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1.
Chem Biodivers ; 20(8): e202300793, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37485567

RESUMO

The utilization of rhizomes from the genus Atractylodes has been challenging due to their closely related origins. In this study, we developed an analytical strategy to differentiate Atractylodes lancea (A. lancea), Atractylodes chinensis (A. chinensis), Atractylodes japonica (A. japonica), and Atractylodes macrocephala (A. macrocephala), and compared their volatile compositions. Gas chromatography-mass spectrometry (GC/MS) was used to analyze the volatile profiles of essential oils extracted from 59 batches of samples. Chemometric methods enabled a better understanding of the differences in volatile oils between the four species and identified significant components affecting their classification and quality. A total of 50 volatile components were identified from the essential oils by GC/MS. Unsupervised and supervised chemometric analyses accurately distinguished A. lancea, A. chinensis, A. japonica, and A. macrocephala. Furthermore, five characteristic chemical markers, namely hinesol, ß-eudesmol, atractylon, atractylodin and atractylenolide I, were obtained, and their respective percentage contents in individual species and samples were determined. This study provides a valuable reference for the quality evaluation of medicinal plants with essential oils and holds significance for species differentiation and the rational clinical application of Atractylodes herbs.


Assuntos
Atractylodes , Óleos Voláteis , Plantas Medicinais , Cromatografia Gasosa-Espectrometria de Massas , Plantas Medicinais/química , Atractylodes/química , Quimiometria , Óleos Voláteis/química
2.
Environ Monit Assess ; 193(5): 244, 2021 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-33821354

RESUMO

Polybrominated diphenyl ethers (PBDEs) have been classified as persistent organic pollutants (POPs) as well as endocrine-disrupting compounds (EDCs). This study determined the concentrations of six PBDE congeners (BDE 47, BDE 99, BDE 100, BDE 153, BDE 154, and BDE 183) in water and sediment samples from open city drains, in the Makurdi Metropolitan Area, North Central Nigeria, using gas chromatogragh-mass spectrometer. These congeners are components of the penta- and octa-BDE formulations that have been banned by the European Union. The samples were collected from the drains, bi-monthly, for 1 year across dry and wet seasons. All the congeners considered were found to be present in both water and sediment. The levels of Σ6PBDEs in water ranged from 0.05 to 0.28 ng L-1 during dry season and 0.02 to 0.36 ng L-1 during wet season, while their levels in sediment during dry and wet seasons ranged from 3.22 to 26.26 ng g-1 and 7.51 to 27.41 ng g-1, respectively. The percentage recoveries from solid phase and Soxhlet extractions ranged from 69 to 104% and 70 to 112%, respectively. It was concluded that the presence of all the congeners in both water and sediment posed a pollution risk to the river in which the drains discharge and require further monitoring and necessary preventive measures.


Assuntos
Éteres Difenil Halogenados , Poluentes Químicos da Água , China , Cidades , Monitoramento Ambiental , Sedimentos Geológicos , Éteres Difenil Halogenados/análise , Nigéria , Água , Poluentes Químicos da Água/análise
3.
Artigo em Inglês | MEDLINE | ID: mdl-38982698

RESUMO

BACKGROUND: Hemerocallis citrina Baroni (Huanghuacai), a plant of the genus Hemerocallis in the family Asphodelaceae, is widely planted in China. Based on our survey results, the chemical compounds in the essential oil of the flowers of Hemerocallis citrina Baroni (EOFHCB) and relevant pharmacological activities have never been studied systematically. OBJECTIVE: To preliminarily decipher the pharmacological activities and mechanisms of EOFHCB in the treatment of anxiety disorders by GC-MS, Network Pharmacology, and Molecular docking. METHODS: EOFHCB compositions were identified using GC-MS, and their targets were predicted using Swiss Target Prediction databases. The targets of anxiety disorders were obtained by GeneCards, DisGeNET, and OMIM databases. The STRING database was used to construct the protein-protein interaction networks, and the DAVID database was used to carry out GO enrichment and KEGG pathway enrichment analysis. The EOFHCB-components-targetspathways- anxiety disorders network was constructed by Cytoscape software (Version 3.10.0). Finally, the result was verified by molecular docking. RESULTS: 28 chemical components were identified by GC-MS, including 3-furanmethanol (28.43%), 2-methyl-1-butanol (27.13%), nerolidol (10.62%), and so on, which correspond to 241 potential targets. Several 2440 biological processes, 187 cellular compositions, and 311 molecular functions were enriched by GO enrichment analysis and 174 pathways by KEGG enrichment analysis. The key targets are PTGS 2, SRC, DRD 2, ESR 1, MAOB, and SLC6A4. The most important pathway is the neuroactive ligand-receptor interaction. CONCLUSION: EOFHCB exerts its therapeutic effects on anxiety disorders through multicomponents, multi-targets, and multi-pathways, which provided new ideas and methods for the in-depth research of aromatic Chinese medicine in the treatment of anxiety disorders.

4.
Artigo em Inglês | MEDLINE | ID: mdl-36689564

RESUMO

The research goal was to estimate the level of risk to human health posed by polycyclic aromatic hydrocarbons (PAHs) in Vietnamese takeaway coffee. A variety of roasted coffee beans were collected and tested for the presence of PAHs in various takeaway locations throughout Vietnam. Furthermore, the effect of roasting conditions on PAH concentrations in Vietnamese Robusta coffee was also studied and demonstrated. Gas chromatography-mass spectrometry, a modern, accurate, and fast method, was used to determine the research results. Six PAHs, namely naphthalene, anthracene, pyrene, fluorene, phenanthrene, and benz[a]anthracene, were found in the 100 collected samples, with average concentrations (µg/kg dry weight) of 943.7 ± 40.3, 195.1 ± 4.9, 36.1 ± 1.1, 33.3 ± 2.2, 28.2 ± 1.7, and 2.0 ± 0.1, respectively. It was found that the tested samples were almost free of PAH4 contamination. The research showed that the total value of PAH quantifications in Robusta coffee increased with increasing roasting temperature and decreased with increasing roasting time. In addition, the calculated value of the total hazard quotient (THQ) was less than 1, and the obtained value of the incremental lifetime carcinogenic risk (ILCR) did not exceed 1·10-5, meaning that coffee consumers in Vietnam are safe from exposure to PAHs present in the investigated coffee beans.


Assuntos
Café , Hidrocarbonetos Policíclicos Aromáticos , Antracenos , Coffea , Hidrocarbonetos Policíclicos Aromáticos/análise , Temperatura , Vietnã , Café/química
5.
Environ Sci Pollut Res Int ; 30(30): 74877-74888, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37209329

RESUMO

Axial DC magnetic field-assisted multi-capillary underwater air bubble discharge plasma jet has been used to study the productions of reactive oxygen species. Analyses of optical emission data revealed that the rotational (Tr) and vibrational temperatures (Tv) of plasma species slightly increased with magnetic field strength. The electron temperature (Te) and density (ne) increased almost linearly with magnetic field strength. Te increased from 0.53 to 0.59 eV, whereas ne increased from 1.03 × 1015 cm-3 to 1.33 × 1015 cm-3 for B = 0 to B = 374 mT, respectively. Analytical results from the plasma treated water provided that the electrical conductivity (EC), oxidative reduction potential (ORP), and the concentrations of O3 and H2 O2 enhanced from 155 to 229 µS cm-1, 141 to 17 mV, 1.34 to 1.92 mg L-1, and 5.61 to 10.92 mg L-1 due to the influence of axial DC magnetic field, while [Formula: see text] reduced from 5.10 to 3.93 for 30 min treatment of water with B = 0 and B = 374 mT, respectively. The model wastewater prepared with Remazol brilliant blue textile dye and the plasma treated wastewater studied by optical absorption spectrometer, Fourier transform infrared spectrometer, and gas chromatography mass spectrometer. The results show that the decolorization efficiency increased ~ 20% after 5 min treatment for the maximum B = 374 mT with respect to zero-magnetic field and, power consumption, and electrical energy cost reduced ~ 6.3% and ~ 4.5%, respectively, due to the maximum assisted axial DC magnetic field strength of 374 mT.


Assuntos
Águas Residuárias , Água , Têxteis , Corantes/metabolismo , Indústria Têxtil
6.
Metabolites ; 12(6)2022 May 25.
Artigo em Inglês | MEDLINE | ID: mdl-35736412

RESUMO

Ellagic acid (EA) is a polyphenol dilactone that has been reported to have antipyretic, anti-inflammatory, anti-tumor, and antioxidant activities, but the mechanism of action has not been reported. In this study, serum metabolomics was used to explore the mechanism of EA on rat fever induced by beer yeast, and to screen out marker metabolites to provide a reference for the antipyretic effect of EA. The acute fever model of male Sprague Dawley rats involved subcutaneous injection with 20% aqueous suspension of yeast (15 mL/kg) in their back. At the same time of modeling, EA was given orally by 10 mL/kg intragastric administration for treatment. During the experiment, the temperature and its change values of rats were recorded, and Interleukin-6 (IL-6), Tumor Necrosis Factor-α (TNF-α), Prostaglandin E2 (PGE2), Cyclic Adenosine Monophosphate (cAMP), Superoxide Dismutase (SOD) and Malondialdehyde (MDA)­six physiological and biochemical indexes of rats­were detected after the experiment. In addition, the hypothalamus of each rat was analyzed by Western blot (WB), and the levels of Phospho Nuclear Factor kappa-B (P-NF-κB P65) and IkappaB-alpha (IKB-α) were detected. Then, the serum metabolites of rats in each group were detected and analyzed by gas chromatograph mass spectrometry and the multivariate statistical analysis method. Finally, when screening for differential metabolites, the potential target metabolic pathway of drug intervention was screened for through the enrichment analysis of differential metabolites. Pearson correlation analysis was used to systematically characterize the relationship between biomarkers and pharmacodynamic indicators. EA could reduce the temperature and its change value in yeast induced fever rats after 18 h (p < 0.05). The level of IL-6, TNF-α, PGE2, cAMP, SOD and MDA of the Model group (MG) increased significantly compared to the Normal group (NG) (p < 0.001) after EA treatment, while the levels of the six indexes in the serum and cerebrospinal fluid of yeast-induced rats decreased. The administration of yeast led to a significant increase in Hypothalamus P-NF-κB P65 and IKB-α levels. Treatment with EA led to a significant decrease in P-NF-κB P65 levels. Moreover, combined with VIP > 1 and p < 0.05 as screening criteria, the corresponding retention time and characteristic mass to charge ratio were compared with the NIST library, Match score > 80%, and a total of 15 differential metabolites were screened. EA administration significantly regulated 9 of 15 metabolites in rat serum. The 15 differential metabolites involved linoleic acid metabolism, phenylalanine, tyrosine and tryptophan biosynthesis, galactose metabolism, biosynthesis of unsaturated fatty acids and glycerolipid metabolism. Pharmacodynamic correlation analysis was conducted between 15 different metabolites and six detection indexes. There was a significant correlation between 13 metabolites and six detection indexes. D-(−)-lactic acid, glycerin, phosphoric acid, 5-oxo-L-proline were negatively correlated with TNF-α, and p values were statistically significant except for L-tyrosine. In addition, glycerin was negatively correlated with IL-6, PGE2 and MDA, while phosphoric acid was negatively correlated with IL-6. In conclusion, EA may play an antipyretic anti-inflammatory role through the inhibition of the IKB-α/NF-κB signaling pathway and five metabolic pathways, which may contribute to a further understanding of the therapeutic mechanisms of the fever of EA.

7.
Foods ; 10(10)2021 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-34681436

RESUMO

Volatile oils of prickly ash (Zanthoxylum) pericarps have various potential biological functions with considerable relevance to food, pharmacological, and industrial applications. The volatile profile of oils extracted from prickly ash pericarps obtained from 72 plantations in China was determined by gas chromatography and mass spectrometry. Several chemometric analyses were used to better understand the volatile oil profile differences among different pericarps and to determine the key factors that affected geographical variations in the main volatile constituents of oils. A total of 47 constituents were detected with D-limonene, alfa-myrcene, and linalool as the most abundant. The volatile profile of pericarp oils was significantly affected by prickly ash species and some environmental factors, and the key factors that affected volatile profile variations for different prickly ash species were diverse. Chemometric analyses based on the volatile oil profile could properly distinguish Z. armatum pericarps from other pericarps. This study provides comprehensive information on the volatile oil profile of pericarps from different prickly ash species and different plantations, and it can be beneficial to a system for evaluating of pericarp quality. Moreover, this study speculates on the key environmental factors that cause volatile oil variations for each species, and can help to obtain better prickly ash pericarp volatile oils by improving the cultivated environments.

8.
J Family Med Prim Care ; 9(10): 5252-5255, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-33409197

RESUMO

BACKGROUND: Caffeine use and abuse is a concern among treatment seekers for psychological problems. This aspect has not been documented an Indian context as well as its relevance in primary care setting. The aim of the present study was to explore and compare the caffeine intake and prevalence in Indian psychiatric patients and healthy subjects. MATERIALS AND METHODS: Caffeine analysis in urine samples was carried out using a gold technique, gas chromatograph and mass selective detectors. This analytical technique is highly sensitive for identification of unambiguous compound. Two hundred and forty-three subjects having psychiatric disorders, along with forty-two healthy subjects were included in the study. They were assessed by using structured interview for caffeine use and screened for substance dependence as well. RESULTS: One hundred twenty-eight subjects had history of substance use along with other comorbid psychiatric problems The mean of caffeine values was 1459 ± 1140 ng/mL, Whereas 42 subjects in control group (male 26, female 16) in the age group of 21-60 years had the mean caffeine levels of 1023 ± 788.8 ng/mL. The Caffeine use was significantly higher (P ≥ 0.84) in the subjects with psychiatric problems in comparison to the healthy subjects. CONCLUSIONS: It implies the need to enable and sensitize the primary care physicians in screening and educating treatment seekers with psychiatric morbidities for the management of caffeine use.

9.
J Chromatogr A ; 1611: 460616, 2020 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-31630832

RESUMO

A fluorinated metal-organic framework material (F-MOF) was successfully prepared using tetrafluoroterephthalic acid (H2tfbdc) as the ligand and Zn(II) as the central metal ion. The F-MOF exhibited excellent adsorption performance for perfluorooctanoic acid (PFOA), with a maximum adsorption capacity of 419.8 mg g-1. A sensitive dispersive solid-phase extraction using the F-MOF as an adsorbent, coupled with GC-MS analysis, was developed for detecting trace PFOA with a limit of detection as low as 2.6 ng L-1. This method was applied to detect PFOA in environmental water samples, yielding satisfactory results.


Assuntos
Caprilatos/química , Fluorocarbonos/química , Halogenação , Estruturas Metalorgânicas/síntese química , Extração em Fase Sólida/métodos , Adsorção , Cromatografia Gasosa-Espectrometria de Massas , Concentração de Íons de Hidrogênio , Lagos/química , Ligantes , Concentração Osmolar , Solventes/química , Termogravimetria , Fatores de Tempo , Água/química
10.
J Hazard Mater ; 384: 121430, 2020 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-31635818

RESUMO

A nitrogen-doped metal organic framework (MOF) based porous carbon (C-(C3N4@MOF)) was produced by the carbonization of a graphitic carbon nitride (g-C3N4) templated MOF (NH2-MIL-125). The C-(C3N4@MOF) was then coated on a stainless steel wire by sol-gel technique to serve as a solid-phase microextraction (SPME) fiber coating. The coated fiber was studied for the extraction of fourteen organophosphorous pesticides (OPPs) from different fruit and vegetable samples followed by gas chromatography-mass spectrometer (GC-MS) detection. The C-(C3N4@MOF) coated fiber exhibited a high extraction capability for the OPPs. Both single factor optimization and response surface analysis (Box-Behnken Design) methods were implemented to optimize the experiment conditions for the extraction. The results indicated that the linear response for the fourteen OPPs was in the range from 0.69 to 3000 ng g-1 and the coefficients of determination (r2) ranged from 0.9981 to 0.9998. The limits of detection (LODs, S/N = 3) ranged from 0.23 to 7.5 ng g-1. The method recoveries (R) of the fourteen OPPs for spiked fruit and vegetable samples were between 82.6% and 118%, with the relative standard deviations (RSDs) varying from 2.8% to 11.7%. The fiber can be reused over 100 times without a significant loss of extraction efficiency.


Assuntos
Contaminação de Alimentos/análise , Inseticidas/análise , Estruturas Metalorgânicas/química , Nitrilas/química , Compostos Organofosforados/análise , Carbono/química , Frutas/química , Magnoliopsida/química , Nitrogênio/química , Porosidade , Microextração em Fase Sólida , Verduras/química
11.
Transl Res ; 216: 23-29, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31585066

RESUMO

Our objective was to assess whether volatile organic compound (VOC) analysis of vaginal swabs can detect maternal Group B Streptococcus (GBS) during pregnancy in a prospective exploratory study. Around 243 women attending a high-risk antenatal clinic at one university teaching hospital in the UK consented to take part and provide vaginal swabs throughout pregnancy. VOC analysis of vaginal swabs was undertaken and compared with the reference standard of GBS detected using enrichment culture method. The chemical components that emanated from the vaginal swabs were measured by gas chromatograph ion mobility spectrometry. This platform has both high sensitivity and good specificity to a range of chemical compounds. Our main outcome was to determine the sensitivity and specificity of VOC analysis for the detection of maternal GBS in vaginal swabs during pregnancy. Our study has demonstrated that the sensitivity and specificity of the VOC analysis by GC-IMS for the detection of GBS from vaginal swabs was 0.81 (95% confidence interval [CI], 0.71-0.89) and 0.97 (95% CI, 0.91-1) respectively. We conclude that the use of VOCs as biomarkers for the detection of maternal GBS in the vagina is a novel tool. As this test produces results within minutes and is of low unit test cost, it has the potential to be used in clinical settings, where fast diagnosis is important, for example, a patient in early labour.


Assuntos
Streptococcus agalactiae/isolamento & purificação , Vagina/metabolismo , Compostos Orgânicos Voláteis/metabolismo , Adulto , Feminino , Humanos , Gravidez , Estudos Prospectivos
12.
J Chromatogr A ; 1589: 141-148, 2019 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-30642676

RESUMO

Thermal desorption aerosol gas chromatography (TAG) is an effective technique for online chemical characterization of organics in atmospheric fine particulate matter (PM2.5) on the molecular level. Unlike the previously reported impactor- or metal filter-based TAG, in this study, a replaceable quartz filter-based TAG (Q-TAG) was developed to achieve online measurement of organic constituents in ambient PM2.5. A homemade device for automatic online sampling and pretreatment of aerosols was developed and coupled with gas chromatography-mass spectrometry (GC-MS) by a 4-port valve. Performance of the Q-TAG system was evaluated using C7 - C40 n-alkanes to cover a wide range of volatility. C11 - C40 could be measured by Q-TAG. The response of their peaks depends on their volatility and thermal desorption conditions (the desorption time and the flow rate). Under the optimized conditions, good precision (<12%), acceptable linearity (R2> 0.98) and high sensitivity (detection limits from 0.02 to 0.01 ng) of C13 - C40 were obtained. The developed Q-TAG system was applied for online analysis of organic species in ambient PM2.5. The Q-TAG is suitable for detection of semi and low volatile organic species in particulate matter, and its filter can be easily changed, making it a useful tool in molecular characterization of ambient organic aerosols.


Assuntos
Aerossóis/análise , Cromatografia Gasosa-Espectrometria de Massas/métodos , Compostos Orgânicos/análise , Compostos Orgânicos Voláteis/análise , Poluentes Atmosféricos , Alcanos , Monitoramento Ambiental , Material Particulado , Quartzo
13.
J Chromatogr A ; 1585: 202-206, 2019 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-30514590

RESUMO

Magnetic hyperbranched polyamide amine (MHPA) was successfully prepared and applied as a QuEChERS adsorbent to the gas chromatograph-mass spectrometer (GC-MS) detection of organophosphorus pesticides (OPPs) in orange juice. Abundant in amino types and the structure of hyperbranched organic chains make MHPA to possess the clean-up function integrating classic clean-up agent primary secondary amine (PSA) with C18 modified silica, and the magnetic property makes the operation easier and more time-saving. Compared the performance with classical clean-up agents of PSA and C18, better results were obtained with MHPA as adsorbent for the detection of 11 OPPs. Recoveries ranged from 75.2 to 116.2% with the relative standard deviation (RSD) of 4.1-18.9% and the limit of detection (LOD) of 0.74-8.16 ng/g. Results showed that using MHPA as adsorbent for QuEChERS sample preparation is an effective alternative with simplicity and rapidity.


Assuntos
Aminas/química , Técnicas de Química Analítica/métodos , Análise de Alimentos/métodos , Organofosfatos/análise , Resíduos de Praguicidas/análise , Técnicas de Química Analítica/economia , Análise de Alimentos/economia , Análise de Alimentos/instrumentação , Cromatografia Gasosa-Espectrometria de Massas , Nylons/química , Organofosfatos/química , Resíduos de Praguicidas/química , Reprodutibilidade dos Testes
14.
J Forensic Sci ; 64(6): 1720-1725, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31674674

RESUMO

One of the most important contributions of forensic entomology is to assist criminal expertise to determine the postmortem interval, which depends on the duration of the immature stages of insects of forensic interest. On the other hand, the time of development of the different stages varies according to the species; therefore, its identification is essential. Currently, few studies have investigated the use of cuticular hydrocarbons, and none regarding fatty acids, as complementary taxonomic tools to expedite species identification. Therefore, we evaluated whether cuticular hydrocarbons together with fatty acids of eggs of flies of the family Calliphoridae, main group of forensic interest, can be used to distinguish species. The analyses were performed by chromatographic techniques. The results show that there are significant differences between the composition of cuticular hydrocarbons and fatty acids between species and, therefore, they can be used to provide a complementary taxonomic tool to expedite the forensic expertise.


Assuntos
Dípteros/metabolismo , Ácidos Graxos/metabolismo , Hidrocarbonetos/metabolismo , Óvulo/metabolismo , Escamas de Animais/metabolismo , Animais , Cromatografia , Análise Discriminante , Entomologia/métodos , Ciências Forenses , Especificidade da Espécie
15.
Methods Mol Biol ; 1875: 333-343, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30362015

RESUMO

In this chapter, we give an introduction to innovative attempts for the collection, identification, and statistical analysis of volatile organic compound (VOC) patterns emitted by phytoplasma-infected plants compared to healthy plants by the use of state-of-the-art techniques. This encompasses headspace-sampling techniques, gas chromatography coupled with mass spectrometry, and identification of VOC patterns by the "Automated Mass Spectral Deconvolution and Identification System" (AMDIS) followed by appropriate statistical analysis.


Assuntos
Phytoplasma/patogenicidade , Plantas/química , Compostos Orgânicos Voláteis/análise , Cromatografia Gasosa-Espectrometria de Massas , Plantas/microbiologia , Análise de Componente Principal , Software
16.
PeerJ ; 5: e3029, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28265508

RESUMO

INTRODUCTION: Rhizospheres, the most active interfaces between plants and soils, play a central role in the long-term maintenance of the biosphere. The anti-erodibility of soils (AES) regulated by the root exudates is crucial to the soil stability in the rhizospheres. However, scientists still debate (1) the key organic matter of the root exudates affecting the AES and (2) the interspecific variation of these root exudates. METHODS: We used an incubation of soils to test the effects of the root exudates from eight woody plant species on the change in soil aggregation and identified the organic matter in these root exudates with gas chromatography-mass spectrometry (GC-MS) and biochemical methods. Furthermore, the relationships between the organic matter in the exudates and the AES in the rhizospheres of 34 additional tree species were analyzed. RESULTS: The water-stable aggregates of the soils incubated with the root exudates increased by 15%-50% on average compared with control samples. The interspecific differences were significant. The root exudates included hundreds of specific organic matter types; hydrocarbon, total sugar, total amino acids, and phenolic compounds were crucial to the AES. These organic matter types could explain approximately 20-75% of the variation in the total effect of the root exudates on the AES, which was quantified based on the aggregate status, degree of aggregation, dispersion ratio, and dispersion coefficient. DISCUSSION: The effects of the root exudates on the AES and the interspecific variation are as important as that of root density, litters, and vegetation covers. Many studies explored the effects of root density, litters, vegetation covers, and vegetation types on the AES, but little attention has been paid to the effects of the root exudates on the AES. Different plants secrete different relative contents of organic matter resulting in the variation of the effect of the root exudates on the AES. Our study quantified the causal relationships between the root exudates and the AES using modeling experiments in laboratory and field observations and indicated the interspecific variation of the AES and organic matter of the root exudates. CONCLUSIONS: More organic compounds of the exudates related to the AES were recognized in this study. These results enhance the understanding of the soil stability at a slope and can be applied to ecosystem restoration.

17.
Sci Total Environ ; 466-467: 770-6, 2014 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-23973543

RESUMO

OBJECTIVE: To investigate the possible association between birth size or gestational length and maternal serum concentrations of hexachlorobenzene (HCB) in a population exposed to background levels. METHODS: A total of 1568 mother-child pairs recruited in three Spanish areas (INMA Project) from 2004 to 2008 participated in the study. Multivariate analysis was performed between birth weight and length, weeks of gestation, preterm birth or small for gestational age and HCB concentrations in maternal serum. RESULTS: The median concentration of HCB was 45.45 ng/g lipids. No association was found between HCB exposure levels and birth weight (ß: -50.42 [-109.88; 9.04]), birth length (ß: -0.07 [-0.32; 0.18]), gestation age (HR: 1.07 [0.94; 1.22]), small for gestational age (OR: 0.95 [0.56; 1.61]) and preterm birth (OR: 0.60 [0.29; 1.28]). Results remain similar after adjustment for other organochlorines. CONCLUSION: Our findings support the idea that exposure to low levels of HCB does not affect the intrauterine growth nor the duration of gestation.


Assuntos
Poluentes Ambientais/sangue , Poluentes Ambientais/toxicidade , Hexaclorobenzeno/sangue , Hexaclorobenzeno/toxicidade , Exposição Materna , Efeitos Tardios da Exposição Pré-Natal/epidemiologia , Adulto , Animais , Peso ao Nascer/efeitos dos fármacos , Estudos de Coortes , Estatura Cabeça-Cóccix , Monitoramento Ambiental , Feminino , Desenvolvimento Fetal/efeitos dos fármacos , Cromatografia Gasosa-Espectrometria de Massas , Idade Gestacional , Humanos , Hidrocarbonetos Clorados/sangue , Hidrocarbonetos Clorados/toxicidade , Recém-Nascido , Análise Multivariada , Gravidez , Primeiro Trimestre da Gravidez/efeitos dos fármacos , Nascimento Prematuro/induzido quimicamente , Nascimento Prematuro/epidemiologia , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Espanha , Adulto Jovem
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