Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 20
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Sci Data ; 11(1): 666, 2024 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-38909049

RESUMEN

High-quality ocean in situ profile observations are fundamental for ocean and climate research and operational oceanographic applications. Here we describe a new global ocean subsurface temperature profile database named the Chinese Academy of Science (CAS) Oceanography Data Center version 1 (CODC-v1). This database contains over 17 million temperature profiles between 1940-2023 from all available instruments. The major data source is the World Ocean Database (WOD), but CODC-v1 also includes some data from some Chinese institutes which are not available in WOD. The data are quality-controlled (QC-ed) by a new QC system that considers the skewness of local temperature distributions, topographic barriers, and the shift of temperature distributions due to climate change. Biases in Mechanical Bathythermographs (MBTs), eXpendable Bathythermographs (XBTs), and Bottle data (OSD) are all corrected using recently proposed correction schemes, which makes CODC-v1 a bias-corrected dataset. These aspects ensure the data quality of the CODC-v1 database, making it suitable for a wide spectrum of ocean and climate research and applications.

2.
Int J Antimicrob Agents ; 63(4): 107101, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38325722

RESUMEN

BACKGROUND: Resistance to extended-spectrum cephalosporins (ESCs) has become a public health concern with the spread of Neisseria gonorrhoeae and increasing antimicrobial resistance. Mutation of penA, encoding penicillin-binding protein 2, represents a mechanism of ESC resistance. This study sought to assess penA alleles and mutations associated with decreased susceptibility (DS) to ESCs in N. gonorrhoeae. MATERIALS AND METHODS: In 2021, 347 gonococci were collected in Guangdong, China. Minimum inhibitory concentations (MICs) of ceftriaxone and cefixime were determined, and whole-genome sequencing and phylogenetic analysis were performed. Multi-locus sequence typing (MLST) and conventional resistance determinants such as penA, mtrR, PonA and PorB were analysed. penA was genotyped and sequence-aligned using PubMLST. RESULTS: Genome-wide phylogenetic analysis revealed that the prevalence of DS to ESCs was highest in Clade 11.1 (100.0%), Clade 2 (66.7%) and Clade 0 (55.7%), and the leading cause was strains with penA-60.001 or new penA alleles in clades. The penA phylogenetic tree is divided into two branches: non-mosaic penA and mosaic penA. The latter contained penA-60.001, penA-10 and penA-34. penA profile analysis indicated that A311V and T483S are closely related to DS to ESCs in mosaic penA. The new alleles NEIS1753_2840 and NEIS1753_2837 are closely related to penA-60.001, with DS to ceftriaxone and cefixime of 100%. NEIS1753_2660, a derivative of penA-10 (A486V), has increased DS to ceftriaxone. NEIS1753_2846, a derivative of penA-34.007 (G546S), has increased DS to cefixime. CONCLUSION: This study identified critical penA alleles related to elevated MICs, and trends of gonococcus-evolved mutated penA associated with DS to ESCs in Guangdong.


Asunto(s)
Ceftriaxona , Gonorrea , Humanos , Ceftriaxona/farmacología , Cefixima/farmacología , Neisseria gonorrhoeae/genética , Antibacterianos/farmacología , Tipificación de Secuencias Multilocus , Alelos , Filogenia , Gonorrea/tratamiento farmacológico , Gonorrea/epidemiología , Pruebas de Sensibilidad Microbiana , Cefalosporinas/farmacología , China/epidemiología
3.
Environ Monit Assess ; 196(2): 214, 2024 Jan 29.
Artículo en Inglés | MEDLINE | ID: mdl-38286925

RESUMEN

Two physical models were used to simulate the infiltration and redistribution process of light crude oil after leakage in a heterogeneous soil layer following water level variation and rainfall. Migration fronts and redistribution characteristics of oil during gravity seepage, water level variation, and rainfall were obtained using charge-coupled device (CCD) camera shooting and cyan-magenta-yellow‒black (CMYK)-based gray analysis, which were employed efficiently and at a low cost. Then, the influencing factors and migration mechanisms were examined. Finally, the soil water and oil contents were measured to verify the simulation results. The results are as follows: (1) the geologic lens and fine-coarse interface can intercept oil, resulting in a local highly contaminated area. (2) The crude oil infiltration path and velocity varied greatly with the different soil types and initial water contents. Within a certain range, the higher the initial water content is, the higher the lateral and vertical infiltration speeds. (3) The oil redistribution process was dominated by vertical infiltration under the condition of water level variation or rainfall, but oil-water displacement and the capillary pressure caused some oil to move horizontally near the geologic lens and fine-coarse interface. (4) Water level variation resulted in a synchronous rise or fall of the oil accumulation area, but rainfall caused it to move up. (5) Water level variation and rainfall imposed a certain influence on the periodic accumulation and release of crude oil in heterogeneous soil, especially in the presence of geologic lenses and lithologic interfaces.


Asunto(s)
Petróleo , Petróleo/análisis , Suelo , Lluvia , Monitoreo del Ambiente , Agua/análisis , Movimientos del Agua
4.
Microbiol Spectr ; 12(1): e0224623, 2024 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-38047697

RESUMEN

IMPORTANCE: Tuberculous meningitis is a life-threatening infection with high mortality and disability rates. Current diagnostic methods using cerebrospinal fluid (CSF) samples have limited sensitivity and lack predictive biomarkers for evaluating prognosis. This study's findings reveal excessive activation of the immune response during tuberculous meningitis (TBM) infection. Notably, a strong negative correlation was observed between CSF levels of monokine induced by interferon-γ (MIG) and the CSF/blood glucose ratio in TBM patients. MIG also exhibited the highest area under the curve with high sensitivity and specificity. This study suggests that MIG may serve as a novel biomarker for differentiating TBM infection in CSF or serum, potentially leading to improved diagnostic accuracy and better patient outcomes.


Asunto(s)
Tuberculosis Meníngea , Humanos , Tuberculosis Meníngea/diagnóstico , Tuberculosis Meníngea/tratamiento farmacológico , Curva ROC , Interferón gamma , Suero , Biomarcadores , Líquido Cefalorraquídeo
5.
Microbiol Spectr ; 11(6): e0046423, 2023 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-37882532

RESUMEN

IMPORTANCE: A method for Neisseria gonorrhoeae (NG)/Chlamydia trachomatis (CT) detection is developed using multiplex-recombinase polymerase amplification and Cas12a/Cas13a. This method can detect NG and CT simultaneously with high sensitivity and specificity. This method has great potential to be further developed into larger-scale screening and point-of-care testing (POCT).


Asunto(s)
Infecciones por Chlamydia , Gonorrea , Humanos , Neisseria gonorrhoeae/genética , Chlamydia trachomatis/genética , Gonorrea/diagnóstico , Infecciones por Chlamydia/diagnóstico , Sensibilidad y Especificidad
6.
J Clin Microbiol ; 61(6): e0188422, 2023 06 20.
Artículo en Inglés | MEDLINE | ID: mdl-37195177

RESUMEN

The quantitative detection of drug-resistance mutations in Mycobacterium tuberculosis (MTB) is critical for determining the drug resistance status of a sample. We developed a drop-off droplet digital PCR (ddPCR) assay targeting all major isoniazid (INH)-resistant mutations. The ddPCR assay consisted of three reactions: reaction A detects mutations at katG S315; reaction B detects inhA promoter mutations; and reaction C detects ahpC promoter mutations. All reactions could quantify 1%-50% of mutants in the presence of the wild-type, ranging from 100 to 50,000 copies/reaction. Clinical evaluation with 338 clinical isolates yielded clinical sensitivity of 94.5% (95% confidence interval [CI] = 89.1%-97.3%) and clinical specificity of 97.6% (95% CI = 94.6%-99.0%) compared with the traditional drug susceptibility testing (DST). Further clinical evaluation using 194 nucleic acid-positive MTB sputum samples revealed clinical sensitivity of 87.8% (95% CI = 75.8%-94.3%) and clinical specificity of 96.5% (95% CI = 92.2%-98.5%) in comparison with DST. All the mutant and heteroresistant samples detected by the ddPCR assay but susceptible by DST were confirmed by combined molecular assays, including Sanger sequencing, mutant-enriched Sanger sequencing and a commercial melting curve analysis-based assay. Finally, the ddPCR assay was used to monitor longitudinally the INH-resistance status and the bacterial load in nine patients undergoing treatment. Overall, the developed ddPCR assay could be an indispensable tool for quantification of INH-resistant mutations in MTB and bacterial loads in patients.


Asunto(s)
Mycobacterium tuberculosis , Tuberculosis Resistente a Múltiples Medicamentos , Humanos , Isoniazida/farmacología , Mycobacterium tuberculosis/genética , Antituberculosos/farmacología , Pruebas de Sensibilidad Microbiana , Sensibilidad y Especificidad , Reacción en Cadena de la Polimerasa , Mutación , Tuberculosis Resistente a Múltiples Medicamentos/microbiología , Proteínas Bacterianas/genética
7.
Ann Clin Microbiol Antimicrob ; 22(1): 39, 2023 May 17.
Artículo en Inglés | MEDLINE | ID: mdl-37198645

RESUMEN

BACKGROUND: Antimicrobial resistance (AMR) of untreatable gonococcal infection is an emerging threat, especially in Guangdong, a prosperous province in Southern China. METHODS: N.gonorrhoeae was isolated from 20 cities in Guangdong and determined antimicrobial susceptibility. Through whole-genome sequencing (WGS), multilocus sequence typing (MLST), N.gonorrhoeae multiantigen sequence typing (NG-MAST), and N.gonorrhoeae sequence typing for antimicrobial resistance (NG-STAR) were obtained based on the PubMLST database ( https://pubmlst.org/ ). Phylogenetic analysis was used for dissemination and tracking analysis. RESULTS: Antimicrobial susceptibility was performed on 347 isolates, and 50 isolates were identified as decreased susceptibility (DS) to cephalosporins. Of which 16.0% (8/50) were ceftriaxone DS, 38.0% (19/50) were cefixime DS, and 46.0% (23/50) were both ceftriaxone and cefixime DS. In all, the dual-resistant rate of the cephalosporin-DS isolates was 96.0% for penicillin and 98.0% for tetracycline-resistant, and 10.0% (5/50) were resistant to azithromycin. All cephalosporin-DS isolates were resistant to ciprofloxacin but sensitive to spectinomycin. The predominant MLSTs were ST7363 (16%, 8/50), ST1903 (14%, 7/50), ST1901 (12%, 6/50), and ST7365 (10%, 5/50). Besides some isolates that failed genotyping (NA), NG-STAR ST1143 (n = 6) and NG-MAST ST17748 (n = 4) were the most prevalent. Twelve isolates with mosaic penA-60.001 allele retained the most elevated cephalosporin MIC (Minimum Inhibitory Concentration). Phylogenetic analysis revealed that epidemic penA-60.001 clones, either domestic or foreign, had spread to nine cities in Guangdong, and 9/12 clones were from the Pearl River Delta region. CONCLUSIONS: N. gonorrhoeae with cephalosporins-DS was extensively disseminated in Guangdong, Southern China, requiring strict surveillance.


Asunto(s)
Cefalosporinas , Gonorrea , Humanos , Cefalosporinas/farmacología , Neisseria gonorrhoeae/genética , Ceftriaxona/farmacología , Cefixima/farmacología , Tipificación de Secuencias Multilocus , Filogenia , Ciudades , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Gonorrea/epidemiología , Gonorrea/tratamiento farmacológico , Pruebas de Sensibilidad Microbiana
8.
J Contam Hydrol ; 250: 104077, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-36156379

RESUMEN

Under tidal scouring, residual petroleum in the intertidal sediment after oil spills could release again, causing secondary pollution in the marine ecosystem. The current study aimed to investigate the dynamic process and principles of crude oil release from silty intertidal sediment under different influencing factors and screened for the key factors. In this paper, the fitting equations and correlation between the release amount and various factors were explored through the single-factor and orthogonal experiments. Then, the key influencing factors were selected for multi-factor fitting of the release amount. The results showed that the oil release amount rose with the increase in oil concentration, oscillation frequency, and release time, but decreased with an increase in salinity. As the pH decreased, the oil release amount increased. The relationship between release amount and concentration/oscillation frequency can be equipped by the polynomial equation, and the average R2 was 0.95 and 0.84, respectively. The release amount can be fitted by the Lagergren pseudo-second-order kinetic equation with time, with the average R2 0.89. The pH was negatively correlated with the release amount in the fresh contaminated sediment but positively correlated with the weathered one. The correlation between each factor and oil release amount was ranked (from large to small) as oil concentration, oscillation frequency, salinity, time, and pH. At last, a polynomial equation can be fitted between the key influencing factors (oil concentration and oscillation frequency) and the release amount. The results can provide a theoretical basis for predicting the secondary pollution owing to the oil re-release from intertidal sediment.


Asunto(s)
Contaminación por Petróleo , Petróleo , Contaminantes Químicos del Agua , Ecosistema , Sedimentos Geológicos , Contaminación por Petróleo/análisis , Contaminantes Químicos del Agua/análisis
9.
Nat Commun ; 13(1): 4671, 2022 08 09.
Artículo en Inglés | MEDLINE | ID: mdl-35945210

RESUMEN

The performance of commonly used assays for diagnosis of syphilis varies considerably depending on stage of infection and sample type. In response to the need for improved syphilis diagnostics, we develop assays that pair PCR pre-amplification of the tpp47 gene of Treponema pallidum subsp. pallidum with CRISPR-LwCas13a. The PCR-LwCas13a assay achieves an order of magnitude better analytical sensitivity than real-time PCR with equivalent specificity. When applied to a panel of 216 biological specimens, including 135 clinically confirmed primary and secondary syphilis samples, the PCR-LwCas13a assay demonstrates 93.3% clinical sensitivity and 100% specificity, outperforming tpp47 real-time PCR and rabbit-infectivity testing. We further adapt this approach to distinguish Treponema pallidum subsp. pallidum lineages and identify genetic markers of macrolide resistance. Our study demonstrates the potential of CRISPR-based approaches to improve diagnosis and epidemiological surveillance of syphilis.


Asunto(s)
Sífilis , Treponema pallidum , Animales , Antibacterianos/farmacología , Farmacorresistencia Bacteriana/genética , Genotipo , Macrólidos , Conejos , Reacción en Cadena en Tiempo Real de la Polimerasa , Sensibilidad y Especificidad , Sífilis/diagnóstico , Treponema , Treponema pallidum/genética
10.
Foods ; 11(6)2022 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-35327200

RESUMEN

Rapeseed is the third largest oil crop in the world and the largest oil crop in China. The multi-functional development and utilization of rapeseed is an effective measure for the high-quality development of rapeseed industry in China. In this study, several basic nutrients of eight rapeseed sprouts and five bean sprouts (3-5 varieties each) were determined, including sugar, crude protein, crude fiber, vitamin E, minerals, fatty acids, amino acids, and glucosinolates. Data analysis revealed that compared with bean sprouts, rapeseed sprouts were nutritionally balanced and were richer in active nutrients such as glucose, magnesium, selenium, vitamin E, and glucosinolate. Moreover, rapeseed sprouts exhibited reasonable amino acid composition and abundant unsaturated fatty acids (accounting for 90.32% of the total fatty acids). All these results indicated the potential of rapeseed sprout as a functional vegetable. Subsequently, three dominant nutrients including vitamin E, glucosinolate, and selenium were investigated in seeds and sprouts of 44 B. napus L. varieties. The results showed that germination raised the ratio of α-tocopherol/γ-tocopherol from 0.53 in seeds to 9.65 in sprouts, greatly increasing the content of α-tocopherol with the strongest antioxidant activity among the eight isomers of vitamin E. Furthermore, germination promoted the conversion and accumulation of glucosinolate components, especially, glucoraphanin with strong anti-cancer activity with its proportion increased from 1.06% in seeds to 1.62% in sprouts. In addition, the contents of selenium, vitamin E, and glucosinolate in rapeseed sprouts were highly correlated with those in seeds. Furthermore, these three dominant nutrients varied greatly within B. napus varieties, indicating the great potential of rapeseed sprouts to be further bio-enhanced. Our findings provide reference for the multi-purpose development and utilization of rapeseed, lay a theoretical foundation for the development of rapeseed sprout into a functional vegetable, and provide a novel breeding direction.

11.
Pharm Biol ; 60(1): 359-373, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-35171063

RESUMEN

CONTEXT: Patients with non-alcoholic steatohepatitis (NASH) may have a simultaneous intake of pravastatin and evodiamine-containing herbs. OBJECTIVE: The effect of evodiamine on the pharmacokinetics of pravastatin and its potential mechanisms were investigated in NASH rats. MATERIALS AND METHODS: The NASH model was conducted with feeding a methionine choline-deficient (MCD) diet for 8 weeks. Sprague-Dawley rats were randomised equally (n = 6) into NASH group, evodiamine group (10 mg/kg), pravastatin group (10 mg/kg), and evodiamine (10 mg/kg) + pravastatin (10 mg/kg) group. Normal control rats were fed a standard diet. Effects of evodiamine on the pharmacokinetics, distribution, and uptake of pravastatin were investigated. RESULTS: Evodiamine decreased Cmax (159.43 ± 26.63 vs. 125.61 ± 22.17 µg/L), AUC0-t (18.17 ± 2.52 vs. 14.91 ± 2.03 mg/min/L) and AUC0-∞ (22.99 ± 2.62 vs. 19.50 ± 2.31 mg/min/L) of orally administered pravastatin in NASH rats, but had no significant effect in normal rats. Evodiamine enhanced the uptake (from 154.85 ± 23.17 to 198.48 ± 26.31 pmol/mg protein) and distribution (from 736.61 ± 108.07 to 911.89 ± 124.64 ng/g tissue) of pravastatin in NASH rat liver. The expression of Oatp1a1, Oatp1a4, and Oatp1b2 was up-regulated 1.48-, 1.38-, and 1.51-fold by evodiamine. Evodiamine decreased the levels of IL-1ß, IL-6, and TNF-α by 27.82%, 24.76%, and 29.72% in NASH rats, respectively. DISCUSSION AND CONCLUSIONS: Evodiamine decreased the systemic exposure of pravastatin by up-regulating the expression of OATPs. These results provide a reference for further validation of this interaction in humans.


Asunto(s)
Enfermedad del Hígado Graso no Alcohólico/tratamiento farmacológico , Transportadores de Anión Orgánico/genética , Pravastatina/farmacocinética , Quinazolinas/farmacología , Animales , Área Bajo la Curva , Interacciones de Hierba-Droga , Inhibidores de Hidroximetilglutaril-CoA Reductasas/farmacocinética , Masculino , Ratas , Ratas Sprague-Dawley , Regulación hacia Arriba/efectos de los fármacos
12.
Environ Pollut ; 292(Pt A): 118341, 2022 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-34637832

RESUMEN

With the development of marine oil industry, oil spill accidents will inevitably occur, further polluting the intertidal zone and causing biological poisoning. The muddy intertidal zone and Boleophthalmus pectinirostris were selected as the research objects to conduct indoor acute exposure experiments within 48 h of crude oil pollution. Statistical analysis was used to reveal the activity changes of superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx) and glutathione S-transferase (GST) in the gills and liver of mudskipper. Then, integrated biomarker response (IBR) indicators were established to comprehensively evaluate the biological toxicity. The results showed that the activities of SOD, CAT and GST in livers were higher than those in gills, and the maximum induction multipliers of SOD, CAT and GPx in livers appeared earlier than those in gills. Both SOD and GPx activities were induced at low pollutant concentrations and inhibited at high pollutant concentrations. For the dose-effect, the change trends of CAT and SOD were roughly inversed. There was substrate competition between GPx and CAT, with opposite trends over time. The activating mechanism of GST was similar to that of GPx, and the activation time was earlier than that of GPx. In terms of dose-effect trends, the IBR showed that the antioxidant enzymes activities in biological tissues were induced by low and inhibited by high pollutant concentrations. Overall, SOD and GPx in gills and CAT and GST in livers of the mudskippers were suitable as representative markers to comprehensively analyze and evaluate the biotoxicity effects of oil pollution in the intertidal zone. The star plots and IBR values obtained after data standardization were consistent with the enzyme activity differences, which can be used as valid supplementary indexes for biotoxicity evaluation. These research findings provide theoretical support for early indicators of biological toxicity after crude oil pollution in intertidal zones.


Asunto(s)
Antioxidantes , Petróleo , Animales , Biomarcadores/metabolismo , Peroxidación de Lípido , Estrés Oxidativo , Petróleo/toxicidad
13.
J Antimicrob Chemother ; 77(3): 656-664, 2022 02 23.
Artículo en Inglés | MEDLINE | ID: mdl-34894246

RESUMEN

BACKGROUND: Gonorrhoea, caused by Neisseria gonorrhoeae, has spread worldwide. Strains resistant to most antibiotics, including ceftriaxone and azithromycin, have emerged to an alarming level. Rapid testing for N. gonorrhoeae and its antimicrobial resistance will therefore contribute to clinical decision making for early diagnosis and rational drug use. METHODS: A Cas13a-based assay (specific high-sensitivity enzymatic reporter unlocking; SHERLOCK) was developed for N. gonorrhoeae detection (porA gene) and azithromycin resistance identification (A2059G, C2611T). Assays were evaluated for sensitivity with purified dsDNA and specificity with 17 non-gonococcal strains. Performance of SHERLOCK (porA) was compared with Roche Cobas 4800 using 43 urine samples. Identification of azithromycin resistance mutations (A2059G, C2611T) was evaluated using a total of 84 clinical isolates and 18 urine samples. Lateral flow was tested for this assay as a readout tool. Moreover, we directly assayed 27 urethral swabs from patients with urethritis to evaluate their status in terms of N. gonorrhoeae infection and azithromycin resistance. RESULTS: The SHERLOCK assay was successfully developed with a sensitivity of 10 copies/reaction, except 100 copies/reaction for A2059G, and no cross-reaction with other species. Comparison of the SHERLOCK assay with the Cobas 4800 revealed 100% concordance within 18 positive and 25 negative urine samples. Of the 84 isolates, 21 strains with azithromycin resistance mutations were distinguished and further verified by sequencing and MIC determination. In addition, 62.96% (17/27) strains from swab samples were detected with no mutant strains confirmed by sequencing. CONCLUSIONS: The SHERLOCK assay for rapid N. gonorrhoeae detection combined with azithromycin resistance testing is a promising method for application in clinical practice.


Asunto(s)
Gonorrea , Neisseria gonorrhoeae , Azitromicina/farmacología , Farmacorresistencia Bacteriana/genética , Gonorrea/diagnóstico , Humanos , Pruebas de Sensibilidad Microbiana
14.
Environ Pollut ; 268(Pt A): 115309, 2021 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-33152631

RESUMEN

An experimentally induced three-dimensional petroleum seepage flume was used to investigate its migration in heterogeneous soil layers and a method for monitoring resistivity was adopted, under conditions of fluctuating water levels and rainfall. The corresponding mechanisms were then analyzed based on the resistivity characteristics and combined with three-dimensional inversion images. Finally, physical and chemical property analysis was conducted to verify the results of resistivity monitoring. The results demonstrated that: (1) In the process of natural oil leakage, the variation of soil resistivity presents a concave shape in the resistivity profile. Thus, oil migration exhibited the following patterns. At first, circular migration front was dominant in a vertical direction. Subsequently, after vertical migration was impeded, lateral migration was dominant. As the crude oil gradually accumulated, the migration front broke through the limitation of lithologic interface and continued vertically. (2) By comparing the two resistivity monitoring methods, namely the Wenner and Pole-pole methods, it was demonstrated that the inversion resistivity measured by Wenner method was closer to the true resistivity, and the resistivity variations were more distinguishable. (3) The resistivity inversion profile demonstrated that the low resistivity anomaly of the crude oil leakage area was related to the low water content of the soil layer in the test area. (4) Fluctuations in water level increased the diffusion range of crude oil beyond the original pollution source area, especially horizontally. (5) Percolation of rainfall caused the water level to rise, and the crude oil was evenly distributed in the soil layers above the capillary zone. (6) Through sample analysis and verification, it was demonstrated that the resistivity method can accurately and intuitively present the characteristics of crude oil migration. These results provide theoretical support for the rapid determination of the migration range and characteristics of crude oil in heterogeneous soil layers.


Asunto(s)
Petróleo , Contaminantes del Suelo , Difusión , Suelo , Contaminantes del Suelo/análisis , Agua
15.
Environ Sci Pollut Res Int ; 25(4): 3802-3812, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-29177997

RESUMEN

Oil spills frequently occur on both land and sea. Petroleum in mobile phase will cause serious pollution in the sediment and can form a secondary pollution source. Therefore, it is very important to study the migration of petroleum in sediments ideally in a rapid and simplified approach. The release of diesel was simulated using fine beach sand to construct a model aquifer, and dynamic monitoring was carried out using an automated monitoring system including a resistivity probe originally developed by our research group. The mobile phase migration fronts were determined accurately using wavelet analysis method combined with resistivity curve method. Then, a relationship between resistivity and the joint oil-water content was established. The main conclusions were as follows. The seepage velocity of the diesel with high mobility at the initial stage of infiltration was faster, followed by a period when gravity seepage was dominant, and finally a redistribution period at the later stage, which was mainly an oil-water displacement process. The resistivity trends for diesel infiltration in different water-saturated soil layers varied with depth. The resistivity in the vadose zone fluctuated significantly, increasing initially and later decreasing. The resistivity change in the capillary zone was relatively small and constant in the initial stage; then, it increased and subsequently decreased. The resistivity in the saturated zone was basically unchanged with depth, and the value became slightly larger than the background value over time. Overall, for a large volume of mobile phase diesel leakage, the arrival migration fronts can be detected by wavelet analysis combined with resistivity curves. The thickness of the oil slick in the capillary zone can be estimated by resistivity changes. The relationships between resistivity and both the moisture content and oil-water joint saturation are in agreement with the linear models. The research results provide basic data and a new data processing method for monitoring of contaminated sites following major oil spills using the resistivity method.


Asunto(s)
Gasolina/análisis , Modelos Teóricos , Contaminación por Petróleo/análisis , Dióxido de Silicio/química , Contaminantes del Suelo/análisis , Suelo/química , Movimientos del Agua
16.
Environ Monit Assess ; 188(4): 229, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26984566

RESUMEN

The aim of this study was risk characterization of a replaced urban industrial land located north of Qingdao, in relation to heavy metals values. Soil concentrations of Cd, Pb, Cu, Ni, Cr, and Zn were analyzed. It was observed that the components of Cd, Pb, Cu, Ni, Cr, and Zn are about 2.22, 8.07, 4.70, 6.81, 2.65, and 3.0-folds, respectively, when compared with the local natural background values in Qingdao. The spatial distribution of heavy metals indicated that these hotspots for Cr and Zn located in the southwestern part, Ni and Cd in the middle of the south area, Pb in the northwest, and Cu in the middle of the east area. The values of pollution index and Nemerow integrated pollution index revealed that 100 % of soil samples were moderately or heavily contaminated by six heavy metals. From these results, human health risk assessment for sensitive population was performed according to two different land uses. For non-carcinogenic risk, the direct oral ingestion appeared to be the main exposure pathway followed by dermal and inhalation absorption. The HI values of Pb and Cr characterized for children were larger than 1, while HI values of each metal for adults in two scenarios were lower than 1. Besides, carcinogenic risk from inhalation exposure to Cr for children and adults in two scenarios all exceeded the safety limit.


Asunto(s)
Exposición a Riesgos Ambientales/estadística & datos numéricos , Contaminación Ambiental/estadística & datos numéricos , Metales Pesados/análisis , Contaminantes del Suelo/análisis , Adulto , Niño , China , Humanos , Industrias , Medición de Riesgo , Suelo/química
17.
Huan Jing Ke Xue ; 34(9): 3663-8, 2013 Sep.
Artículo en Chino | MEDLINE | ID: mdl-24289020

RESUMEN

The determination of pollution extent and health risk assessment are the premise of heavy metal contaminated site remediation. The content of Cu, Cr, Pb, Cd, Zn, Ni in Qingdao North Station was detected, and the correlation of the 6 kinds of heavy metal content was analyzed. The pollution extent in excess of background values was characterized by anthropogenic influence multiple, and the pollution of heavy metal in soil was evaluated using geoaccumulation index and a new method which connects geoaccumulation index with Nemero index. Finally, human health risk assessment was carried out with health risk assessment model for heavy metal content. The results showed that Qingdao North Station soil were polluted by heavy metals. Six heavy metal pollution levels were: Cd > Cu > Ni > Pb > Cr > Zn, and Cd had reached the severity pollution level, Cu and Ni followed by, Cr, Pb and Zn were in minor pollution level. The order of coefficient variation in all heavy metals was: Cd > Ni > Cr > Zn > Pb > Cu. Within the study area soil heavy metal distribution was different, but overall discrepancy was small. The order of non-cancer hazards of heavy metals in soil was Cr > Pb > Cu > Ni > Cd > Zn, and the order of carcinogen risks of heavy metals was Ni > Cd. The non-cancer hazard and carcinogen risks values of metals were both lower than that their threshold values. They were not the direct threats to human health.


Asunto(s)
Monitoreo del Ambiente , Metales Pesados/análisis , Contaminantes del Suelo/análisis , China , Suelo/química
18.
Drug Chem Toxicol ; 33(3): 244-53, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20429794

RESUMEN

The antiviral drug combination consisting of arbidol and acetaminophen was investigated for its 4-week repeated oral administration in Sprague-Dawley rats. Groups of rats (10/sex in low-dose group, 15/sex in other three groups) were given at doses of 0, 200, 400, and 800 mg/kg/day. Clinical signs, mortality, body weight, food consumption, hematology, clinical biochemistry, macroscopic findings, organ weights, and histopathology were examined. The administration resulted in increased incidence of piloerection in most of the high-dose females and in some of the high-dose males and mid-dose females. Histopathological examinations revealed minor treatment-related change in the stomach of the high-dose animals. A decrease in body-weight gains and an increase in liver weight were observed in the mid- and high-dose groups. These treatment-related effects were reversible at the 2-week recovery period. A number of other clinical and pathological findings were not considered to be treatment related, since these changes occurred only in one sex were among the normal historical ranges, which were not supported by histopathological findings. Under the conditions of the present study, the no-observed-adverse-effect-level for 4-week oral administration to rats was considered 200 mg/kg/day, based on clinical observations, pathological findings, body-weight losses, and liver-weight changes.


Asunto(s)
Acetaminofén/toxicidad , Analgésicos no Narcóticos/toxicidad , Antivirales/toxicidad , Indoles/toxicidad , Acetaminofén/administración & dosificación , Administración Oral , Analgésicos no Narcóticos/administración & dosificación , Animales , Antivirales/administración & dosificación , Recuento de Células Sanguíneas , Análisis Químico de la Sangre , Peso Corporal/efectos de los fármacos , Esquema de Medicación , Combinación de Medicamentos , Ingestión de Alimentos/efectos de los fármacos , Femenino , Hematócrito , Hemoglobinas/análisis , Histocitoquímica , Indoles/administración & dosificación , Masculino , Distribución Aleatoria , Ratas , Ratas Sprague-Dawley
19.
Basic Clin Pharmacol Toxicol ; 104(2): 93-100, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19053993

RESUMEN

Magnesium fructose-1,6-diphosphate is a novel agent of antimyocardial ischaemia. In the present study, the subchronic toxicity of magnesium fructose-1,6-diphosphate was investigated after 13-week repeated intravenous administration in beagle dogs. The animals received doses of 0, 75, 150 and 300 mg/kg/day (three males and three females for each dose). During the study period, clinical signs, mortality, body weights, food consumption, electrocardiogram, urinalysis, haematology, clinical biochemistry, macroscopic findings, organ weights and histopathology were examined. The administration of magnesium fructose-1,6-diphosphate resulted in increased incidence of clinical signs, including salivation and emesis. These effects were transient and were noted in almost all dogs given 300 mg/kg/day and occasionally noted in the 150 mg/kg/day dose-treated animals. Serum magnesium in the 150 mg/kg/day and 300 mg/kg/day dose-treated animals was significantly increased after 6- and 13-week administration, but recovered at the end of a 2-week recovery period. At 6 weeks, a statistically significant decrease in serum electrolytes, including sodium and potassium, was observed in the treatment groups. There were no other treatment-related findings. Under the conditions of the present study, magnesium fructose-1,6-diphosphate did not show any evidence of target organ toxicity. The no-observed-adverse-effect level for 13-week intravenous administration of magnesium fructose-1,6-diphosphate to beagle dogs was considered 75 mg/kg/day based on observations of clinical signs and serum electrolytes.


Asunto(s)
Fármacos Cardiovasculares/toxicidad , Fructosadifosfatos/toxicidad , Magnesio/toxicidad , Animales , Fármacos Cardiovasculares/sangre , Fármacos Cardiovasculares/química , Perros , Relación Dosis-Respuesta a Droga , Femenino , Fructosadifosfatos/sangre , Fructosadifosfatos/química , Inyecciones Intravenosas , Dosificación Letal Mediana , Magnesio/sangre , Magnesio/química , Masculino , Dosis Máxima Tolerada , Pruebas de Toxicidad Crónica
20.
Reprod Biomed Online ; 6(3): 323-31, 2003.
Artículo en Inglés | MEDLINE | ID: mdl-12735868

RESUMEN

Controlling multiple pregnancies in patients undergoing artificial reproductive procedures requires consideration of single embryo transfers. Therefore, refinements for embryo evaluation are needed that select for the most developmentally competent embryo. The present study was designed to identify day 3 and day 5 morphological predictors of viability following transfers in which the morphology and fate of each embryo was precisely determined. Assessments on day 3 included cell number, and the extent of fragmentation and asymmetry, and on day 5, the developmental stage. Embryos resulting in a viable fetus at 11 weeks gestation were considered developmentally competent. The relationships among individual and collective embryo morphological characteristics were evaluated. Analysis of the interactions among morphological characteristics of embryos transferred on day 3 enabled identification of a multivariable selection order. Assessment of day 5 embryos revealed that expanding and expanded blastocysts exhibited comparable developmental potential that was superior to that of either morulae or early blastocysts. However, expanding or expanded blastocysts derived from 7-cell or 8-cell embryos were developmentally superior to those derived from other cleavage stages, regardless of fragmentation or asymmetry. Collectively, these findings further understanding of morphological predictors of viability, thereby improving the ability to select the most viable embryo for transfer.


Asunto(s)
Blastocisto , Transferencia de Embrión , Embrión de Mamíferos/fisiología , Fertilización In Vitro/métodos , Mórula , Adulto , Fragmentación del ADN , Embrión de Mamíferos/patología , Desarrollo Embrionario y Fetal , Femenino , Viabilidad Fetal , Humanos , Edad Materna , Oocitos/metabolismo , Embarazo , Embarazo de Alto Riesgo , Factores de Tiempo
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...