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1.
Environ Health ; 23(1): 38, 2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38609943

RESUMO

BACKGROUND: Per- and polyfluoroalkyl substances (PFAS) are known environmental contaminants with immunosuppressive properties. Their connection to rheumatoid arthritis (RA), a condition influenced by the immune system, is not well studied. This research explores the association between PFAS exposure and RA prevalence. METHODS: This research utilized data from the NHANES, encompassing a sample of 10,496 adults from the 2003-2018 cycles, focusing on serum levels of several PFAS. The presence of RA was determined based on self-reports. This study used multivariable logistic regression to assess the relationship between individual PFAS and RA risk, adjusting for covariates to calculate odds ratios (ORs). The combined effects of PFAS mixtures were evaluated using BKMR, WQS regression, and quantile g-computation. Additionally, sex-specific associations were explored through stratified analysis. RESULTS: Higher serum PFOA (OR = 0.88, 95% CI: 0.79, 0.98), PFHxS (OR = 0.91, 95% CI: 0.83, 1.00), PFNA (OR = 0.87, 95% CI: 0.77, 0.98), and PFDA (OR = 0.89, 95% CI: 0.81, 0.99) concentration was related to lower odds of RA. Sex-specific analysis in single chemical models indicated the significant inverse associations were only evident in females. BKMR did not show an obvious pattern of RA estimates across PFAS mixture. The outcomes of sex-stratified quantile g-computation demonstrated that an increase in PFAS mixture was associated with a decreased odds of RA in females (OR: 0.76, 95% CI: 0.62, 0.92). We identified a significant interaction term of the WQS*sex in the 100 repeated hold out WQS analysis. Notably, a higher concentration of the PFAS mixture was significantly associated with reduced odds of RA in females (mean OR = 0.93, 95% CI: 0.88, 0.98). CONCLUSIONS: This study indicates potential sex-specific associations of exposure to various individual PFAS and their mixtures with RA. Notably, the observed inverse relationships were statistically significant in females but not in males. These findings contribute to the growing body of evidence indicating that PFAS may have immunosuppressive effects.


Assuntos
Artrite Reumatoide , Fluorocarbonos , Adulto , Feminino , Masculino , Humanos , Inquéritos Nutricionais , Artrite Reumatoide/induzido quimicamente , Artrite Reumatoide/epidemiologia , Razão de Chances , Autorrelato
2.
Bioorg Chem ; 145: 107216, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38387396

RESUMO

ß-Carboline alkaloids are natural and synthetic products with outstanding antitumor activity. C3 substituted and dimerized ß-carbolines exert excellent antitumor activity. In the present research, 37 ß-carboline derivatives were synthesized and characterized. Their cytotoxicity, cell cycle, apoptosis, and CDK2- and DNA-binding affinity were evaluated. ß-Carboline monomer M3 and dimer D4 showed selective activity and higher cytotoxicity in tumor cells than in normal cells. Structure-activity relationships (SAR) indicated that the amide group at C3 enhanced the antitumor activity. M3 blocked the A549 (IC50 = 1.44 ± 1.10 µM) cell cycle in the S phase and inhibited A549 cell migration, while D4 blocked the HepG2 (IC50 = 2.84 ± 0.73 µM) cell cycle in the G0/G1 phase, both of which ultimately induced apoptosis. Furthermore, associations of M3 and D4 with CDK2 and DNA were proven by network pharmacology analysis, molecular docking, and western blotting. The expression level of CDK2 was downregulated in M3-treated A549 cells and D4-treated HepG2 cells. Moreover, M3 and D4 interact with DNA and CDK2 at sub-micromolar concentrations in endothermic interactions caused by entropy-driven adsorption processes, which means that the favorable entropy change (ΔS > 0) overcomes the unfavorable enthalpy change (ΔH > 0) and drives the spontaneous reaction (ΔG < 0). Overall, these results clarified the antitumor mechanisms of M3 and D4 through disrupting the cell cycle by binding DNA and CDK2, which demonstrated the potential of M3 and D4 as novel antiproliferative drugs targeting mitosis.


Assuntos
Antineoplásicos , Proliferação de Células , Simulação de Acoplamento Molecular , Ciclo Celular , Relação Estrutura-Atividade , Antineoplásicos/farmacologia , Antineoplásicos/química , DNA , Carbolinas/farmacologia , Carbolinas/química , Linhagem Celular Tumoral , Ensaios de Seleção de Medicamentos Antitumorais , Estrutura Molecular
3.
New Phytol ; 242(2): 558-575, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38396374

RESUMO

Black wolfberry (Lycium ruthenicum Murr.) contains various bioactive metabolites represented by flavonoids, which are quite different among production regions. However, the underlying regulation mechanism of flavonoid biosynthesis governing the bioactivity of black wolfberry remains unclear. Presently, we compared the bioactivity of black wolfberry from five production regions. Multi-omics were performed to construct the regulation network associated with the fruit bioactivity. The detailed regulation mechanisms were identified using genetic and molecular methods. Typically, Qinghai (QH) fruit exhibited higher antioxidant and anti-inflammatory activities. The higher medicinal activity of QH fruit was closely associated with the accumulation of eight flavonoids, especially Kaempferol-3-O-rutinoside (K3R) and Quercetin-3-O-rutinoside (rutin). Flavonoid biosynthesis was found to be more active in QH fruit, and the upregulation of LrFLS, LrCHS, LrF3H and LrCYP75B1 caused the accumulation of K3R and rutin, leading to high medicinal bioactivities of black wolfberry. Importantly, transcription factor LrMYB94 was found to regulate LrFLS, LrCHS and LrF3H, while LrWRKY32 directly triggered LrCYP75B1 expression. Moreover, LrMYB94 interacted with LrWRKY32 to promote LrWRKY32-regulated LrCYP75B1 expression and rutin synthesis in black wolfberry. Transgenic black wolfberry overexpressing LrMYB94/LrWRKY32 contained higher levels of K3R and rutin, and exhibited high medicinal bioactivities. Importantly, the LrMYB94/LrWRKY32-regulated flavonoid biosynthesis was light-responsive, showing the importance of light intensity for the medicinal quality of black wolfberry. Overall, our results elucidated the regulation mechanisms of K3R and rutin synthesis, providing the basis for the genetic breeding of high-quality black wolfberry.


Assuntos
Lycium , Lycium/genética , Melhoramento Vegetal , Flavonoides , Antioxidantes , Rutina , Frutas/genética
4.
Plant Physiol ; 192(2): 1396-1419, 2023 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-36943289

RESUMO

Cytospora canker, caused by Cytospora mali, is the most destructive disease in production of apples (Malus domestica). Adding potassium (K) to apple trees can effectively control this disease. However, the underlying mechanisms of apple resistance to C. mali under high-K (HK) status remain unknown. Here, we found that HK (9.30 g/kg) apple tissues exhibited high disease resistance. The resistance was impeded when blocking K channels, leading to susceptibility even under HK conditions. We detected a suite of resistance events in HK apple tissues, including upregulation of resistance genes, callose deposition, and formation of ligno-suberized tissues. Further multiomics revealed that the phenylpropanoid pathway was reprogrammed by increasing K content from low-K (LK, 4.30 g/kg) status, leading to increases of 18 antifungal chemicals. Among them, the physiological concentration of coumarin (1,2-benzopyrone) became sufficient to inhibit C. mali growth in HK tissues, and exogenous application could improve the C. mali resistance of LK apple branches. Transgenic apple calli overexpressing beta-glucosidase 40 (MdBGLU40), which encodes the enzyme for coumarin synthesis, contained higher levels of coumarin and exhibited high resistance to C. mali even under LK conditions. Conversely, the suppression of MdBGLU40 through RNAi reduced coumarin content and resistance in HK apple calli, supporting the importance of coumarin accumulation in vivo for apple resistance. Moreover, we found that the upregulation of transcription factor MdMYB1r1 directly activated MdBGLU40 and the binding affinity of MdMYB1r1 to the MdBGLU40 promoter increased in HK apple tissue, leading to high levels of coumarin and resistance in HK apple. Overall, we found that the accumulation of defensive metabolites strengthened resistance in apple when raising K from insufficient to optimal status, and these results highlight the optimization of K content in fertilization practices as a disease management strategy.


Assuntos
Ascomicetos , Malus , Malus/metabolismo , Ascomicetos/genética , Potássio/metabolismo , Cumarínicos/metabolismo
5.
Front Immunol ; 13: 922183, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36325324

RESUMO

ß-Carbolines are potentially strong alkaloids with a wide range of bioactivities, and their dimers exhibit stronger antitumor activity other than the monomers. However, the detailed mechanisms of the ß-carboline dimers in inhibiting sarcoma (SARC) remain unclear. The results showed that ß-carboline-3-carboxylic acid dimers Comp1 and Comp2, which were synthesized in our lab and modified at the N9 position and linked at the C3 position, exhibited effective inhibition activity on MG-63 proliferation (IC50 = 4.6µM). Meanwhile, the large scale transcriptome profiles of SARC from The Cancer Genome Atlas (TCGA) were analyzed, and found that abnormal expression of genes relevant to apoptosis, cell cycle, and signaling pathways of Hedgehog, HIF, Ras involved in the SARC pathogenesis. Interestingly, both dimers could promote the apoptosis and arrest the cell cycle in S phase to inhibit proliferation of MG-63. Moreover, Comp1 and Comp2 inhibited the expression CDK2, CCNA2, DBF4, and PLK1 associated with various immune cells and cell cycle in MG-63. Remarkably, drug-target interaction network analysis showed that numerous proteins involved in cell cycle were the potential targets of Comp1 and Comp2, especially CCNA2. Further molecular docking, isothermal titration calorimetry (ITC) and Cellular Thermal Shift Assay (CETSA) confirmed that both dimers could directly interact with CCNA2, which is significantly correlated with CD4+ T cells, by strong hydrophobic interactions (Kd=5.821 ×106 N). Meanwhile, the levels of CCNA2 and CDK2 were inhibited to decrease in MG-63 by both dimer treatments at transcription and protein levels, implying that Comp1 and Comp2 blocked the interaction between CCNA2 and CDK2 through competitive binding with CCNA2 to arrest the cell cycle of MG-63 cells in the S phase. Additionally, the transcriptome profiles of ß-carboline-treated mice from Gene Expression Omnibus (GEO) were obtained, and found that similar antitumor mechanism was shared among ß-carboline derivatives. Overall, our results elucidated the antitumor mechanisms of Comp1 and Comp2 through dual-suppressing the function of CCNA2 to profoundly arrest cell cycle of MG-63, then effectively inhibited cell proliferation of MG-63. These results provide new insights into the antitumor mechanism of ß-carboline dimers and new routes of various novel cancer-related drug targets for future possible cancer therapy.


Assuntos
Antineoplásicos , Sarcoma , Animais , Camundongos , Simulação de Acoplamento Molecular , Linhagem Celular Tumoral , Carbolinas/farmacologia , Carbolinas/química , Pontos de Checagem do Ciclo Celular , Proliferação de Células , Antineoplásicos/farmacologia , Antineoplásicos/química
6.
Sci Rep ; 12(1): 13115, 2022 07 30.
Artigo em Inglês | MEDLINE | ID: mdl-35908111

RESUMO

The lipid composition performs important functions in interaction between macropha-ge and Mycobacterium tuberculosis (MTB)/Mycobacterium bovis (MB). Current understanding regarding the lipid responses of bovine alveolar macrophage (BAM) to MTB/MB is quite limited. The present study conducted lipidomics and transcriptome to assess alterations in BAM lipid compositions upon MB and MTB infection. We found that both MTB and MB induced glycerophospholipids accumulation in BAM, and MTB induced more alterations in lipid composition. MTB could affect the contents of various lipids, especially ceramide phosphocholines, polystyrene (PS) (17:0/0:0), testolic acid and testosterone acetate. Meanwhile, MB particularly induced accumulation of 1-alkyl,2-acylglycerophosphoinositols. Both MB and MTB suppressed the contents of palmitoleamide, N-ethyl arachidonoyl amine, N-(1,1-dimethyl-2-hydroxy-ethyl) arachidonoyll amine, eicosanoyl-EA, and PS (O-18:0/17:0) in BAM. Additionally, transcriptome analysis revealed that only MTB triggered genes involved in immune signaling and lipid related pathways in BAM. And MTB mainly activated genes CXCL2 and CXCL3 relevant to NOD-like receptor, IL-17 and TNF to further induce lipid accumulation in BAM, which in turn promoted the formation of foam cells. Meanwhile, time course RT-qPCR results showed that MTB was recognized by BAM to triggered dramatic immune responses, whereas MB could effectively escape the recognition system of BAM, leading rearrangement of lipid metabolisms in BAM at early infection stage. Altogether, the results of the present study provided evidence for changes in lipid metabolism of MTB/MB attacked BAM and contributed to the detection and treatment of zoonotic tuberculosis.


Assuntos
Mycobacterium bovis , Mycobacterium tuberculosis , Tuberculose dos Linfonodos , Aminas/farmacologia , Animais , Bovinos , Lipídeos/farmacologia , Macrófagos Alveolares
7.
PeerJ ; 9: e12585, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34917427

RESUMO

BACKGROUND: Gouty arthritis (GA) is a common type of inflammatory arthritis. Recent studies demonstrated that 1,25-dihydroxy vitamin D3 (1,25(OH) 2 VD3) and vitamin D3 receptor (VD-R) play a protective role in acute inflammation, but interleukin-22(IL-22) promotes inflammation, especially for arthritis. However, our understanding of the responses of 1,25(OH) 2VD3 and IL-22 to gout was still unclear. Presently, in-depth metabolomics, bioinformatics and clinical characteristics analyses were performed to elucidate the pathogenesis and valuable clinical indicators of gouty arthritis. METHODS: Peripheral venous blood was taken for investigation. The levels of IL-22 and 1,25(OH)2VD3 were determined in patient's plasma via ELISA, and the mRNA levels of IL-22 and VD-R were measured via qRT-PCR. The interaction network of VD-R and IL22 were constructed by the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING), and the biological function of the related proteins were analyzed by Clusterprofiler Metabolomics were performed to decipher the metabolic variations of GA. RESULTS: The levels of VD-R and 1,25(OH) 2 VD3 were identified to be low. What,s more, GA patients were reported to have high expression of IL-22. And IL-22 levels positively correlated with C-reactiveprotein (CRP) serum levels in the bivariate correlation analysis, whereas the level of 1,25(OH) 2VD3 negatively correlated with that of CRP. GO and KEGG analyses revealed that IL-22 and 1,25(OH) 2 VD3 were involved in stress immunity and inflammatory responses. These pathways are known to play a role in GA pathogenesis. Meanwhile, the metabolic profiles of GA serum showed that the increase in various amino acids and uric acid are involved in GA pathogenesis. Importantly, VD-R and IL22 closely correlated with the level of key metabolites uric acid, whose increase promoted the occurrence of GA. CONCLUSION: GA patients have low levels of VD-R and 1,25(OH) 2 VD3, and high levels of IL-22 together with various amino acids and uric acid. The levels of IL-22 and 1,25(OH) 2VD3 were positively and negatively correlated with C-reactive protein (CRP) serum levels, respectively. Both IL-22 and 1,25(OH) 2 VD3 functioned in GA-related immune and inflammatory responses, and closely correlated with the level of GA-related uric acid. Overall, IL-22, VD-R and 1,25(OH) 2 VD3 play functionally important roles in inflammatory responses and are relevant to gout pathogenesis.

8.
Int J Clin Pract ; : e13438, 2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31633263

RESUMO

AIMS: Several studies have reported a potential association between prostate volume (PV) and prostate disease. Here, we classified the risk factors for PV among benign prostatic hyperplasia (BPH) patients. METHODS: In all, 4293 BPH patients with available clinical information were enrolled. Body mass index (BMI) was obtained as weight divided by height squared. PV was calculated as length × width × height (cm) × π/6. Mann-Whitney U tests were used to determine the differences between PV subgroups. Univariate and multiple linear regression tests were performed to uncover the connection between clinical features and PV. The differences in the age, BMI, height and fasting blood glucose (FBG) of the subgroups were evaluated by Kruskal-Wallis tests and adjusted with Bonferroni post hoc correction. A nomogram was created to directly illustrate the mutual interaction of amalgamator parameters. RESULTS: PV did not influence the incidence of kidney stones (P = .815), whereas prostate calculi were positively associated with an enlarged prostate (>30 mL) (P < .001). Age (adjusted R = 0.363, P < .001), height (adjusted R = 0.088, P < .001), BMI (adjusted R = 0.039, P = .013) and FBG (adjusted R = -0.034, P = .027) were the independent risk/protective factors related to enlarged PV among BPH patients. The nomogram illustrated the predictive risk of an enlarged prostate (>30 mL) in men. The area under the ROC curve value was 0.659 in the training cohort and 0.677 in an internal validation cohort. CONCLUSIONS: Age, height and BMI were positive independent risk factors of enlarged PV in BPH patients, and FBG had a protective role.

9.
Artif Organs ; 42(12): 1185-1195, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30044004

RESUMO

The factors affecting hemoglobin (Hb) oxidation in its short- and long-term storage were investigated. Porcine Hb with different levels of oxygen saturation was stored at 25°C or 4°C for 40 days. The methemoglobin (metHb) content increased rapidly when Hb was at half saturation with oxygen at 4°C, increased gradually with the increase in Hb oxygenation or deoxygenation, and was almost unchanged when Hb was highly oxygenated or deoxygenated. The Hb oxidation was more intense when stored at 25°C. This indicated that highly oxygenated or deoxygenated Hb can be stored short term at 4°C. The accelerated test showed that metHb content was almost unchanged when Hb was highly deoxygenated and stored at 37°C for 7 days; however, the metHb content rapidly increased when Hb was highly oxygenated and stored at 37°C, which indicated that only highly deoxygenated Hb is suitable for long-term storage. Then, the long-term oxidation stability of highly deoxygenated Hb and polymerized hemoglobin was verified; the metHb content of both did not show significant changes at 4°C for 18 months. Moreover, the results in this work indicated that a temperature increasing from 20 to 40°C clearly increased the partial oxygen pressure (P50), which represents decreased oxygen affinity and is beneficial to deoxygenation. Furthermore, P50 was increased when the pH decreased from 9 to 7. Therefore, we concluded that the appropriate high temperature and neutral condition in vitro are conducive to reducing the oxygen affinity of Hb to achieve efficient deoxygenation, which could promote the development of hemoglobin-based oxygen carriers.


Assuntos
Hemoglobinas/química , Armazenamento de Medicamentos , Oxirredução
10.
J Chromatogr Sci ; 56(7): 636-643, 2018 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-29701750

RESUMO

A rapid and simple high-performance liquid chromatography-ultraviolet method was developed for the separation and quantification of 15 sulfonamides (SAs) in foods of animal origin without the need of clean-up procedure. A mixture of acetonitrile-formic acid-ammonium acetate-water was used as the mobile phase to separate 15 SAs on a C18 column with gradient. The selected SAs were separated completely from the matrix mixture based on different retention behaviors at different concentration of acetonitrile. The effects of the additive of formic acid and ammonium acetate in mobile phases on the separation of SAs were also investigated. The additive can greatly improve the resolution between SAs and impurities, so that the SAs can be quantified directly under the optimized chromatographic condition the sample preparation which does not need extra sample clean-up procedure. Complete baseline separation of 15 SAs was achieved in <40 min, the linear range is 0.01-130 µg/mL with a correlation coefficient R2-value > 0.999. Excellent method reproducibility was found by intra- and inter-day precisions with the relative standard deviation <9.5%. The detection limit was <11.0 ng/mL and it can be used for routine screening of the SA residues in foods of animal origin.


Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Resíduos de Drogas/análise , Carne/análise , Sulfonamidas/análise , Animais , Bovinos , Limite de Detecção , Modelos Lineares , Leite/química , Reprodutibilidade dos Testes , Espectrofotometria Ultravioleta , Suínos
11.
Artif Cells Nanomed Biotechnol ; 46(1): 47-55, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28521553

RESUMO

A Tempol compound with an amine group (4-amino-2,2,6,6-tetramethylpiperidine-1-oxyl, NH2-Tempol) was cross-linked to hemoglobin in a one-step polymerization reaction to produce a novel hemoglobin-based oxygen carrier (HBOC) designated PolyHb-Tempol. The reaction parameters, including the reaction time, pH, temperature, and ratio of reactants, were optimized, and the physiochemical properties of the resulting product were characterized. PolyHb-Tempol didn't show any toxicity towards endothelial cells. Furthermore, from observations of cell morphology and viability, PolyHb-Tempol showed a significant ability to inhibit or eliminate oxidative stress induced by superoxide free radicals. These results suggest that PolyHb-Tempol may potentially be suitable as an HBOC.


Assuntos
Óxidos N-Cíclicos/química , Células Endoteliais/efeitos dos fármacos , Glutaral/química , Hemoglobinas/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Superóxido Dismutase/metabolismo , Superóxidos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Hemoglobinas/química , Concentração de Íons de Hidrogênio , Cinética , Polimerização , Marcadores de Spin , Temperatura
12.
Artif Cells Nanomed Biotechnol ; 46(1): 33-38, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29081252

RESUMO

Glutaraldehyde (GA), used medically as a disinfectant and as a crosslinker for haemoglobin (Hb)-based oxygen carriers (HBOCs), was investigated for its ability to inactivate viruses during the preparation of these artificial blood substitutes. Porcine parvovirus (PPV; a non-enveloped DNA virus) and porcine pseudorabies virus (PRV; an enveloped DNA virus) were used as the virus indicators. Upon treatment with 0.1 mM GA, the titer of PRV decreased from 9.62 log10 to 2.62 log10 within 0.5 h, whereas that of PPV decreased from 7.00 log10 to 2.30 log10 in 5 h. Following treatment with 1.0 mM GA, the titer of PRV decreased from 11.00 log10 to 1.97 log10 within 0.5 h, whereas that of PPV decreased from 7.50 log10 to 3.43 log10 in 4.5 h. During the polymerization of Hb with GA, the GA concentration decreased to 1.0 and 0.1 mM within 30 and 50 min, respectively, at a GA:Hb molar ratio of 10:1, whereas at a GA:Hb molar ratio of 30:1, GA decreased to those same concentrations in 1.5 and 2.5 h, respectively. This rapid decrease in GA concentration during its polymerization with Hb indicates that GA must be added into the Hb solution in a short time in order to get as high a initial concentration as possible. In this study, the GA can only inactivate PRV effectively, given that a longer time (4.5 h) was required for it to inactivate the PPV titer. This study therefore demonstrates that GA inactivates the enveloped DNA virus only during the preparation of HBOCs.


Assuntos
Glutaral/farmacologia , Hemoglobinas/metabolismo , Herpesvirus Suídeo 1/efeitos dos fármacos , Oxigênio/metabolismo , Parvovirus Suíno/efeitos dos fármacos , Inativação de Vírus/efeitos dos fármacos , Animais , Linhagem Celular , Herpesvirus Suídeo 1/fisiologia , Parvovirus Suíno/fisiologia , Polimerização , Segurança
13.
Huan Jing Ke Xue ; 37(5): 1692-8, 2016 May 15.
Artigo em Chinês | MEDLINE | ID: mdl-27506021

RESUMO

In order to quantitatively identify sources of nitrate pollution in Beijing urban area and provide effective guidance for relevant departments to control the pollution of Beijing rivers, δ¹5N-NO3⁻ and δ¹8O-NO3⁻ isotope tracing method was used to analyze the composition of nitrogen and oxygen stable isotopes from nitrate in Beijing urban river. Besides, stable isotope mixing model was adopted to track nitrogen sources of nitrate in Beijing urban rivers and the contribution rates of respective pollution sources were evaluated. The results showed that: (1) NO3⁻-N pollution was the main inorganic nitrogen pollution in Beijing rivers and pollution of downstream was more serious than that of upstream. (2) δ¹5N-NO3⁻ in Beijing urban surface rivers was in range of 6.26 per thousand-24.94 per thousand, while δ¹8O-NO3⁻ ranged -0.41 per thousand-11.74 per thousand; δ¹5N-NO3⁻ increased from upstream to downstream along the flow of the surface water. (3) The nitrate pollution composition of Beijing rivers could be gained from the stable isotope mixing model. The average contribution rates of manure and sewage, soil nitrate and atmospheric deposition were 61.2%, 31.5% and 7.3%, respectively.


Assuntos
Monitoramento Ambiental , Nitratos/análise , Isótopos de Nitrogênio/análise , Isótopos de Oxigênio/análise , Rios/química , Poluentes Químicos da Água/análise , Pequim , Esterco , Modelos Teóricos , Esgotos , Solo
14.
Huan Jing Ke Xue ; 36(7): 2446-52, 2015 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-26489310

RESUMO

To understand the secondary river quality in Chongqing urban area, six typical secondary rivers were chosen to investigate the pollution characteristics of total nitrogen and total phosphorus and to evaluate the water eutrophication level according to the monitoring data of water physicochemical characteristics and chlorophyll content from April 2013 to March 2014. The study results showed that: the six rivers mentioned above have been seriously polluted by TN and TP, with the monthly mean values of TN and TP far exceeding the universally accepted threshold values of water eutrophication. Water eutrophicaton appraisal result indicated that all rivers in each season were in a state of eutrophication, and the eutrophication level could be arranged in the order of Panxi River > Qingshui River > Tiaodeng River > Huaxi River > Funiu River > Chaoyang River. The seasonal changes in TN and TP of secondary rivers were significant, with high concentrations of TN and TP in spring and winter, and lower concentrations in summer and autumn. TN and TP of the rivers showed a trend of increasing from the upstream to the downstream in each season. Pollutant concentration accumulated gradually along rivers and the maximum accumulation rate reached 1. 25 mg . (L . km) -1. Therefore, further study on urban secondary river pollution characteristics is of great significance to urban water pollution control.


Assuntos
Eutrofização , Nitrogênio/análise , Fósforo/análise , Rios/química , Poluentes Químicos da Água/análise , China , Clorofila , Cidades , Estações do Ano
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