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1.
Materials (Basel) ; 17(10)2024 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-38793429

RESUMEN

Currently, coastal sandy soils face issues such as insufficient foundation strength, which has become one of the crucial factors constraining urban development. Geotechnical engineering, as a traditional discipline, breaks down disciplinary barriers, promotes interdisciplinary integration, and realizes the green ecological and low-carbon development of geotechnical engineering, which is highly important. Based on the "dual carbon" concept advocating a green and environmentally friendly lifestyle, Bacillus spores were utilized to induce calcium carbonate precipitation technology (MICP) to solidify coastal sandy soils, leveraging the rough-surface and low-permeability characteristics of silty soil. The mechanical-strength variations in the samples were explored through experiments, such as calcium carbonate generation rate tests, non-consolidated undrained triaxial shear tests, and scanning electron microscopy (SEM) experiments, to investigate the MICP solidification mechanism. The results indicate that by incorporating silty soil into sandy soil for MICP solidification, the calcium carbonate generation rates of the samples were significantly increased. With the increase in the silty-soil content, the enhancement range was 0.58-3.62%, with the maximum calcium carbonate generation rate occurring at a 5% content level. As the silty-soil content gradually increased from 1% to 5%, the peak deviator stress increased by 4.2-43.2%, enhancing the sample shear strength. Furthermore, the relationship between the internal-friction angle, cohesion, and shear strength further validates the enhancement of the shear strength. Silty soil plays roles in adsorption and physical filling during the MICP solidification process, reducing the inter-particle pores in sandy soil, increasing the compactness, providing adsorption sites, and enhancing the calcium carbonate generation rate, thereby improving the shear strength. The research findings can provide guidance for reinforcing poor coastal sandy-soil foundations in various regions.

2.
PLoS One ; 19(2): e0298537, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38408100

RESUMEN

BACKGROUND: Constipation is one of the common gastrointestinal complications after stroke. It not only aggravates the condition of stroke, but also brings huge medical burden to patients, and has a negative impact on the quality of life of patients. Auricular therapy, as a part of Chinese traditional acupuncture and moxibustion, has been found to be effective in the clinical treatment of constipation. However, no systematic review has investigated the efficacy and safety of auricular therapy in the treatment of post-stroke constipation. Therefore, the aim of this systematic review is to assess the effectiveness and safety of auricular therapy for post-stroke constipation. METHODS AND ANALYSIS: Eight electronic databases including PubMed, Cochrane Library/Cochrane Central Register of Controlled Trials, Web of Science, Embase, China National Knowledge Internet, Chinese Biomedical Literature Database, Wanfang, and VIP databases, will be searched for relevant studies published from inception to February 2023. Two reviewers will independently conduct research selection, data extraction, and evaluation of research quality. Only randomized controlled trials (RCTs) that assess the efficacy and safety of auricular therapy for the treatment of post-stroke constipation will be included in this study. We will use the Cochrane risk of bias assessment tool to evaluate the methodological qualities (including bias risk). If possible, a meta-analysis will be performed after screening. RESULTS: This study may provide high-quality evidence for the efficacy and safety of auricular therapy in treating post-stroke constipation. CONCLUSION: The conclusions of our study will provide an evidence to judge whether auricular therapy is an effective and safe intervention for patients with post-stroke constipation. ETHICS AND DISSEMINATION: Ethical approval is not required, as this study was based on a review of published research. This review will be published in a peer-reviewed journal and disseminated electronically and in print. TRIAL REGISTRATION: Registration number: PROSPERO CRD42023402242.


Asunto(s)
Terapia por Acupuntura , Moxibustión , Accidente Cerebrovascular , Humanos , Revisiones Sistemáticas como Asunto , Metaanálisis como Asunto , Moxibustión/métodos , Estreñimiento/etiología , Estreñimiento/terapia , Accidente Cerebrovascular/complicaciones , Accidente Cerebrovascular/terapia , Proyectos de Investigación , Literatura de Revisión como Asunto , Ensayos Clínicos Controlados Aleatorios como Asunto
3.
Front Oncol ; 13: 1006172, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37007144

RESUMEN

Objectives: To develop and validate a CT-based radiomics nomogram that can provide individualized pretreatment prediction of the response to platinum treatment in small cell lung cancer (SCLC). Materials: A total of 134 SCLC patients who were treated with platinum as a first-line therapy were eligible for this study, including 51 patients with platinum resistance (PR) and 83 patients with platinum sensitivity (PS). The variance threshold, SelectKBest, and least absolute shrinkage and selection operator (LASSO) were applied for feature selection and model construction. The selected texture features were calculated to obtain the radiomics score (Rad-score), and the predictive nomogram model was composed of the Rad-score and the clinical features selected by multivariate analysis. Receiver operating characteristic (ROC) curves, calibration curves, and decision curves were used to assess the performance of the nomogram. Results: The Rad-score was calculated using 10 radiomic features, and the resulting radiomics signature demonstrated good discrimination in both the training set (area under the curve [AUC], 0.727; 95% confidence interval [CI], 0.627-0.809) and the validation set (AUC, 0.723; 95% CI, 0.562-0.799). To improve diagnostic effectiveness, the Rad-score created a novel prediction nomogram by combining CA125 and CA72-4. The radiomics nomogram showed good calibration and discrimination in the training set (AUC, 0.900; 95% CI, 0.844-0.947) and the validation set (AUC, 0.838; 95% CI, 0.534-0.735). The radiomics nomogram proved to be clinically beneficial based on decision curve analysis. Conclusion: We developed and validated a radiomics nomogram model for predicting the response to platinum in SCLC patients. The outcomes of this model can provide useful suggestions for the development of tailored and customized second-line chemotherapy regimens.

4.
Mol Divers ; 2023 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-36949297

RESUMEN

Currently, recombinant tissue plasminogen activator (rtPA) is an effective therapy for ischemic stroke (IS). However, blood-brain barrier (BBB) disruption is a serious side effect of rtPA therapy and may lead to patients' death. The natural polyphenol apigenin has a good therapeutic effect on IS. Apigenin has potential BBB protection, but the mechanism by which it protects the BBB integrity is not clear. In this study, we used network pharmacology, bioinformatics, molecular docking and molecular dynamics simulation to reveal the mechanisms by which apigenin protects the BBB. Among the 146 targets of apigenin for the treatment of IS, 20 proteins were identified as core targets (e.g., MMP-9, TLR4, STAT3). Apigenin protects BBB integrity by inhibiting the activity of MMPs through anti-inflammation and anti-oxidative stress. These mechanisms included JAK/STAT, the toll-like receptor signaling pathway, and Nitrogen metabolism signaling pathways. The findings of this study contribute to a more comprehensive understanding of the mechanism of apigenin in the treatment of BBB disruption and provide ideas for the development of drugs to treat IS.

5.
Int J Biol Macromol ; 231: 123160, 2023 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-36610575

RESUMEN

Transarterial chemoembolization (TACE) is an important approach for the treatment of unresectable hepatocellular carcinoma (HCC). However, the lactic acid-induced acidic tumor microenvironment (TME) may reduce the therapeutic outcome of TACE. Herein, monodispersed gelatin microspheres loaded with calcium carbonate nanoparticles (CaNPs@Gel-MS) as novel embolic agents were prepared by a simplified microfluidic device. It was found that the particle size and homogeneity of as-prepared CaNPs@Gel-MS were strongly dependent on the flow rates of continuous and dispersed phases, and the inner diameter of syringe needle. The introduction of CaNPs provided the gelatin microspheres with an enhanced ability to encapsulate the chemotherapeutic drug of DOX, as well as a pH-responsive sustained drug release behavior. In vitro results revealed that CaNPs@Gel-MS could largely increase the cellular uptake and chemotoxicity of DOX by neutralizing the lactic acid in the culture medium. In addition, CaNPs@Gel-MS exhibited an excellent and persistent embolic efficiency in a rabbit renal model. Finally, we found that TACE treatment with DOX-loaded CaNPs@Gel-MS (DOX/CaNPs@Gel-MS) had a much stronger ability to inhibit tumor growth than the DOX-loaded gelatin microspheres without CaNPs (DOX@Gel-MS). Overall, CaNPs@Gel-MS could be a promising embolic microsphere that can significantly improve anti-HCC ability by reversing lactic acid-induced chemotherapy resistance during TACE treatment.


Asunto(s)
Carcinoma Hepatocelular , Quimioembolización Terapéutica , Neoplasias Hepáticas , Animales , Conejos , Carcinoma Hepatocelular/tratamiento farmacológico , Doxorrubicina , Neoplasias Hepáticas/tratamiento farmacológico , Microesferas , Gelatina , Ácido Láctico/uso terapéutico , Quimioembolización Terapéutica/métodos , Portadores de Fármacos/uso terapéutico , Microambiente Tumoral
6.
Biochim Biophys Acta Mol Basis Dis ; 1868(12): 166550, 2022 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-36150660

RESUMEN

The polarization of macrophages often leads to severe calcification and necrosis in aged atherosclerotic plaques, which eventually leads to poor prognosis of ischaemic cardiovascular and cerebrovascular diseases. More reliable diagnostic methods are urgently needed to discover therapeutic targets of macrophage polarization in aged atherosclerotic plaques. Metabolomics of aged plaques (n = 20) and macrophage polarization transcriptomes (n = 30) were integrated to identify metabolic therapeutic targets of macrophage polarization associated with aged plaque. Finally, metabolic inhibitors were used to verify the reliability of the target genes. Integrated multiomics analysis revealed that 6 metabolic pathways (including 21 genes) regulate macrophage polarization in aged atherosclerosis. Targeted treatment of macrophage polarization with metabolic inhibitors can effectively reduce the adverse risk of aged atherosclerosis. The combination of transcriptomics and metabolomics approaches can identify effective therapeutic targets for macrophage polarization in arteriosclerosis.


Asunto(s)
Aterosclerosis , Placa Aterosclerótica , Anciano , Aterosclerosis/tratamiento farmacológico , Aterosclerosis/genética , Aterosclerosis/metabolismo , Humanos , Macrófagos/metabolismo , Metabolómica , Placa Aterosclerótica/tratamiento farmacológico , Placa Aterosclerótica/genética , Placa Aterosclerótica/metabolismo , Reproducibilidad de los Resultados , Transcriptoma
7.
Int J Biol Sci ; 18(10): 4260-4274, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35844784

RESUMEN

Ferroptosis is a novel type of cell death characterized by iron-dependent lipid peroxidation that involves a variety of biological processes, such as iron metabolism, lipid metabolism, and oxidative stress. A growing body of research suggests that ferroptosis is associated with cancer and neurodegenerative diseases, such as glioblastoma, Alzheimer's disease, Parkinson's disease, and stroke. Building on these findings, we can selectively induce ferroptosis for the treatment of certain cancers, or we can treat neurodegenerative diseases by inhibiting ferroptosis. This review summarizes the relevant advances in ferroptosis, the regulatory mechanisms of ferroptosis, the participation of ferroptosis in brain tumors and neurodegenerative diseases, and the corresponding drug therapies to provide new potential targets for its treatment.


Asunto(s)
Ferroptosis , Neoplasias , Enfermedades Neurodegenerativas , Muerte Celular/fisiología , Humanos , Hierro/metabolismo , Peroxidación de Lípido , Neoplasias/metabolismo , Enfermedades Neurodegenerativas/tratamiento farmacológico
8.
Asian J Pharm Sci ; 17(6): 908-923, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36600896

RESUMEN

The development of novel theranostic agents with outstanding diagnostic and therapeutic performances is still strongly desired in the treatment of hepatocellular carcinoma (HCC). Here, a fucoidan-modified mesoporous polydopamine nanoparticle dual-loaded with gadolinium iron and doxorubicin (FMPDA/Gd3+/DOX) was prepared as an effective theranostic agent for magnetic resonance imaging (MRI)-guided chemo-photothermal therapy of HCC. It was found that FMPDA/Gd3+/DOX had a high photothermal conversion efficiency of 33.4% and excellent T1-MRI performance with a longitudinal relaxivity (r1) value of 14.966 mM-1·s - 1. Moreover, the results suggested that FMPDA/Gd3+/DOX could effectively accumulate into the tumor foci by dual-targeting the tumor-infiltrated platelets and HCC cells, which resulted from the specific interaction between fucoidan and overexpressed p-selectin receptors. The excellent tumor-homing ability and MRI-guided chemo-photothermal therapy therefore endowed FMPDA/Gd3+/DOX with a strongest ability to inhibit tumor growth than the respective single treatment modality. Overall, our study demonstrated that FMPDA/Gd3+/DOX could be applied as a potential nanoplatform for safe and effective cancer theranostics.

9.
J Environ Sci (China) ; 57: 221-230, 2017 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-28647242

RESUMEN

Engineered oxide nanoparticles (NPs) are widely applied in insulators, catalyzers, paints, cosmetic products, textiles and semiconductors. Their attachment on cell membrane may lead to cytotoxicity. The effects of Al2O3, Fe2O3, SiO2, TiO2 and ZnO NPs on membrane integrity and fluidity were studied using giant or small unilamellar vesicles in this study. Al2O3 and SiO2 NPs disrupted the oppositely charged membrane, indicating the important role of electrostatic attraction. However, Fe2O3, TiO2 and ZnO NPs did not cause serious membrane disruption as Al2O3 and SiO2 NPs. Membrane fluidity was evaluated by the generalized polarity (GP) values of Laurdan fluorescent emission. SiO2 NPs induce the membrane gelation of both positively and negatively charged membrane. Al2O3 and ZnO NPs induced the gelation of the oppositely charged membrane, but did not cause obvious membrane gelation to the like charged membrane. The phospholipid molecular structural changes after NP exposure were analyzed by Fourier transform infrared (FT-IR) spectroscopy. FT-IR spectra revealed the hydrogen bond formation between NPs and the carbonyl/phosphate groups of phospholipids. Al2O3 and SiO2 NPs showed strongest evidence of hydrogen bonding on their FT-IR spectra. It was consistent with the microscopic observation and fluorescent data that Al2O3 and SiO2 NPs caused more serious membrane disruption and gelation. This study on membrane damage provides further knowledge on the cytotoxicity of nanomaterials and the safety of NP application.


Asunto(s)
Nanopartículas del Metal/química , Modelos Químicos , Fosfolípidos/química , Enlace de Hidrógeno
10.
PLoS One ; 12(3): e0173645, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28362819

RESUMEN

Hyperbaric oxygen (HBO) therapy through breathing oxygen at the pressure of above 1 atmosphere absolute (ATA) is useful for varieties of clinical conditions, especially hypoxic-ischemic diseases. Because of generation of reactive oxygen species (ROS), breathing oxygen gas at high pressures can cause oxygen toxicity in the central nervous system, leading to multiple neurological dysfunction, which limits the use of HBO therapy. Studies have shown that Hydrogen gas (H2) can diminish oxidative stress and effectively reduce active ROS associated with diseases. However, the effect of H2 on ROS generated from HBO therapy remains unclear. In this study, we investigated the effect of H2 on ROS during HBO therapy using PC12 cells. PC12 cells cultured in medium were exposed to oxygen gas or mixed oxygen gas and H2 at 1 ATA or 5 ATA. Cells viability and oxidation products and ROS were determined. The data showed that H2 promoted the cell viability and inhibited the damage in the cell and mitochondria membrane, reduced the levels of lipid peroxidation and DNA oxidation, and selectively decreased the levels of •OH but not disturbing the levels of O2•-, H2O2, or NO• in PC12 cells during HBO therapy. These results indicated that H2 effectively reduced •OH, protected cells against oxygen toxicity resulting from HBO therapy, and had no effect on other ROS. Our data supported that H2 could be potentially used as an antioxidant during HBO therapy.


Asunto(s)
Hidrógeno/farmacología , Radical Hidroxilo/metabolismo , Oxígeno/toxicidad , Animales , Supervivencia Celular/efectos de los fármacos , L-Lactato Deshidrogenasa/metabolismo , Peroxidación de Lípido/efectos de los fármacos , Células PC12 , Ratas , Especies Reactivas de Oxígeno/metabolismo
11.
Environ Sci Technol ; 51(10): 5747-5755, 2017 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-28387520

RESUMEN

Emissions of perfluoroalkyl acids (PFAAs) have increased in China over the past decade, but human exposure pathways are poorly understood. Here we analyzed 15 PFAAs in commonly consumed food items and calculated body weight normalized dietary intake rates (estimated dietary intake, EDIs) in an area with ongoing PFAA production (Hubei province; n = 121) and an urbanized coastal area (Zhejiang province; n = 106). Geographical differences in concentrations were primarily observed for perfluorooctanesulfonic acid (PFOS) and perfluorohexanesulfonic acid (PFHxS) in animal food items and short-chain PFAAs in vegetable food items. The average EDI of ∑PFAAs for adults in Hubei (998 ng kg-1 day-1) was more than 2 orders of magnitude higher than that in Zhejiang (9.03 ng kg-1 day-1). In Hubei province, the average EDI of PFOS for adults (87 ng kg-1 day-1) was close to or exceeded advisory guidelines used in other countries indicating health risks for the population from long-term exposure. Yet, PFOS could only account for about 10% of the EDI of ∑PFAAs in the Hubei province, which was dominated by short-chain PFAAs through consumption of vegetables. The large contribution of short-chain PFAAs to the total EDIs in manufacturing areas emphasize the need for improved exposure and hazard assessment tools of these substances.


Asunto(s)
Ácidos Alcanesulfónicos/análisis , Dieta , Fluorocarburos/análisis , Contaminación de Alimentos , Adulto , Animales , Caprilatos , China , Femenino , Humanos , Masculino , Medición de Riesgo , Verduras
12.
Environ Sci Technol ; 50(21): 11584-11592, 2016 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-27689437

RESUMEN

An extensive sampling campaign was undertaken to study the levels, isomer profiles and riverine mass discharges of perfluoroalkyl acids (PFAAs) and fluorinated alternatives in 19 Chinese rivers. The levels and homologue profiles of Σ10PFAAs varied considerably among the 19 rivers (mean 106; median 16.3, range 8.9-1240 ng/L), indicating the influence of specific point sources. Highly branched isomer profiles of perfluorooctanoic acid (18-25% br-PFOA) in rivers with elevated concentrations (96-352 ng/L) indicate that releases during production of PFOA by electrochemical fluorination and/or its use in fluoropolymer manufacture were the dominant sources to these rivers. The fluorinated alternatives 6:2 fluorotelomer sulfonate (detection frequency 21%, < 0.1-3.1 ng/L) and chlorinated polyfluoroalkyl ether sulfonate F-53B (51%, < 0.56-78.5 ng/L) were also found in some rivers. The total Chinese riverine mass discharges of PFOA (mean 80.9; range 16.8-168 t/y) (including monitoring data from this and other studies) were in good agreement with theoretical PFOA emission estimates (17.3-203 t/y) whereas riverine mass discharges of PFOS (mean 3.6; range 1.9-5.6 t/y) could only account for a minor fraction of theoretically estimated PFOS releases (70 t/y). This study provides empirical evidence that emissions from Chinese point sources likely dominate the global emissions of several legacy PFASs (notably PFOA) and fluorinated alternatives (e.g., F-53B).


Asunto(s)
Monitoreo del Ambiente , Ríos , Isomerismo , Contaminantes Químicos del Agua
13.
Org Lett ; 18(14): 3322-5, 2016 07 15.
Artículo en Inglés | MEDLINE | ID: mdl-27366912

RESUMEN

An unusual cascade reaction featuring annulation of diarylalkyne sulfonamides to form 5,10-dihydroindolo[3,2-b]indoles has been realized with Cu(OAc)2 as the sole oxidant. This unprecedented process encompasses two sequential C-N bond formations, allowing for an efficient synthesis of the biologically important indoloindole derivatives.

14.
Environ Sci Pollut Res Int ; 23(16): 16440-7, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-27164882

RESUMEN

The distribution and fate of polybrominated diphenyl ethers (PBDEs) in a riparian ecosystem nearby a wastewater treatment plant effluent were investigated. Different aqueous and terrestrial samples such as soil, sediment, plants, and invertebrates were collected and analyzed for tri- to heptabrominated PBDEs. Furthermore, the food web structure was elucidated using stable carbon and nitrogen isotopes. The highest PBDE levels were found for sediment- and soil-dwelling invertebrates, such as earthworms (Σ13 PBDEs 144 ng/g lipid weight), Tubifex tubifex (77 ng/g lw), and scarab larvae (49 ng/g lw). Differences in congener composition profiles among the different matrices show that the environmental distribution and fate of PBDEs in ecosystems can be very complex. Among the analyzed PBDEs in this ecosystem, the tetra-brominated BDE-47 was the dominant PBDE congener and followed by the penta-brominated BDE-99. A potential trend of increasing BDE-47/99 ratio with the increase of δ(15)N was observed for species with similar energy sources (δ(13)C), indicating a higher bioaccumulation potential for BDE-47 in this ecosystem. A significant correlation was also found between PBDEs and polychlorinated biphenyls (PCBs), indicating similar sources and fate between the two compound groups in this area. The biota-soil or biota-sediment accumulation factors (BSAFs) were somewhat different among the PBDE congeners and species, but were generally highest for those with log Kow values around 6.5-7.


Asunto(s)
Monitoreo del Ambiente , Contaminantes Ambientales/análisis , Éteres Difenilos Halogenados/análisis , Instalaciones de Eliminación de Residuos , Eliminación de Residuos Líquidos , Aguas Residuales/química , Animales , Ecosistema , Cadena Alimentaria , Isótopos de Nitrógeno/análisis , Oligoquetos , Bifenilos Polibrominados/análisis , Bifenilos Policlorados/análisis , Suelo/química , Contaminantes del Suelo/análisis
15.
J Hazard Mater ; 287: 217-24, 2015 Apr 28.
Artículo en Inglés | MEDLINE | ID: mdl-25661168

RESUMEN

Silicon nanoparticles (NPs) are widely used nanomaterials and reported to have pathogenicity. Effects of five different SiO2 NPs on the membrane integrity and fluidity were studied using giant unilamellar vesicles (GUVs) as model cell membranes. GUVs were made from 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) by gentle hydration method, and adjusted to be positively- or negatively-charged by adding charged lipids into vesicles. SiO2 NPs caused more serious damage to oppositely-charged membrane because electrostatic attraction favored the hydrogen bonding to the phospholipids. Increase in NP exposure dose/time and NP sedimentation process aggravated the membrane damage. The membrane phases were evaluated applying the fluorescent probe Laurdan and the calculated generalized polarization (GP) values. Anionic SiO2 NPs increased the GP value and induced membrane gelation. Cationic SiO2 NPs did not change the phase of positively-charged GUV and pure DOPC vesicles, but induced the gelation of negatively-charged GUV. Break of membrane integrity and change in membrane phase are possible mechanisms of cytotoxicity because cellular physiological activities require a separated intracellular environment and a fluid membrane phase to support proteins and regulate molecular transport.


Asunto(s)
Nanopartículas/química , Fosfatidilcolinas/química , Dióxido de Silicio/química , Liposomas Unilamelares , Coloides , Porosidad , Polvos
16.
Environ Pollut ; 196: 309-12, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25463727

RESUMEN

Short chain chlorinated paraffins (SCCPs) have been of considerable concern in recent years due to their high production volumes, environmental persistency and potential for long range atmospheric transport. Vegetation can take up considerable amounts of semivolatile organic compounds from the atmosphere and can act as indicators of local contamination. Paired pine needles and bark were sampled around Beijing during winter and summertime to investigate the distribution of SCCPs in urban areas. Levels in bark samples ranged 5.79-37.5 µg/g on a lipid normalized basis (lw) with a geometric mean (GM) of 16.9 µg/g lw whereas levels were 3.03-40.8 (GM 11.8) µ/g lw for needles. Average congener group abundance profiles showed equal contribution of all four carbon groups (C(10-13)) in wintertime where as higher abundances of C(10) and C(11) groups were found during summer. Uptake of SCCPs occurred mainly via kinetically limited gaseous deposition and particle bound deposition in the investigated area.


Asunto(s)
Contaminantes Atmosféricos/análisis , Monitoreo del Ambiente , Parafina/análisis , Corteza de la Planta/química , Hojas de la Planta/química , Aire , Atmósfera/química , Carbono , Ciudades , Hidrocarburos Clorados/análisis , Estaciones del Año
17.
Huan Jing Ke Xue ; 35(5): 1955-61, 2014 May.
Artículo en Chino | MEDLINE | ID: mdl-25055692

RESUMEN

Seafood samples were collected from Dalian, China to study the accumulation and distribution characteristics of short chain chlorinated paraffins (SCCPs) by GC/ECNI-LRMS. Sum of SCCPs (dry weight) were in the range of 77-8 250 ng.g-1, with the lowest value in Scapharca subcrenata and highest concentration in Neptunea cumingi. The concentrations of sum of SCCPs (dry weight) in fish, shrimp/crab and shellfish were in the ranges of 100-3 510, 394-5 440, and 77-8 250 ng.g-1 , respectively. Overall, the C10 and C11 homologues were the most predominant carbon groups of SCCPs in seafood from this area,and a relatively higher proportion of C12-13 was observed in seafood with higher concentrations of sum of SCCPs . With regard to chlorine content, Cl1,, CI8 and CI6 were the major groups. Significant correlations were found among concentrations of different SCCP homologues (except C1, vs. Cl10 ) , which indicated that they might share the same sources and/or have similar accumulation, migration and transformation processes.


Asunto(s)
Monitoreo del Ambiente , Hidrocarburos Clorados/análisis , Parafina/análisis , Alimentos Marinos/análisis , Animales , China , Peces , Contaminación de Alimentos/análisis , Moluscos
18.
Sci Total Environ ; 463-464: 252-7, 2013 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-23811358

RESUMEN

In this study, we investigated the distribution of polychlorinated biphenyls (PCBs) in a riparian zone affected by the effluent from a wastewater treatment plant (WWTP). River water, sediment, aquatic invertebrates and samples from the surrounding terrestrial compartment such as soil, reed plants and several land based invertebrates were collected. A relatively narrow range of δ(13)C values was found among most invertebrates (except butterflies, grasshoppers), indicating a similar energy source. The highest concentration of total PCBs was observed in zooplankton (151.1 ng/g lipid weight), and soil dwelling invertebrates showed higher concentrations than phytophagous insects at the riparian zone. The endobenthic oligochaete Tubifex tubifex (54.28 ng/g lw) might be a useful bioindicator of WWTP derived PCBs contamination. High bioaccumulation factors (BAFs) were observed in collected aquatic invertebrates, although the biota-sediment/soil accumulation factors (BSAF) remained relatively low. Emerging aquatic insects such as chironomids could carry waterborne PCBs to the terrestrial compartment via their lifecycles. The estimated annual flux of PCBs for chironomids ranged from 0.66 to 265 ng⋅m(-2)⋅y(-1). Although a high prevalence of PCB-11 and PCB-28 was found for most aquatic based samples in this riparian zone, the mid-chlorinated congeners (e.g. PCB-153 and PCB-138) became predominant among chironomids and dragonflies as well as soil dwelling invertebrates, which might suggest a selective biodriven transfer of different PCB congeners.


Asunto(s)
Invertebrados/metabolismo , Bifenilos Policlorados/análisis , Ríos/química , Suelo/química , Aguas Residuales/química , Contaminantes Químicos del Agua/análisis , Animales , Isótopos de Carbono/análisis , Chironomidae/metabolismo , Insectos/metabolismo , Isótopos de Nitrógeno/análisis
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