies the molecular characteristics and composition of DOM. The results of FT-ICR MS indicated a spatial variation of DOM composition in the coastal zone of the two plumes. The relative intensities of the CHO, CHOS, and CHONS compounds are negatively correlated with salinity. In addition, the coastal zones of both CDW-N and CDW-S are characterized by more autochthonous DOM sources. More CHON compounds in CDW-N are probably due to the production of autochthonous DOM in offshore waters. The activity of phytoplankton increased the surface dissolved oxygen level of CDW-N in the coastal zone. However, the hypoxic zone formed at the bottom of the CDW-N due to microbial degradation of organic matter and may further benefit the preservation of CHON compounds. Our study emphasizes that the characteristics and composition of the estuarine DOM can be significantly shaped by distinct large river plumes. Furthermore, using FT-ICR MS in combination with complementary techniques can better assist in identifying the sources and transformation mechanisms of estuarine DOM in large river plume-affected systems and provide more valuable insights into the role of DOM in the estuarine biogeochemical cycle.

15.
Sci Total Environ ; 914: 169827, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38190911

RESUMO

Understanding the molecular composition and fate of dissolved organic matter (DOM) during transport in estuaries is essential for gaining a comprehensive understanding of its role within the global biogeochemical cycle. In 2020, a catastrophic flood occurred in the Yangtze River basin. It is currently unknown whether differences in hydrologic conditions due to extreme flooding will significantly impact the estuarine to oceanic DOM cycle. We determined the DOM composition in the Yangtze River estuary (YRE) to the East China Sea by using Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS) during the high discharge and the flood period (monthly average discharge was 1.2 times higher) on the same trajectory. Our study found that the composition of DOM is more diverse, and more DOM molecules were introduced to the YRE during the flood, especially in the freshwater end member. The result revealed that the DOM was significantly labile and unstable during the flood period. A total of 1840 unique molecular formulas were identified during the flood period, most of which were CHON, CHONS, and CHOS compounds, most likely resulting from anthropogenic inputs from upstream. Only 194 of these molecules were detected in the seawater end member after transporting to the sea, suggesting that the YRE served as a 'filter' of DOM. However, the flood enhances the transport of a group of terrigenous DOM, that is resistant to photodegradation and biodegradation. As a result, YRE experienced ~1.6 times higher terrigenous DOC flux than high discharge period. Considering the increased frequency of future floods, our study provides a preliminary basis for further research on how floods affect the composition and characteristics of estuarine DOM. With the help of the FT-ICR MS technique, we can now better understand the dynamic of DOM composition and characteristics in large river estuaries.

16.
Water Res ; 249: 120942, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38043348

RESUMO

Estuaries are hotspots where terrestrially originated dissolved organic matter (DOM) is modified in molecular composition before entering marine environments. However, very few research has considered nitrogen (N) modifications of DOM molecules in estuaries, limiting our understanding of dissolved organic nitrogen (DON) cycling and the associated carbon cycling in estuaries. This study integrated optical, stable isotopes (δ15N and δ13C) and molecular composition (FT-ICR MS) to characterize the transformation of DOM in the Yangtze River Estuary. Both concentration of dissolved organic carbon (DOC) and DON decreased with increasing salinity, while their δ13C and δ15N increased with the increasing salinity. A significant positive correlation was found between δ15N and δ13C during the transportation of DOM to marginal seas, indicating that the behavior of both DOC and DON are primarily controlled by the mixing of freshwater and the seawater in the YRE. During the mixing process, the DON addition was observed using the conservative mixing curves. In the view of molecular composition, DOM molecules became more aromatic as the number of N atoms increased. Spearman correlations reveal that DOM molecules with fewer N atoms exhibited a higher enrichment in protein-like components, while those with more N atoms were more enriched in humic-like components. In addition, the δ15N and δ13C tended to increase as the N content of DOM decreased. Therefore, DON molecules with fewer N atoms were likely to be transformed into those with more N atoms based on the isotopic fractionation theory. This study establishes a linkage between the molecular composition and the δ15N of DOM, and discovers the N transformation pattern within DOM molecules during the transportation to marginal seas.


Assuntos
Matéria Orgânica Dissolvida , Nitrogênio , Isótopos de Nitrogênio/análise , Oceanos e Mares , Nitrogênio/análise , Estuários , Rios/química
17.
Sci Total Environ ; 912: 168915, 2024 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-38030000

RESUMO

Rare earth elements (REEs) are important to enhance agricultural productivity. The utilization of phytoremediation as a green technology for addressing heavy metal (HMs) contamination in soil and wastewater has gained significant attention. In our research, we conducted indoor hydroponic experiments to examine the impacts of lanthanum (La) on the growth and enrichment capacity of Solanum nigrum L. (S. nigrum). S. nigrum was cultivated in 10 mg·L-1 of cadmium (Cd), 25 mg·L-1 of lead (Pb), and a mixture of both (5 mg·L-1 Cd + 15 mg·L-1 Pb). Additionally, S. nigrum were subjected to foliar spray or hydroponic supplementation of La(III). The treatment with La(III) significantly increased total fresh weight by 17.82 % to 42.20 %, compared to the treatment without La(III). Furthermore, La(III) facilitated the endocytosis of roots and enhanced Cd2+ flux ranging from 15.64 % to 75.99 % when compared to the treatment without La(III). Foliar and hydroponic application of La(III) resulted in an increase in the translocation factors (TF) in plants of Cd and Pb compared to treatments without La(III). These findings can offer valuable insights into the potential of La(III) to enhance the phytoremediation of soil or wastewater polluted with compounds.


Assuntos
Metais Pesados , Poluentes do Solo , Solanum nigrum , Cádmio/análise , Lantânio , Chumbo/toxicidade , Biodegradação Ambiental , Águas Residuárias , Poluentes do Solo/análise , Metais Pesados/análise , Solo/química , Endocitose
18.
Sci Total Environ ; 913: 169282, 2024 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-38141989

RESUMO

Coastal wetlands play a vital role in mitigating climate change, yet the characteristics of buried organic carbon (OC) and carbon cycling are limited due to difficulties in assessing the composition of OC from different sources (allochthonous vs. autochthonous). In this study, we analyzed the total organic carbon (TOC) to total nitrogen (TN) ratio (C/N), stable carbon isotope (δ13C) composition, and n-alkane content to distinguish different sources of OC in the surface sediments of the coastal wetlands on the western coast of the Bohai Sea. The coupling of the C/N ratio with δ13C and n-alkane biomarkers has been proved to be an effective tool for revealing OC sources. The three end-member Bayesian mixing model based on coupling C/N ratios with δ13C showed that the sedimentary OC was dominated by the contribution of terrestrial particulate organic matter (POM), followed by freshwater algae and marine phytoplankton, with relative contributions of 47 ± 21 %, 41 ± 18 % and 12 ± 17 %, respectively. The relative contributions of terrestrial plants, aquatic macrophytes and marine phytoplankton assessed by n-alkanes were 56 ± 8 %, 35 ± 9 % and 9 ± 5 % in the study area, respectively. The relatively high salinity levels and strong hydrodynamic conditions of the Beidagang Reservoir led to higher terrestrial plants source and lower aquatic macrophytes source than these of Qilihai Reservoir based on the assessment of n-alkanes. Both methods showed that sedimentary OC was mainly derived from terrestrial sources (plant-dominated), suggesting that vegetation plays a crucial role in storing carbon in coastal wetlands, thus, the coastal vegetation management needs to be strengthened in the future. Our findings provide insights into the origins and dynamics of OC in coastal wetlands on the western coast of the Bohai Sea and a significant scientific basis for future monitoring of the blue carbon budget balance in coastal wetlands.

19.
Sci Total Environ ; 908: 168374, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-37956851

RESUMO

Cadmium (Cd) and lead (Pb) accumulate easily in leafy vegetables and can harm human health. Lanthanum (La) have been used to improve agricultural yield and quality, but the effect of La application on Cd/Pb enrichment in leafy vegetables remains incomplete currently. A previous study reported that the endocytosis in lettuce leaf cells can be activated by La, leading to an increase in Pb accumulation in lettuce leaves. However, it has not been investigated whether foliar application of La enhances root cellular endocytosis and promotes its uptake of Cd and Pb. In this study, the influence of La on the uptake of Cd and Pb, Cd bioaccessibility, and the safety risks of cultivating lettuce under Cd and Pb stress were explored. It was found that La increased Cd (16-30 % in shoot, 16-34 % in root) and Pb (25-29 % in shoot, 17-23 % in root) accumulation in lettuce. The increased accumulation of Cd and Pb could be attributed to La-enhanced endocytosis. Meanwhile, La enhanced the toxicity of both Cd and Pb, inhibited lettuce growth, and aggravated the damage to the photosynthetic and antioxidant systems. Finally, gastrointestinal simulation experiments showed that La increased the Cd bioaccessibility in both gastric and intestinal phase by 7-108 % and 9-87 %, respectively. These results offer valuable insights into the safety of REEs for agricultural applications.


Assuntos
Cádmio , Poluentes do Solo , Humanos , Cádmio/análise , Lactuca , Lantânio/toxicidade , Chumbo/toxicidade , Verduras , Endocitose , Poluentes do Solo/análise , Solo
20.
Life (Basel) ; 13(10)2023 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-37895449

RESUMO

Ants (Formicidae) are the most diverse eusocial insects in Hymenoptera, distributed across 17 extant subfamilies grouped into 3 major clades, the Formicoid, Leptanilloid, and Poneroid. While the mitogenomes of Formicoid ants have been well studied, there is a lack of published data on the mitogenomes of Poneroid ants, which requires further characterization. In this study, we first present three complete mitogenomes of Poneroid ants: Paraponera clavata, the only extant species from the subfamily Paraponerinae, and two species (Harpegnathos venator and Buniapone amblyops) from the Ponerinae subfamily. Notable novel gene rearrangements were observed in the new mitogenomes, located in the gene blocks CR-trnM-trnI-trnQ-ND2, COX1-trnK-trnD-ATP8, and ND3-trnA-trnR-trnN-trnS1-trnE-trnF-ND5. We reported the duplication of tRNA genes for the first time in Formicidae. An extra trnQ gene was identified in H. venator. These gene rearrangements could be explained by the tandem duplication/random loss (TDRL) model and the slipped-strand mispairing model. Additionally, one large duplicated region containing tandem repeats was identified in the control region of P. clavata. Phylogenetic analyses based on protein-coding genes and rRNA genes via maximum likelihood and Bayes methods supported the monophyly of the Poneroid clade and the sister group relationship between the subfamilies Paraponerinae and Amblyoponinae. However, caution is advised in interpreting the positions of Paraponerinae due to the potential artifact of long-branch attraction.

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