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1.
Small ; : e2400033, 2024 Mar 03.
Article in English | MEDLINE | ID: mdl-38431941

ABSTRACT

Reticular heterojunctions on the basis of metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) have sparked considerable interest in recent research endeavors, which nevertheless have seldom been studied in optoelectronic biosensing. In this work, its utilization for organic photoelectrochemical transistor (OPECT) detection of the important cancer biomarker of neuron-specific enolase (NSE) is reported. A MOF@COF@CdS quantum dots (QDs) heterojunction is rationally designed to serve as the photogating module against the polymeric channel. Linking with a sandwich complexing event, target-dependent alternation of the photogate is achieved, leading to the changed photoelectric conversion efficiency as indicated by the amplified OPECT signals. The proposed assay demonstrates good analytical performance in detecting NSE, featuring a linear detection range from 0.1 pg mL-1 to 100 ng mL-1 , with a detection limit of 0.033 pg mL-1 .

2.
Environ Sci Technol ; 58(14): 6370-6380, 2024 Apr 09.
Article in English | MEDLINE | ID: mdl-38497719

ABSTRACT

The discovery of the significant lethal impacts of the tire additive transformation product N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine quinone (6PPD-Q) on coho salmon has garnered global attention. However, the bioaccumulation and trophic transfer of tire additives and their transformation products (TATPs) within food webs remain obscure. This study first characterized the levels and compositions of 15 TATPs in the Pearl River Estuary, estimated their bioaccumulation and trophic transfer potential in 21 estuarine species, and identified priority contaminants. Our observations indicated that TATPs were prevalent in the estuarine environment. Eight, six, seven, and 10 TATPs were first quantified in the shrimp, sea cucumber, snail, and fish samples, with total mean levels of 45, 56, 64, and 67 ng/g (wet weight), respectively. N,N'-Diphenyl-p-phenylenediamine (DPPD) and N,N'-bis(2-methylphenyl)-1,4-benzenediamine (DTPD) exhibited high bioaccumulation. Significant biodilution was only identified for benzothiazole, while DPPD and DTPD displayed biomagnification trends based on Monte Carlo simulations. The mechanisms of bioaccumulation and trophodynamics of TATPs could be explained by their chemical hydrophobicity, molecular mass, and metabolic rates. Based on a multicriteria scoring technique, DPPD, DTPD, and 6PPD-Q were characterized as priority contaminants. This work emphasizes the importance of biomonitoring, particularly for specific hydrophobic tire additives.


Subject(s)
Food Chain , Phenylenediamines , Water Pollutants, Chemical , Animals , Bioaccumulation , Environmental Monitoring , Water Pollutants, Chemical/analysis
3.
Environ Int ; 184: 108478, 2024 Feb.
Article in English | MEDLINE | ID: mdl-38330749

ABSTRACT

Estuaries serve as crucial filters for land-based pollutants to the open sea, but there is a lack of information on the migration and fate of organophosphate flame retardants (OPFRs) within estuaries. This study focused on the Pearl River Estuary (PRE) by examining the co-occurrence of OPFRs and their metabolites and quantifying their transport fluxes using a mass balance model. The seawater concentrations of OPFRs and their metabolites exhibited significant seasonal variations (p < 0.01), while the sediment concentrations of OPFRs reflected the long-term distributional equilibrium in the PRE. The concentration of Σ9OPFRs in seawater showed a relentless dilution from the entrance to the offshore region in the normal and wet seasons, which was significantly in accordance with the gradients of pH, dissolved oxygen (DO), and salinity (p < 0.05). Furthermore, horizontal migration dominated the transport of OPFRs, and the inventory assessment revealed that both the water column and sediment were important reservoirs in the PRE. According to the estimated fluxes from the mass balance model, riverine input emerged as the principal pathway for OPFR entry into the PRE (1.55 × 105, 6.28 × 104, and 9.00 × 104 kg/yr in the normal, dry and wet seasons, respectively), whereas outflow to the open sea predominantly determined the main fates of the OPFRs. The risk quotient (RQ) results showed that EHDPHP (0.835) in water posed medium ecological risk, while other OPFRs and metabolites presented relatively lower risk (RQ < 0.1). The risk control effects were evaluated through scenario simulations of mathematical fitting between controllable source factors and the RQ of risky OPFR. The risk of EHDPHP in the PRE could be effectively reduced by restricting its concentrations in entrance region (<9.31, 8.67, and 12.7 ng/L in the normal, dry and wet seasons, respectively) of the PRE. This research offers foundational insights into environmental management and pollution control strategies for emerging pollutants in estuaries.


Subject(s)
Environmental Pollutants , Flame Retardants , Water Pollutants, Chemical , Organophosphates/analysis , Estuaries , Flame Retardants/analysis , Rivers , Water Pollutants, Chemical/analysis , Water , China
4.
J Hazard Mater ; 465: 133390, 2024 Mar 05.
Article in English | MEDLINE | ID: mdl-38163409

ABSTRACT

Tetrabromobisphenol A (TBBPA) analogues have been investigated for their prevalent occurrence in environments and potential hazardous effects to humans and wildlife; however, there is still limited knowledge regarding their toxicokinetics and trophic transfer in aquatic food chains. Using a developed toxicokinetic model framework, we quantified the bioaccumulation, biotransformation and trophic transfer of tetrabromobisphenol S (TBBPS) and tetrabromobisphenol A di(allyl ether) (TBBPA-DAE) during trophic transfer from brine shrimp (Artemia salina) to zebrafish (Danio rerio). The results showed that the two TBBPA analogues could be readily accumulated by brine shrimp, and the estimated bioconcentration factor (BCF) value of TBBPS (5.68 L kg-1 ww) was higher than that of TBBPA-DAE (1.04 L kg-1 ww). The assimilation efficiency (AE) of TBBPA-DAE in zebrafish fed brine shrimp was calculated to be 16.3%, resulting in a low whole-body biomagnification factor (BMF) in fish (0.684 g g-1 ww). Based on the transformation products screened using ultra-high-performance liquid chromatograph-high resolution mass spectrometry (UPLC-HRMS), oxidative debromination and hydrolysis were identified as the major transformation pathways of TBBPS, while the biotransformation of TBBPA-DAE mainly took place through ether bond breaking and phase-II metabolism. Lower accumulation of TBBPA as a metabolite than its parent chemical was observed in both brine shrimp and zebrafish, with metabolite parent concentration factors (MPCFs) < 1. The investigated BCFs for shrimp of the two TBBPA analogues were only 3.77 × 10-10 - 5.59 × 10-3 times of the theoretical Kshrimp-water based on the polyparameter linear free energy relationships (pp-LFERs) model, and the BMF of TBBPA-DAE for fish was 0.299 times of the predicted Kshrimp-fish. Overall, these results indicated the potential of the trophic transfer in bioaccumulation of specific TBBPA analogues in higher trophic-level aquatic organisms and pointed out biotransformation as an important mechanism in regulating their bioaccumulation processes. ENVIRONMENTAL IMPLICATION: The internal concentration of a pollutant in the body determines its toxicity to organisms, while bioaccumulation and trophic transfer play important roles in elucidating its risks to ecosystems. Tetrabromobisphenol A (TBBPA) analogues have been extensively investigated for their adverse effects on humans and wildlife; however, there is still limited knowledge regarding their toxicokinetics and trophic transfer in aquatic food chains. This study investigated the bioaccumulation, biotransformation and trophic transfer of TBBPS and TBBPA-DAE in a simulated di-trophic food chain. This state-of-art study will provide a reference for further research on this kind of emerging pollutant in aquatic environments.


Subject(s)
Environmental Pollutants , Perciformes , Polybrominated Biphenyls , Water Pollutants, Chemical , Animals , Humans , Food Chain , Bioaccumulation , Ecosystem , Zebrafish/metabolism , Biotransformation , Perciformes/metabolism , Environmental Pollutants/analysis , Ethers , Water Pollutants, Chemical/analysis
5.
Helicobacter ; 29(1): e13038, 2024.
Article in English | MEDLINE | ID: mdl-37983899

ABSTRACT

BACKGROUND: To investigate the antibiotic resistance of Helicobacter pylori (H. pylori) strains to clarithromycin, metronidazole, amoxicillin, levofloxacin, furazolidone, and tetracycline in Chinese children. MATERIALS AND METHODS: This multicenter, retrospective study was conducted from January 2016 through May 2023. Gastric mucosa biopsies were obtained from pediatric participants who underwent upper gastrointestinal endoscopy at 96 hospitals in northern, southwestern, and southeastern China. The susceptibility of H. pylori to six commonly used antibiotics was determined by agar dilution method. RESULTS: Among the 3074 H. pylori isolates, 36.7% were resistant to clarithromycin, 77.3% to metronidazole, 16.6% to levofloxacin, and 0.3% to amoxicillin. No strains were detected to be resistant to furazolidone or tetracycline. During the 8-year study period, resistance to clarithromycin and metronidazole showed a significant upward trend, while the resistance pattern of the other antibiotics demonstrated a slight but nonsignificant fluctuation. Significant regional differences were found in the distribution of clarithromycin resistance among the northern (66.0%), southwestern (48.2%), and southeastern (34.6%) regions. The metronidazole resistance rate was significantly lower in the southeastern coastal region (76.3%) than in the other two regions (88.2% in the north and 87.7% in the southwest). Multi-drug resistance for two or more antibiotics was detected in 36.3% of the H. pylori strains, and the predominant multi-resistance pattern was the dual resistance to clarithromycin and metronidazole. CONCLUSIONS: The prevalence of H. pylori resistance to clarithromycin and metronidazole is rather high in Chinese children and has been increasing over time. A relatively high resistance rate to levofloxacin was also noticed in children, while almost all strains were susceptible to amoxicillin, furazolidone, and tetracycline. It will be of great clinical significance to continuously monitor the antibiotic-resistance patterns of H. pylori in the pediatric population.


Subject(s)
Helicobacter Infections , Helicobacter pylori , Child , Humans , Clarithromycin , Metronidazole/pharmacology , Levofloxacin , Helicobacter Infections/epidemiology , Helicobacter Infections/drug therapy , Furazolidone , Retrospective Studies , Microbial Sensitivity Tests , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Amoxicillin/pharmacology , Tetracycline , Drug Resistance, Microbial , China/epidemiology , Drug Resistance, Bacterial
6.
J Hazard Mater ; 465: 133088, 2024 03 05.
Article in English | MEDLINE | ID: mdl-38016320

ABSTRACT

The substantial utilization of antibiotics causes their "pseudo-persistence" in offshore environments. Published studies on antibiotic surveillance in food webs have primarily emphasized on parent forms; however, the compositions and concentrations of conjugated antibiotics in aquatic organisms remain largely unexplored. This study systematically examined the distribution characteristics and trophodynamics of free antibiotics and their conjugated forms in an estuarine food web. Total antibiotic levels differed insignificantly between the surface and bottom waters. The total mean values of free antibiotics in crabs, fish, shrimps, sea cucumbers, and snails varied from 0.77 to 1.4 ng/g (wet weight). The numbers and values of antibiotics rose in these biological samples after enzymatic hydrolysis. Conjugated antibiotics accounted for 23.8-76.9% of the total antibiotics in the biological samples, revealing that conjugated forms play a non-negligible role in aquatic organisms. More number of antibiotics exhibited bioaccumulation capabilities after enzymatic hydrolysis. In the food web, the free forms of anhydroerythromycin and conjugated forms of trimethoprim and ciprofloxacin underwent trophic dilution, whereas the free forms of trimethoprim and conjugated forms of ofloxacin underwent trophic amplification. The present work provides new insights into the bioaccumulation and trophic transfer of free and conjugated antibiotics in food webs.


Subject(s)
Food Chain , Water Pollutants, Chemical , Animals , Anti-Bacterial Agents/analysis , Bioaccumulation , Multimedia , Water Pollutants, Chemical/analysis , Aquatic Organisms , Fishes , Trimethoprim , Environmental Monitoring , China
7.
Environ Sci Technol ; 57(31): 11476-11488, 2023 08 08.
Article in English | MEDLINE | ID: mdl-37462611

ABSTRACT

Ingestion is a major exposure route for hydrophobic organic pollutants in fish, but the microbial transformation and estrogenic modification of the novel plastic additives by the gut microbiota of fish remain obscure. Using an in vitro approach, we provide evidence that structure-related transformation of various plastic additives by the gastric and intestinal (GI) microbiota from crucian carp, with the degradation ratio of bisphenols and triphenyl phosphate faster than those of brominated compounds. The degradation kinetics for these pollutants could be limited by oxygen and cometabolic substrates (i.e., glucose). The fish GI microbiota could utilize the vast majority of carbon sources in a Biolog EcoPlate, suggesting their high metabolic potential and ability to transform various organic compounds. Unique microorganisms associated with transformation of the plastic additives including genera of Citrobacter, Klebsiella, and some unclassified genera in Enterobacteriaceae were identified by combining high-throughput genetic analyses and metagenomic analyses. Through identification of anaerobic transformation products by high-resolution mass spectrometry, alkyl-cleavage was found the common transformation mechanism, and hydrolysis was the major pathway for ester-containing pollutants. After anaerobic incubation, the estrogenic activities of triphenyl phosphate and bisphenols A, F, and AF declined, whereas that of bisphenol AP increased.


Subject(s)
Carps , Environmental Pollutants , Gastrointestinal Microbiome , Animals , Plastics , Estrone
8.
Sci Total Environ ; 895: 165190, 2023 Oct 15.
Article in English | MEDLINE | ID: mdl-37385506

ABSTRACT

The distribution and transport of atmospheric microplastics (AMPs) have raised concerns regarding their potential effects on the environment and human health. Although previous studies have reported the presence of AMPs at ground level, there is a lack of comprehensive understanding of their vertical distribution in urban environments. To gain insight into the vertical profile of AMPs, field observations were conducted at four different heights (ground level, 118 m, 168 m and 488 m) of the Canton Tower in Guangzhou, China. Results showed that the profiles of AMPs and other air pollutants had similar layer distribution patterns, although their concentrations differed. The majority of AMPs were composed of polyethylene terephthalate and rayon fibers ranging from 30 to 50 µm. As a result of atmospheric thermodynamics, AMPs generated at ground level were only partially transported upward, leading to a decrease in their abundance with increasing altitude. The study found that the stable atmospheric stability and lower wind speed between 118 m and 168 m resulted in the formation of a fine layer where AMPs tended to accumulate instead of being transported upward. This study for the first time delineated the vertical profile of AMPs within the atmospheric boundary layer, providing valuable data for understanding the environmental fate of AMPs.

9.
ACS Appl Mater Interfaces ; 15(25): 30394-30401, 2023 Jun 28.
Article in English | MEDLINE | ID: mdl-37327481

ABSTRACT

The separation of CO2 from the industrial post-combustion flue gas is of great importance to reduce the increasingly serious greenhouse effect, yet highly challenging due to the extremely high stability, low cost, and high separation performance requirements for adsorbents under the practical operating conditions. Herein, we report a robust squarate-cobalt metal-organic framework (MOF), FJUT-3, featuring an ultra-small 1D square channel decorated with -OH groups, for CO2/N2 separation. Remarkably, FJUT-3 not only has excellent stability under harsh chemical conditions but also presents low-cost property for scale-up synthesis. Moreover, FJUT-3 shows excellent CO2 separation performance under various humid and temperature conditions confirmed by the transient breakthrough experiments, thus enabling FJUT-3 with adequate potentials for industrial CO2 capture and removal. The distinct CO2 adsorption mechanism is well elucidated by theoretical calculations, in which the hierarchical C···OCO2, C-O···CCO2, and O-H···OCO2 interactions play a vital synergistic role in the selective CO2 adsorption process.

10.
Materials (Basel) ; 16(8)2023 Apr 12.
Article in English | MEDLINE | ID: mdl-37109874

ABSTRACT

Porous high-entropy ceramics are a new alternative material for thermal insulation. Their better stability and low thermal conductivity are due to lattice distortion and unique pore structures. In this work, rare-earth-zirconate ((La0.25Eu0.25Gd0.25Yb0.25)2(Zr0.75Ce0.25)2O7) porous high-entropy ceramics were fabricated by a tert-butyl alcohol (TBA)-based gel-casting method. The regulation of pore structures was realized through changing different initial solid loadings. The XRD, HRTEM, and SAED results showed that the porous high-entropy ceramics had a single fluorite phase without impurity phases, exhibiting high porosity (67.1-81.5%), relatively high compressive strength (1.02-6.45 MPa) and low thermal conductivity (0.0642-0.1213 W/(m·K)) at room temperature. Porous high-entropy ceramics with 81.5% porosity demonstrated excellent thermal properties, showing a thermal conductivity of 0.0642 W/(m·K) at room temperature and 0.1467 W/(m·K) at 1200 °C. The unique pore structure with a micron size contributed to their excellent thermal insulating performance. The present work provides the prospect that rare-earth-zirconate porous high-entropy ceramics with tailored pore structures are expected to be thermal insulation materials.

11.
JACC Cardiovasc Interv ; 16(5): 558-570, 2023 03 13.
Article in English | MEDLINE | ID: mdl-36922042

ABSTRACT

BACKGROUND: Procedural success and clinical outcomes after transcatheter aortic valve replacement (TAVR) have improved, but residual aortic regurgitation (AR) and new permanent pacemaker implantation (PPI) rates remain variable because of a lack of uniform periprocedural management and implantation. OBJECTIVES: The Optimize PRO study evaluates valve performance and procedural outcomes using an "optimized" TAVR care pathway and the cusp overlap technique (COT) in patients receiving the Evolut PRO/PRO+ (Medtronic) self-expanding valves. METHODS: Optimize PRO, a nonrandomized, prospective, postmarket study conducted in the United States, Canada, Europe, Middle East, and Australia, is enrolling patients with severe symptomatic aortic stenosis and no pre-existing pacemaker. Sites follow a standardized TAVR care pathway, including early discharge and a conduction disturbance management algorithm, and transfemoral deployment using the COT. RESULTS: A total of 400 attempted implants from the United States and Canada comprised the main cohort of this second interim analysis. The mean age was 78.7 ± 6.6 years, and the mean Society of Thoracic Surgeons predictive risk of mortality was 3.0 ± 2.4. The median length of stay was 1 day. There were no instances of moderate or severe AR at discharge. At 30 days, all-cause mortality or stroke was 3.8%, all-cause mortality was 0.8%, disabling stroke was 0.7%, hospital readmission was 10.1%, and cardiovascular rehospitalization was 6.1%. The new PPI rate was 9.8%, 5.8% with 4-step COT compliance. In the multivariable model, right bundle branch block and the depth of the implant increased the risk of PPI, whereas using the 4-step COT lowered 30-day PPI. CONCLUSIONS: The use of the TAVR care pathway and COT resulted in favorable clinical outcomes with no moderate or severe AR and low PPI rates at 30 days while facilitating early discharge and reproducible outcomes across various sites and operators. (Optimize PRO; NCT04091048).


Subject(s)
Aortic Valve Insufficiency , Aortic Valve Stenosis , Heart Valve Prosthesis , Stroke , Transcatheter Aortic Valve Replacement , Humans , United States , Aged , Aged, 80 and over , Transcatheter Aortic Valve Replacement/adverse effects , Aortic Valve/diagnostic imaging , Aortic Valve/surgery , Aortic Valve Stenosis/diagnostic imaging , Aortic Valve Stenosis/surgery , Aortic Valve Stenosis/complications , Critical Pathways , Prospective Studies , Risk Factors , Treatment Outcome , Aortic Valve Insufficiency/etiology , Heart Valve Prosthesis/adverse effects
12.
Water Res ; 235: 119913, 2023 May 15.
Article in English | MEDLINE | ID: mdl-36996753

ABSTRACT

Steroids have attracted particular attention as environmental contaminants because of their severe endocrine-disrupting effects. Previous studies have predominantly focused on parent steroids; however, the levels and proportions of the free and conjugated forms of their metabolites remain largely unclear, especially in food webs. Here, we first characterized the free and conjugated forms of parent steroids and their metabolites in 26 species in an estuarine food web. The steroids were dominated by their metabolites in water samples, whereas parent compounds were predominant in sediment samples. The total mean steroid concentrations in the biota samples that underwent non-enzymatic hydrolysis decreased in the following order: crabs (27 ng/g) > fish (5.9 ng/g) > snails (3.4 ng/g) > shrimps and sea cucumbers (1.2 ng/g); and those in the biota samples that underwent enzymatic hydrolysis decreased in the following order: crabs (57 ng/g) > snails (9.2 ng/g) > fish (7.9 ng/g) > shrimps and sea cucumbers (3.5 ng/g). The proportion of metabolites in the enzymatic hydrolysis biota samples was higher (38-79%) than that (2.9-65%) in non-enzymatic ones, indicating that the free and conjugated forms of metabolites in aquatic organisms were not negligible. Most synthetic steroids were either bioaccumulative or highly bioaccumulative. Importantly, in the invertebrate food web, 17α-methyltestosterone was biomagnified, while 17ß-boldenone underwent trophic dilution. Although the estuarine water had a median ecological risk level, the health risks via aquatic product consumption were very low. This study provides novel insights into the composition and trophic transfer of steroids in an estuarine food web for the first time and highlights that free and conjugated metabolites should receive more attention, particularly in biota samples.


Subject(s)
Food Chain , Water Pollutants, Chemical , Animals , Environmental Monitoring , Water Pollutants, Chemical/analysis , Fishes , Steroids/metabolism , Water , China
13.
Environ Pollut ; 326: 121499, 2023 Jun 01.
Article in English | MEDLINE | ID: mdl-36972813

ABSTRACT

Steroids have attracted concern worldwide because of their potential carcinogenicity and severe adverse effects on aquatic organisms. However, the contamination status of various steroids, particularly their metabolites, at the watershed level remains unknown. This was the first study to employ field investigations to elucidate the spatiotemporal patterns, riverine fluxes, and mass inventories, and conduct a risk assessment of 22 steroids and their metabolites. This study also developed an effective tool for predicting the target steroids and their metabolites in a typical watershed based on the fugacity model combined with a chemical indicator. Thirteen steroids in the river water and seven steroids in sediments were identified with total concentrations of 1.0-76 ng/L and

Subject(s)
Water Pollutants, Chemical , Water Pollutants, Chemical/analysis , Environmental Monitoring/methods , Seasons , Water , Aquatic Organisms , Rivers/chemistry , Steroids , China , Geologic Sediments/chemistry
14.
J Phys Condens Matter ; 35(14)2023 Feb 13.
Article in English | MEDLINE | ID: mdl-36731172

ABSTRACT

At present, chips urgently need breakthrough development in the power consumption and integration. The chip integrates billions or even tens of billions of electronic components, such as field effect transistor, diode and so on. Therefore, the research and development of new low-power electronic components with smaller size is an effective method to reduce chip power consumption and improve chip integration. In this paper, the ferroelectric field effect transistor (Fe-FET) based on two-dimensional heterostructuresα-In2Se3/ZnSe is proposed. Based on the first principle, the program will analyze the stability and band structure ofα-In2Se3/ZnSe under different stacking modes. In the heterojunction, the microphysical mechanism of ferroelectric polarization affecting the electronic structure is revealed from the aspects of charge transfer at the interface and the asymmetric surfaces with different work function. Combined with the non-equilibrium Green's function transport theory, the transport properties of Fe-FET based on theirα-In2Se3/ZnSe will be studied. The application will provide sufficient theoretical support for research and development of the device based onα-In2Se3/ZnSe structure.

15.
Environ Sci Technol ; 57(9): 3549-3561, 2023 03 07.
Article in English | MEDLINE | ID: mdl-36826812

ABSTRACT

The accumulation and trophodynamics of organophosphate flame retardants (OPFRs) and their metabolites were investigated in the estuarine food web of the Pearl River, China. The mean ∑OPFR concentration among the investigated species increased in the following order: fish [431 ± 346 ng/g lipid weight (lw)] < snail (1310 ± 621 ng/g lw) < shrimp (1581 ± 1134 ng/g lw) < crab (1744 ± 1397 ng/g lw). The di-alkyl phosphates (DAPs) of di-(n-butyl) phosphate (DNBP), bis(2-butoxyethyl) phosphate (BBOEP), and diphenyl phosphate (DPHP) were the most abundant metabolites, with concentrations same as or even higher than their corresponding parent compounds. The log bioaccumulation factors for most OPFRs were lower than 3.70, and significant biomagnification was only found for trisphenyl phosphate [TPHP, with the trophic magnification factors (TMFs) > 1]. The TMFs of OPFRs, except for TPHP and tributyl phosphate had a positive correlation with lipophilicity (log KOW, p ≤ 0.05) and a negative correlation with the biotransformation rate (log KM, p ≤ 0.05). The mean TMF > 1 was observed for all of the OPFR metabolites based on the bootstrap regression method. The "pseudo-biomagnification" of OPFR metabolites might be attributed to the biotransformation of OPFRs in organisms at high trophic levels.


Subject(s)
Flame Retardants , Food Chain , Animals , Flame Retardants/analysis , Bioaccumulation , Rivers , Organophosphates , China , Phosphates , Environmental Monitoring
16.
Mol Ther Nucleic Acids ; 31: 88-104, 2023 Mar 14.
Article in English | MEDLINE | ID: mdl-36618268

ABSTRACT

Rheumatoid arthritis (RA) is an inflammatory disease that leads to disability; however, existing therapies are still unsatisfactory. Activated fibroblast-like synoviocytes (FLSs) play an essential role in synovitis formation and joint destruction in RA. The Hedgehog signaling pathway is aberrantly activated and contributes to the aggressive phenotype of RA-FLSs. However, it remains uncertain whether inhibiting Smoothened (SMO), a critical component of the Hedgehog signaling pathway, is an effective treatment for RA. Here, we design a series of small interfering RNAs (siRNAs) that specifically target the SMO gene. With precise chemical modifications, siRNAs' efficacy and stability are significantly improved, and the off-target effects are minimized. The optimized chemically modified siRNA (si-S1A3-Chol) decreases RA-FLS proliferation and invasiveness without the transfection reagent. Furthermore, si-S1A3-Chol injected intra-articularly effectively alleviates joint destruction and improves motor function in collagen-induced arthritis mouse models. Consequently, our results demonstrate that chemically modified siRNA targeting the Hedgehog signaling pathway may be a potential therapy for RA.

17.
Sci Total Environ ; 869: 161839, 2023 Apr 15.
Article in English | MEDLINE | ID: mdl-36709905

ABSTRACT

Atmospheric microplastics (AMPs) have raised much concern for public health due to their potential for exposure. In this study, temporal distribution, characteristics and exposure risk of AMPs were studied in the urban area of Guangzhou, a metropolis in Southern China, and the washout effect of rainfall on AMPs was investigated. It was found that AMP abundances in Guangzhou were in a range of 0.01-0.44 items/m3, with higher abundance in the wet season (0.19 ± 0.01 items/m3) than in the dry season (0.15 ± 0.02 items/m3). The distribution of AMPs did not correspond to that of common air pollutants (e.g., PM2.5 and PM10), implying that their pollution sources might be distinct. In Guangzhou, a total of 1.26 × 1011 items AMPs are in the air every year, and annual inhalation exposure of adults was estimated to be in the range of 79.65-3.50 × 103 items. The annual deposition flux of AMPs is 65.94 ± 7.53 items/m2/d, and the deposition flux in the wet season (84.00 ± 6.95 items/m2/d) was much greater than that in the dry season (47.88 ± 8.35 items/m2/d). Furthermore, rainfall has an effective mechanism for removing AMPs from the atmosphere, with an average washout ratio of (19.39 ± 6.48) × 104 for rainfall washing AMPs out. Compared to moderate rain (2.5-10 mm/h) and heavy rain (10-50 mm/h), light rain (rainfall intensity <2.5 mm/h) had a better washout effect. This study contributes to the evaluation of AMP exposure risk and understanding of AMP environmental behavior and fate by providing long-term monitoring data on AMPs and quantifying the washout effect of rainfall on AMPs for the first time.


Subject(s)
Air Pollutants , Microplastics , Plastics , Air Pollutants/analysis , Atmosphere , China , Rain , Environmental Monitoring
18.
Environ Pollut ; 322: 121158, 2023 Apr 01.
Article in English | MEDLINE | ID: mdl-36716949

ABSTRACT

In recent years, microplastics (MPs) as emerging carriers for environmental pollutants have attracted increasing worldwide attention. However, the adsorption of heavy metals on MPs, especially for biodegradable MPs, has been still poorly understood in estuarine environments. In this study, we investigated the aging of biodegradable and conventional MPs in the Pearl River Estuary after long-term exposure and their impacts on the adsorption of heavy metals from seawater. The results showed that the changes in surface characteristics were more prominent on biodegradable MPs than on conventional MPs after aging. Both biodegradable and conventional MPs could adsorb heavy metals, and their adsorption capacities fluctuated greatly on different MPs and different exposure times. The adsorption capacities of Cu, Pb, and As on biodegradable MPs were higher than those on conventional MPs, whereas Mn, Cr, and Co had lower adsorption on biodegradable MPs after 9-12 months by inductively coupled plasma-mass spectrometry (ICP-MS). The aging characteristics (CI, O/C, and Xc) of MPs accounted for a contribution of 51.0% on heavy metal adsorption, while the environmental factors (temperature, salinity, pH, and heavy metal concentration) only contributed to 13.2%. Therefore, the present study can provide important evidence on the environmental behaviors and ecological risks of biodegradable and conventional MPs in estuarine systems.


Subject(s)
Metals, Heavy , Water Pollutants, Chemical , Microplastics/chemistry , Plastics , Adsorption , Rivers , Estuaries , Water Pollutants, Chemical/analysis , Metals, Heavy/analysis , China
19.
Toxicol Appl Pharmacol ; 458: 116326, 2023 01 01.
Article in English | MEDLINE | ID: mdl-36436566

ABSTRACT

Zinc finger protein 671 (ZNF671) has been described as a vital cancer inhibitor in multiple neoplasms, yet the functional roles of ZNF671 in colorectal carcinoma (CRC) remain unresolved. This project examined the possible link between ZNF671 and CRC. Lower levels of ZNF671 were observed in CRC tissue compared with noncancerous tissue, which were related to a worse survival rate in CRC patients. High methylation levels at the ZNF671 gene promoter region were shown in CRC tissue, which were inversely correlated with ZNF671 expression. Treatment with demethylation agents restored ZNF671 levels in CRC cell lines. Up-regulation of ZNF671 resulted in suppressive effects on the proliferative ability and metastatic potency of CRC cells. Moreover, the up-regulation of ZNF671 reinforced the chemosensitivity of CRC cells. A mechanism study determined ZNF671 to be a vital mediator of Notch signaling. The up-regulation of ZNF671 decreased the expression of Notch1 and lowered the levels of NICD, HES1, and HEY1. The overexpression of NICD1 diminished ZNF671-mediated antitumor effects. ZNF671 depletion reinforced Notch signaling, and Notch suppression reversed ZNF671-depletion-elicited protumor effects. Moreover, the overexpression of ZNF671 weakened the tumorigenicity of CRC cells in a xenograft model in vivo. In summary, ZNF671 exerts a cancer-inhibiting function in CRC via the deactivation of Notch signaling. Low ZNF671 levels caused by gene promoter hypermethylation contribute to the malignant transformation of CRC. This work underlines the interest of ZNF671 as a target candidate for exploiting novel anti-CRC therapies.


Subject(s)
Colorectal Neoplasms , Humans , Colorectal Neoplasms/drug therapy , Colorectal Neoplasms/genetics , Colorectal Neoplasms/metabolism , DNA Methylation , Signal Transduction , Zinc Fingers , Gene Expression Regulation, Neoplastic , Cell Line, Tumor , Tumor Suppressor Proteins/metabolism
20.
Mar Pollut Bull ; 186: 114399, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36495611

ABSTRACT

Microplastics are recognized as a newly emerging threat to marine organisms as they can be ingested and accumulated through multiple trophic levels. However, microplastic contamination and its potential risk assessment in coral reef fishes have been less addressed, particularly in remote ocean regions. In this study, microplastics in 167 samples of coral reef fish (a total of eighteen species) from the Xisha areas of the South China Sea were studied. There were fifteen species of coral reef fish contaminated by microplastics with an average occurrence rate of 29.3 %. The shape of microplastics in the fishes was mostly fibrous with small sizes (400-900 µm) and light colors (transparent and blue). The dominant types of microplastic polymers are polyamide and polyethylene terephthalate, accounting for 77 % and 11 % of microplastics in the fish body. There were generally more microplastics in the herbivorous fishes than the carnivorous ones. The highest microplastic abundance and occurrence was found in parrotfish due to its direct feeding on the microplastics-contaminated corals. In addition, there were much more microplastics in the gastrointestinal tracts than in the gills of the Xisha fishes. Microplastic abundance was found negatively correlated with the trophic level of the Xisha fishes supporting a stronger microplastic impact at lower levels of marine animals. Finally, a risk assessment using the polymer hazard index (PHI) revealed that microplastic contamination in the Xisha fishes was lower than those in the eutrophic coast. Our study provides new evidence for the widespread presence of microplastic contamination in the fishes of the remote Xisha coral reefs.


Subject(s)
Microplastics , Water Pollutants, Chemical , Animals , Coral Reefs , Plastics , Water Pollutants, Chemical/analysis , Environmental Monitoring , Polymers , Fishes , China
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