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1.
Eur J Nutr ; 2020 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-32979077

RESUMO

PURPOSE: Docosahexaenoic acid (DHA) plays an essential role in brain, and its status is dependent on dietary intakes. School-aged children in rural China, who consume diets low in omega-3 polyunsaturated fatty acids, may benefit from DHA supplementation. Therefore, this trial was performed to examine the effect of 6-month DHA supplementation on executive functions (EFs) among healthy school-aged children in rural China. METHODS: A randomized, double-blind, placebo-controlled trial was conducted among 106 primary school children aged 7-12 years in rural China. Participants were randomized to receive either 300 mg/d DHA or placebo for 6 months. EFs including working memory and cognitive flexibility were evaluated at baseline, at 3 months and at 6 months, using Digit Span Backwards and Wisconsin card sorting test, respectively. Socio-demographic data were collected at baseline, and erythrocyte membrane fatty acids and serum neurotransmitters were measured at baseline and after 6-month intervention. RESULTS: Ninety-four children (88.7%) completed the study according to the protocol. Changes in erythrocyte membrane fatty acids indicated good compliance of the participants. There was no significant intervention effect on serum neurotransmitters. In two-factor ANCOVA, both groups showed a significant improvement in the Digit Span Backwards and the Wisconsin card sorting test from baseline to endpoint. However, no significant intervention effect was found on any EF scores. Linear regression analysis suggested no significant association between changes in erythrocyte DHA level with changes in any EF scores. CONCLUSIONS: Supplementation with 300 mg/d DHA for 6 months had no benefit on EFs including working memory and cognitive flexibility among healthy school-aged children. This trial was registered at clinicaltrials.gov as NCT02308930 on December 5, 2014.

2.
Mol Plant ; 13(6): 836-850, 2020 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-32087369

RESUMO

The ubiquitin-proteasome system (UPS) is an important post-translational regulatory mechanism that controls many cellular functions in eukaryotes. Here, we show that stable expression of P3 protein encoded by Rice grassy stunt virus (RGSV), a negative-strand RNA virus in the Bunyavirales, causes developmental abnormities similar to the disease symptoms caused by RGSV, such as dwarfing and excess tillering, in transgenic rice plants. We found that both transgenic expression of P3 and RGSV infection induce ubiquitination and UPS-dependent degradation of rice NUCLEAR RNA POLYMERASE D1a (OsNRPD1a), one of two orthologs of the largest subunit of plant-specific RNA polymerase IV (Pol IV), which is required for RNA-directed DNA methylation (RdDM). Furthermore, we identified a P3-inducible U-box type E3 ubiquitin ligase, designated as P3-inducible protein 1 (P3IP1), which interacts with OsNRPD1a and mediates its ubiquitination and UPS-dependent degradation in vitro and in vivo. Notably, both knockdown of OsNRPD1 and overexpression of P3IP1 in rice plants induced developmental phenotypes similar to RGSV disease symptomss. Taken together, our findings reveal a novel virulence mechanism whereby plant pathogens target host RNA Pol IV for UPS-dependent degradation to induce disease symptoms. Our study also identified an E3 ubiquitin ligase, which targets the RdDM compotent NRPD1 for UPS-mediated degradation in rice.

3.
J Plant Physiol ; 229: 41-52, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30032044

RESUMO

Trichome (also referred to as 'háo' in tea) is a key feature in both tea products and tea plant (Camellia sinensis) selection breeding. Although trichomes are used as a model for studying cell differentiation and have been well studied in many plant species, the regulation of trichome formation at the molecular level is poorly understood in tea plants. In the present study, the hairy and hairless tea plant cultivars Fudingdabaicha (FDDB) and Rongchunzao (RCZ), respectively, were used to study this mechanism. We characterised tea plant trichomes as unicellular and unbranched structures. High-throughput Illumina sequencing yielded approximately 277.0 million high-quality clean reads from the FDDB and RCZ cultivars. After de novo assembly, 161,444 unigenes were generated, with an average length of 937 bp. Among these unigenes, 81,425 were annotated using public databases, and 55,201 coding sequences and 4004 transcription factors (TFs) were identified. In total, 21,599 differentially expressed genes (DEGs) were identified between RCZ and FDDB, of which 10,785 DEGs were up-regulated and 10,814 DEGs were down-regulated. Genes involved in the DNA replication pathway were significantly enriched. Furthermore, between FDDB and RCZ, DEGs related to TFs, phytohormone signals, and cellulose synthesis were identified, suggesting that certain genes involved in these pathways are crucial for trichome initiation in tea plants. Together, the results of this study provide novel data to improve our understanding of the potential molecular mechanisms of trichome formation and lay a foundation for additional trichome studies in tea plants.


Assuntos
Camellia sinensis/genética , Brotos de Planta/genética , Transcriptoma/genética , Regulação da Expressão Gênica de Plantas , Proteínas de Plantas/genética , Fatores de Transcrição/genética , Tricomas/genética
4.
Huan Jing Ke Xue ; 37(1): 317-24, 2016 Jan 15.
Artigo em Chinês | MEDLINE | ID: mdl-27078973

RESUMO

In order to investigate and assess the distribution of pathalic acid easters (PAEs) in agricultural products from typical areas of the Pearl River Delta, South China, 131 agricultural products were sampled for determination of 6 PAEs priority pollutants classified by the U. S. EPA by GC-FID. The results showed that the total contents of the PAEs (sigma PAEs) in agricultural products samples ranged from nd to 79.86 mg x kg(-1) and the mean value was 2.84 mg x kg(-1), with the detected ratio of 98.5%. The average concentrations of sigma PAEs in different types of agricultural products were ordered by vegetables (3.03 mg x kg(-1)) > rice (2.52 mg x kg(-1)) > fruits (1.26 mg x kg(-1)). The mean concentration of PAEs distributed in the four typical cities of the Pearl River Delta, and decreased in the sequence of Zhuhai (6.53 mg x kg(-1)) > Dongguan (2.59 mg x kg(-1)) > Huizhou (1.53 mg x kg(-1)) > Zhongshan (1.12 mg x kg(-1)). Di-n-butyl phthalate (DBP), di-(2-ethylhexyl) phthalate (DEHP) and di-n-octyl phthalate (DnOP) contributed more than 90. 8% of the total PAEs in samples, and were the main components of PAEs in agricultural products from the Pearl River Delta, with higher percentage contents and detected ratio. Meanwhile, the average concentrations of sigma PAEs in cabbage mustard, lettuce occurred in Zhuhai and Dongguan cities, followed by lettuce and leaf lettuce in the corresponding DEHP from Zhuhai city, both exceeded the suggested standards in U.S.A. and Europe and were of high health risk. There were significant differences among 14 various vegetables in the contents of the 6 PAEs compounds, and the sigma PAEs contents in cabbage mustard and lettuce as part of leafy vegetables were higher than those in other vegetables, while the lowest were detected in flowering cabbage and edible amaranth. Therefore, the type of vegetables and its growing environment exposed to the atmosphere and soil were the main factors that significantly affected their accumulation of PAEs concentrations.


Assuntos
Ésteres/análise , Frutas/química , Ácidos Ftálicos/análise , Poluentes do Solo/análise , Verduras/química , Agricultura , China , Cidades , Dibutilftalato , Alface , Oryza , Medição de Risco , Rios , Solo
5.
Huan Jing Ke Xue ; 36(8): 2954-63, 2015 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-26592027

RESUMO

The contents of 17 Organochlorine pesticides (OCPs) of 605 samples collected from the surface of agriculture land from Pearl River Delta Economic Zone were determined by gas chromatography with electron capture detector (GC-ECD). The residual characteristics, sources and ecological risk of OCPs were also analyzed. The results showed that the detection rate of OCPs was 97.85%. The mean value of residue level was 20.67 microg x kg(-1), with the highest value of 649.33 microg x kg(-1). The main contaminants included DDTs, HCHs, endosulfan sulfate and methoxychlor. Compared with the soils of other cities, the levels of HCHs and DDTs in the studied area were arranged from low to middle levels. The OCPs were obviously regionally distributed. High content areas were mainly distributed in the central area with dense population, intense industrial and agricultural activities. The residue levels in different types of lands were significantly different: the arable land > garden land > woodland. Especially, the residue level was the highest in the vegetable land. Source analysis indicated that the HCHs might come from the use of lindane. DDTs in soil mainly came from early residues, but the dicofol might be the important source in partial area. Comparing the contents of HCHs and DDTs with our National Standard (GB 15618-2008), the qualified rates of the first and second standard of HCHs were 97.5% and 100%, respectively, and the DDTs were 95.5% and 97.7%, respectively. According to the risk assessment, DDTs may still have some potential ecological impact on the studied area.


Assuntos
Hidrocarbonetos Clorados/análise , Resíduos de Praguicidas/análise , Poluentes do Solo/análise , Solo/química , Agricultura , China , Cromatografia Gasosa , Cidades , DDT/análise , Hexaclorocicloexano/análise , Indústrias , Medição de Risco
6.
Huan Jing Ke Xue ; 36(6): 2283-91, 2015 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-26387337

RESUMO

In order to investigate and assess the pollution level of phthalic acid esters (PAEs) in farm soils and products from typical agricultural fields in areas of Zhongshan City, Guangdong Province, South China, 65 topsoil and 37 agricultural product samples were collected and contents of 6 PAEs compounds that classified by the U. S. Environmental Protection Agency (EPA) as priority pollutants were determined by the GC-FID. The results indicated that total contents of the PAEs (∑ PAEs) in soils ranged from 0. 14 to 1. 14 mg x kg(-1), and the mean value was 0.43 mg x kg(-1), with the detected ratio of 100%. Various concentrations of PAEs differed in three land-use types were ordered by vegetable soil > orchard soil > paddy soil. Comparing with six U.S. EPA priority pollutants of PAEs, the contents of Di-n-butyl phthalate (DBP) and Dimethyl phthalate ( DMP) in soils exceeded the control limits of PAEs in the American soil by 93.85% and 27.69% respectively, but the rest four PAEs compounds were lower than the control limits. Generally, the pollution level of soils contaminated by PAEs in agricultural fields of Zhongshan City was relatively low. The contents of 3 PAEs in agricultural products ranged from 0.15 to 3.15 mg x kg(-1) with the average of 1.12 mg x kg(-1), which was lower than the suggested standards in USA and Europe and with low health risk. Meanwhile, ∑ PAEs concentrations in vegetables were higher than those both in rice and fruits. DBP and DEHP were the main components of PAEs both in agricultural soils and products, with higher percentage contents and detected ratio. ∑ PAEs and DBP contents in various agricultural products-soils had a significantly positive correlation, with Pearson coefficients (r) in vegetables-vegetable soils were 0.81 (P = 0.000), 0.75 (P = 0.000), and corresponding r among rice-paddy soil and fruits-fruit soils were 0.74 (P = 0.036), 0.65 (P = 0.041) and 0.66 (P = 0.029), 0.78 (P = 0.045), respectively. Although there existed a significant difference for single PAEs compound accumulated by agricultural products, the ∑ PAEs bioconcentration factors of all agricultural products were above 1. Therefore, the accumulation characteristics of PAEs should be fully concerned when farm soil quality assessment is taken.


Assuntos
Agricultura , Dibutilftalato/análise , Ácidos Ftálicos/análise , Poluentes do Solo/análise , China , Cidades , Poluição Ambiental , Ésteres/análise , Frutas , Oryza , Solo/química , Verduras
8.
Sci Total Environ ; 447: 160-8, 2013 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-23380564

RESUMO

High levels of organochlorine pesticides (OCPs) such as hexachlorocyclohexanes (HCHs) and dichlorodiphenyltrichloroethanes (DDTs) have been found in soil of the Pearl River Delta (PRD), attributable to high pesticide application in this area. Consequently, the occurrence and environmental effect of HCHs and DDTs in the PRD have attracted considerable attention. However, study focusing on the influence of potential factors such as soil property on the environmental fate of HCHs and DDTs in the PRD has been rare. The present study aimed to investigate the impact of soil physiochemical properties on the distribution patterns and fate of soil HCHs and DDTs on a large spatial scale. Levels of HCHs (sum of α-, ß-, γ- and δ-HCH) and DDTs (sum of 1,1,1-trichloro-2,2-bis-(p-chlorophenyl)ethane (p,p'-DDT), 1,1-dichloro-2,2-bis-(p-chlorophenyl)ethane (p,p'-DDD), and 1,1-dichloro-2,2-bis-(p-chlorophenyl)ethylene (p,p'-DDE)) in 151 soil samples covering all areas of the PRD and physiochemical parameters related to soil properties including pH, total organic carbon (TOC), total Fe (TFe), DCB-Fe (DFe), amorphous-Fe (AFe), complexed-Fe (CFe), total Mn (TMn), DCB-Mn (DMn), amorphous-Mn (AMn), complexed-Mn (CMn) and cation exchange capacity (CEC) were determined. The residual levels of HCHs and DDTs in soils of the present study, which are mainly controlled by soil TOC and CFe content and varying spatially with land use types, may potentially pose ecological risk to plants and animals. On the other hand, transformation of soil HCHs may be affected by pH and DDT transformation correlated significantly with AFe and CFe. Currently, soil has become an important secondary source of OCPs and the re-emission potential of OCPs in soil was mainly affected by soil OCP concentrations and land use types.


Assuntos
Hidrocarbonetos Clorados/análise , Praguicidas/análise , Poluentes do Solo/análise , China , Diclorodifenil Dicloroetileno/análise , Monitoramento Ambiental , Sedimentos Geológicos/química , Hexaclorocicloexano/análise , Rios/química
9.
J Chin Med Assoc ; 75(6): 269-74, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-22721621

RESUMO

BACKGROUND: TRIM29 belongs to the tripartite motif (TRIM) protein family. It has been reported to be up-regulated or be down-regulated in many cancer types, suggesting the oncogenic function of TRIM29 may be depend on different molecular signaling pathway. It was found that ß-catenin function (a key molecule in the Wnt signaling pathway) was required for TRIM29's oncogenic effects. TRIM29 gene expression was also found to be heterogeneous in non-small-cell lung cancer (NSCLC) subtypes. In this study, the possible associations of TRIM29 expression with clinicopathological factors, prognosis, and ß-catenin in human NSCLC were analyzed. METHODS: TRIM29 and ß-catenin expression of tumor and adjacent normal tissues in 251 cases of NSCLC treated by surgery was detected by the Immunohistochemical method. The relationship between clinical pathological data, ß-catenin, and TRIM29 expression was analyzed. RESULTS: TRIM29 expression of tumor tissues was significantly higher than adjacent normal tissues. Expression of TRIM29 in squamous cell carcinoma (SC) tissues was positively correlated with abnormal expression of ß-catenin, histological grade, tumor-node-metastasis (TNM) stage, and lymph node metastasis and that was positively correlated with tumor size, histological grading, TNM stage and lymph node metastasis in adenocarcinoma (AC). TRIM29 expression in SC and AC was significantly different and the intensity of poorly differentiated SC was significantly higher than that of AC. High-expression of TRIM29, poorly differentiated grade, and high clinical stage were independent prognostic indicators. CONCLUSION: We considered that TRIM29 may play a reference role in distinguish poorly differentiated AC and SC of NSCLC, combining with CK5/6 and CK7, and it could improve postoperative assessment and have the reference value for clinical treatment. The interaction between TRIM29 and ß-catenin may participate in the development of lung SC.


Assuntos
Carcinoma Pulmonar de Células não Pequenas/patologia , Proteínas de Ligação a DNA/fisiologia , Neoplasias Pulmonares/patologia , Fatores de Transcrição/fisiologia , beta Catenina/fisiologia , Adenocarcinoma/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma Pulmonar de Células não Pequenas/etiologia , Carcinoma Pulmonar de Células não Pequenas/mortalidade , Carcinoma de Células Pequenas/etiologia , Carcinoma de Células Pequenas/patologia , Proteínas de Ligação a DNA/genética , Feminino , Humanos , Neoplasias Pulmonares/etiologia , Neoplasias Pulmonares/mortalidade , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Fatores de Transcrição/genética , beta Catenina/genética
13.
Zhonghua Yi Xue Za Zhi ; 91(35): 2501-5, 2011 Sep 20.
Artigo em Chinês | MEDLINE | ID: mdl-22321850

RESUMO

OBJECTIVE: To investigate the effects of Ginkgo biloba extract (GBE) on the expression of endothelial nitric oxide synthase (eNOS) and the release of nitric oxide (NO) in mesenteric arterioles of aging rats. METHODS: (1) Cytologic experiment:human umbilical vein endothelial cells (HUVEC) were randomly divided into 3 groups: control group, NG-nitro-L-arginine methyl ester (L-NAME) group and GBE group. L-NAME group: 100 µmol/L L-NAME was added into HUNEC for a 48-hour incubation. GBE group: After HUVEC was exposed to 100 µmol/L L-NAME for 24 hours, 20 g/L GBE was added for another 24-hour co-incubation. Then the expression of eNOS protein was observed in each group. (2) Animal experiment: Thirty-two 24-month-old male SD rats were randomly divided into normal control group (n = 8) and GBE group (n = 24). The GBE group was further divided into 3 groups receiving an orally dosed GBE for 3, 5, 7 days respectively. Afterward the diameter of first-order mesenteric arteriole was measured under the pressures of 20, 40, 60, 80, 100, 120, 140 mm Hg (1 mm Hg = 0.133 kPa) and the elasticity of blood vessels calculated. The release of NO, the expression of eNOS protein and its mRNA in mesenteric arterioles stimulated by the same shear stress (15 dyn/cm(2)) were evaluated respectively. RESULTS: (1) Cytological studies indicated that the expression of eNOS protein of the L-NAME group was significantly lower than those of the control and GBE groups (0.57 ± 0.06 vs 0.96 ± 0.05, 0.81 ± 0.09, both P < 0.01). (2) After the dosing of GBE for 3, 5, 7 days, the release of NO was significantly higher than that of the control group [(8.01 ± 0.24, 12.11 ± 0.78, 14.72 ± 0.70 vs 5.83 ± 0.75) pmol×mm(-2)×min(-1), all P < 0.05]; the expressions of eNOS protein were significantly higher than those of the control group (0.59 ± 0.20, 0.86 ± 0.02, 1.09 ± 0.13 vs 0.41 ± 0.16, all P < 0.05). And GBE was highest at Day 7; the expression levels of eNOS mRNA were significantly higher than those of the control group (0.79 ± 0.04, 0.85 ± 0.07, 0.99 ± 0.03 vs 0.58 ± 0.05, all P < 0.05). And GBE was also highest at Day 7. CONCLUSION: GBE can improve vascular flexibility through increasing the expression of eNOS and the release of NO, protecting the functions of blood vessels.


Assuntos
Arteríolas , Óxido Nítrico , Animais , Ginkgo biloba , Humanos , NG-Nitroarginina Metil Éster , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase/metabolismo , Ratos , Ratos Sprague-Dawley
15.
Int J Surg Pathol ; 18(5): 363-8, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20667924

RESUMO

Here, the authors describe a case of giant-cell anaplastic carcinoma with osteoclastic giant cells of the chest cavity-which could be a distinctive form of thymic carcinoma-which expressed CD5 and CD45. To the authors' knowledge, there has been no previous report on this subject. A 62-year-old woman presented with continuous pain in the left back associated with coughing and shortness of breath for more than 2 months prior to referral to the hospital. Palliative resection of a mediastinal tumor was performed. During the operation, it was found that the mass occupied most of the chest invading the chest wall, aorta, vena cava, and lung tissue. The patient soon died from diabetic complications in spite of anti-infection treatment. The tumor was composed of large areas of necrosis and anaplastic neoplastic giant cells with high mitotic activity, and osteoclast-like cells; there was marked inflammatory cell infiltration. The anaplastic neoplastic giant cells were immunoreactive for CKpan, CD5, CD45, VIM, and p53. Approximately 50% to 60% of the tumor cells showed immunoreactivity for Ki-67. In situ hybridization for Epstein-Barr virus-encoded RNA was negative for tumor cells and nonneoplastic osteoclastic giant cells. Because this tumor is very rare, extensive clinical, radiological, and morphological examinations as well as immunohistochemical studies are essential to make the diagnosis.


Assuntos
Carcinoma/patologia , Osteoclastos/patologia , Cavidade Torácica/patologia , Neoplasias Torácicas/patologia , Neoplasias do Timo/patologia , Biomarcadores Tumorais/metabolismo , Antígenos CD5/metabolismo , Carcinoma/metabolismo , Carcinoma/cirurgia , Evolução Fatal , Feminino , Humanos , Antígenos Comuns de Leucócito/metabolismo , Pessoa de Meia-Idade , Cuidados Paliativos , Neoplasias Torácicas/metabolismo , Neoplasias Torácicas/cirurgia , Neoplasias do Timo/metabolismo , Neoplasias do Timo/cirurgia
17.
Environ Monit Assess ; 139(1-3): 61-76, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17665143

RESUMO

The concentrations, distribution and sources of 16 polycyclic aromatic hydrocarbons (PAHs) were determined in 30 agricultural soil and 16 vegetable samples collected from subtropical Shunde area, an important manufacturing center in China. The total PAHs ranged from 33.7 to 350 microg/kg in soils, and 82 to 1,258 microg/kg in vegetables. The most abundant individual PAHs are phenanthrene, fluoranthene, chrysene, pyrene and benzo(b)fluoranthene for soil samples, and anthracene, naphthalene, phenanthrene, pyrene and chrysene for vegetable samples. Average vegetable-soil ratios of total PAHs were 2.20 for leafy vegetables and 1.27 for fruity vegetables. Total PAHs in vegetable samples are not significantly correlated to those in corresponding soil samples. Principal component analyses were conducted to distinguish samples on basis of their distribution in each town, soil type and vegetable specie. Relatively abundant soil PAHs were found in town Jun'an, Beijiao, Chencun, Lecong and Ronggui, while abundant vegetable PAHs were observed in town Jun'an, Lecong, Xingtan, Daliang and Chenchun. The highest level of total PAHs were found in vegetable soil, followed by pond sediment and "stacked soil" on pond banks. The PAHs contents in leafy vegetables are higher than those in fruity vegetables. Some PAH compound ratios suggest the PAHs derived from incomplete combustion of petroleum, coal and refuse from power generation and ceramic manufacturing, and paint spraying on furniture, as well as sewage irrigation from textile industries. Soil PAHs contents have significant logarithmic correlation with total organic carbon, which demonstrates the importance of soil organic matter as sorbent to prevent losses of PAHs.


Assuntos
Agricultura , Compostos Policíclicos/análise , Poluentes do Solo/análise , Verduras/química , China , Cromatografia Gasosa-Espectrometria de Massas
18.
Huan Jing Ke Xue ; 28(5): 1067-74, 2007 May.
Artigo em Chinês | MEDLINE | ID: mdl-17633181

RESUMO

Distribution of Copper (Cu), Zinc (Zn), Nickel (Ni), Lead (Pb), Chromium (Cr), Cadmium (Cd), Arsenic (As), and Mercury (Hg) in soils from the typical regions of Shantou such as electrical wastes recycling sites were studied, and pollution risk of heavy metals on the environment was evaluated. Among the 118 surface soil samples, 42 (corresponding to 35.6%) were above the national standards when evaluated with single factor index method. Specifically, Ni, Cu, Hg, and As exceeded the standards by 26.3%, 18.6%, 7.6%, and 0.85%, respectively. Among the 20 samples from five section soil sites, 7 (corresponding to 35.0%) were above the national standards with Ni, Hg, and Cu exceeding respectively by 20.0%, 15.0%, and 10.0%. The composite pollution index of all samples ranged from 0.32 to 6.08, with an average of 1.26. Overall, 39.1% of soils were polluted, and which composed of heavily (7.2%), moderately (10.9%), and lightly (21.0%) contaminated soils. The highest composite pollution index (1.98) was found in Chaoyang district, followed with descending order by Jinping, Chenghai, Chaonan, Longhu, Haojiang districts, and Nanao town. Pollution, industrial and agricultural wastes, and contaminated irrigation water were the main sources of heavy metal contamination in soils. Except for Cr and As, concentrations of Cu, Pb, and Hg in soils from Shantou districts were much higher than the corresponding soil background concentrations recorded for Guangdong province, China, and the whole world. Controlling heavy metal output from industrial and agricultural sources and reducing the concentrations of soil heavy metals through integrated treatment techniques are the effective methods to improve the soil quality in Shantou.


Assuntos
Monitoramento Ambiental/métodos , Metais Pesados/análise , Poluentes do Solo/análise , Solo/análise , China , Cobre/análise , Chumbo/análise , Mercúrio/análise
19.
Ying Yong Sheng Tai Xue Bao ; 18(10): 2308-12, 2007 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-18163315

RESUMO

To understand the distribution characteristics of phthalic acid esters (PAEs) in agricultural soils in typical regions of Guangdong Province, surface soil (0-20 cm) samples were collected, and the concentrations of 6 PAEs were determined by gas chromatography. The results showed that the total concentration of the PAEs (sigma PAEs) ranged from not detected to 25.99 mg x kg(-1), and was < or = 1.00 mg x kg(-1) in 92.8% of the samples. The sigma PAEs differed with land use types and regions, and decreased in the sequences of paddy soil > banana soil > vegetable soil > sugarcane soil > orchard soil, and Dongguan > Shantou > Shunde > Zhanjiang > Zhongshan > Zhuhai > Huizhou. Among the test PAEs, DEHP had the highest detection rate (85.1%), DnBP had the highest concentration (not detected to 17.51 mg x kg(-1)). Comparing with the corresponding control limits of soil PAEs in USA, all test PAEs except DnOP were exceeded the limits to some extent, and DnBP, DMP and DEP exceeded seriously, indicating that the agricultural soils in the typical regions of Guangdong Province were contaminated by PAEs.


Assuntos
Produtos Agrícolas/crescimento & desenvolvimento , Ácidos Ftálicos/análise , Poluentes do Solo/análise , China , Dietilexilftalato/análise , Monitoramento Ambiental , Solo/análise
20.
Huan Jing Ke Xue ; 28(10): 2350-4, 2007 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-18269004

RESUMO

260 samples of surface agricultural soils (0-20 cm depth) were collected in the typical areas of Pearl River Delta from October 2002 to November 2005. The concentrations of polycyclic aromatic hydrocarbons (16 US EPA priority PAHs) in the collected soil samples were determined by gas chromatography equipped with a mass spectrometry detector (GC-MS). The results showed that the concentrations of Sigma PAHs in the collected soil samples ranged from 3.3 to 4,079.0 ng x g(-1) with the average concentration of 224.2 ng x g(-1). PAHs in the collected samples were dominated by its 3-ring and 4-ring members. There were the higher concentrations of Sigma PAHs in the collected samples of urban sites than those of remote sites. The concentrations of PAHs in the collected samples related to different land use types the order: vegetable soils > paddy soils > banana soils > orchard soils > sugarcane soils. According to the distributions of fluoranthene/pyrene, 2 + 3 ring and 4 ring PAHs in these regions, it is supposed that the major contribution to the pollution of PAHs in these typical areas might be the incomplete combustion of fossil fuel. Compared with those in other national or international regions, the concentrations of Sigma PAHs in these typical regions were moderate.


Assuntos
Produtos Agrícolas/crescimento & desenvolvimento , Monitoramento Ambiental/métodos , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes do Solo/análise , China , Cromatografia Gasosa-Espectrometria de Massas , Solo/análise
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