Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 34
Filtrar
Más filtros










Base de datos
Intervalo de año de publicación
1.
Huan Jing Ke Xue ; 44(9): 5253-5263, 2023 Sep 08.
Artículo en Chino | MEDLINE | ID: mdl-37699843

RESUMEN

To study the sources and potential risks of heavy metals in soils of characteristic agricultural product producing areas is of great significance for the scientific management and safe utilization of soil and crop resources. The contents of heavy metals As, Cd, Cr, Cu, Hg, Ni, Pb, and Zn in the 254 surface soil samples collected from the Heze oil peony planting area were determined. The content characteristics and correlation of heavy metals were analyzed using multivariate statistical methods. The sources of heavy metals in topsoil were analyzed using Igeo, PMF, and PCA/APCS. The ecological risks of the eight heavy metals were assessed through the potential ecological risk index (PERI). The results showed that the average contents of seven heavy metals in the soil were basically consistent with the background values of soil elements in Heze City, except that the average value of Cd was 1.44 times higher than the background value in Heze City. Correlation analysis and cluster analysis revealed that Pb, Hg, and Cd elements in the soil were greatly affected by human activities in the later period. The sources of eight heavy metals in the study area were natural sources, agricultural fertilizer sources, industrial coal sources, and domestic transportation sources, with the contribution rates of 81.31%, 15.45%, 2.74%, and 0.50%, respectively; 84.25% of the sites in the study area were at slight ecological risk, whereas the moderate risk and strong risk sites accounted for 14.96% and 0.79%, respectively. Among them, Cd and Hg were the dominant elements of ecological risk in the study area.

2.
Allergy ; 2023 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-37681299

RESUMEN

BACKGROUND: Neutrophil migration into the airways is a key process in neutrophilic asthma. Developmental endothelial locus-1 (DEL-1), an extracellular matrix protein, is a neutrophil adhesion inhibitor that attenuates neutrophilic inflammation. METHODS: Levels of DEL-1 were measured in exhaled breath condensate (EBC) and serum in asthma patients by ELISA. DEL-1 modulation of neutrophil adhesion and transepithelial migration was examined in a co-culture model in vitro. The effects of DEL-1-adenoviral vector-mediated overexpression on ovalbumin/lipopolysaccharide (OVA/LPS)-induced neutrophilic asthma were studied in mice in vivo. RESULTS: DEL-1 was primarily expressed in human bronchial epithelial cells and was decreased in asthma patients. Serum DEL-1 concentrations were reduced in patients with severe asthma compared with normal subjects (567.1 ± 75.3 vs. 276.8 ± 29.36 pg/mL, p < .001) and were negatively correlated to blood neutrophils (r = -0.2881, p = .0384) and neutrophil-to-lymphocyte ratio (NLR) (r = -0.5469, p < .0001). DEL-1 concentrations in the EBC of severe asthmatic patients (113.2 ± 8.09 pg/mL) were also lower than normal subjects (193.0 ± 7.61 pg/mL, p < .001) and were positively correlated with the asthma control test (ACT) score (r = 0.3678, p = .0035) and negatively related to EBC IL-17 (r = -0.3756, p = .0131), myeloperoxidase (MPO) (r = -0.5967, p = .0055), and neutrophil elastase (NE) (r = -0.5488, p = .0009) expression in asthma patients. Neutrophil adhesion and transepithelial migration in asthma patients were associated with LFA-1 binding to ICAM-1 and inhibited by DEL-1. DEL-1 mRNA and protein expression in human bronchial epithelial cells were regulated by IL-17. Exogenous DEL-1 inhibited IL-17-enhanced neutrophil adhesion and migration. DEL-1 expression was decreased while neutrophil infiltration was increased in the airway of a murine model of neutrophilic asthma. This was prevented by DEL-1 overexpression. CONCLUSIONS: DEL-1 down-regulation leads to increased neutrophil migration across bronchial epithelial cells and is associated with neutrophilic airway inflammation in asthma.

3.
Anal Chem ; 95(20): 8113-8120, 2023 05 23.
Artículo en Inglés | MEDLINE | ID: mdl-37162406

RESUMEN

Identification of a drug mechanism is vital for drug development. However, it often resorts to the expensive and cumbersome omics methods along with complex data analysis. Herein, we developed a methodology to analyze organelle staining images of single cells using a deep learning algorithm (TL-ResNet50) for rapid and accurate identification of different drug mechanisms. Based on the organelle-related cell morphological changes caused by drug action, the constructed deep learning model can fast predict the drug mechanism with a high accuracy of 92%. Further analysis reveals that drug combination at different ratios can enhance a certain mechanism or generate a new mechanism. This work would highly facilitate clinical medication and drug screening.


Asunto(s)
Aprendizaje Profundo , Fluorescencia , Algoritmos , Fenotipo
4.
Allergy ; 78(6): 1507-1523, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37026502

RESUMEN

BACKGROUND: Allergen source-derived proteases are a critical factor in the formation and development of asthma. The cysteine protease activity of house dust mite (HDM) disrupts the epithelial barrier function. The expression of cystatin SN (CST1) is elevated in asthma epithelium. CST1 inhibits the cysteine protease activity. We aimed to elucidate the role of epithelium-derived CST1 in the development of asthma caused by HDM. METHODS: CST1 protein levels in sputum supernatants and serum of patients with asthma and healthy volunteers were measured by ELISA. The ability of CST1 protein to suppress HDM-induced bronchial epithelial barrier function was examined in vitro. The effects of exogenous CST1 protein on abrogating HDM-induced epithelial barrier function and inflammation were examined in mice in vivo. RESULTS: CST1 protein levels were higher in sputum supernatants (142.4 ± 8.95 vs 38.87 ± 6.85 ng/mL, P < 0.0001) and serum (1129 ± 73.82 vs 703.1 ± 57.02 pg/mL, P = 0.0035) in patients with asthma than in healthy subjects. The levels were significantly higher in patients with not well- and very poorly controlled asthma than those with well-controlled asthma. Sputum and serum CST1 protein levels were negatively correlated with lung function in asthma. CST1 protein levels were significantly lower in the serum of HDM-specific IgE (sIgE)-positive asthmatics than in sIgE-negative asthmatics. The HDM-induced epithelial barrier function disruption was suppressed by recombinant human CST1 protein (rhCST1) in vitro and in vivo. CONCLUSION: Our data indicated that human CST1 protein suppresses asthma symptoms by protecting the asthmatic bronchial epithelial barrier through inhibiting allergenic protease activity. CST1 protein may serve as a potential biomarker for asthma control.


Asunto(s)
Asma , Proteasas de Cisteína , Humanos , Ratones , Animales , Pyroglyphidae , Cistatinas Salivales , Asma/etiología , Dermatophagoides pteronyssinus , Alérgenos , Epitelio , Péptido Hidrolasas , Antígenos Dermatofagoides , Polvo
5.
Parasitol Res ; 122(5): 1107-1126, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36933066

RESUMEN

The identification of additional Echinococcus granulosus sensu lato (s.l.) complex species/genotypes in recent years raises the possibility that there might be more variation among this species in China than is currently understood. The aim of this study was to explore intra- and inter-species variation and population structure of Echinococcus species isolated from sheep in three areas of Western China. Of the isolates, 317, 322, and 326 were successfully amplified and sequenced for cox1, nad1, and nad5 genes, respectively. BLAST analysis revealed that the majority of the isolates were E. granulosus s.s., and using the cox1, nad1, and nad5 genes, respectively, 17, 14, and 11 isolates corresponded to Elodea canadensis (genotype G6/G7). In the three study areas, G1 genotypes were the most prevalent. There were 233 mutation sites along with 129 parsimony informative sites. A transition/transversion ratio of 7.5, 8, and 3.25, respectively, for cox1, nad1, and nad5 genes was obtained. Every mitochondrial gene had intraspecific variations, which were represented in a star-like network with a major haplotype with observable mutations from other distant and minor haplotypes. The Tajima's D value was significantly negative in all populations, indicating a substantial divergence from neutrality and supporting the demographic expansion of E. granulosus s.s. in the study areas. The phylogeny inferred by the maximum likelihood (ML) method using nucleotide sequences of cox1-nad1-nad5 further confirmed their identity. The nodes assigned to the G1, G3, and G6 clades as well as the reference sequences utilized had maximal posterior probability values (1.00). In conclusion, our study confirms the existence of a significant major haplotype of E. granulosus s.s. where G1 is the predominant genotype causing of CE in both livestock and humans in China.


Asunto(s)
Equinococosis , Echinococcus granulosus , Animales , Humanos , Ovinos , Echinococcus granulosus/genética , Tibet , Equinococosis/epidemiología , Equinococosis/veterinaria , China , Genotipo , Haplotipos , Mutación , Filogenia , Variación Genética
6.
Int J Biol Macromol ; 229: 1036-1043, 2023 Feb 28.
Artículo en Inglés | MEDLINE | ID: mdl-36603727

RESUMEN

Ammonia and nitrite are nitrogenous pollutants in aquaculture effluents, which pose a major threat to the health of aquatic animals. In this study, we developed a nitrogen conversion strategy based on synthesis of poly-γ-glutamic acid (γ-PGA) by Bacillus subtilis NX-2. The nitrogen removal efficiency of NX-2 was closely related to synthesizing γ-PGA, and was positively correlated with the inoculum level. The degradation rates of ammonia nitrogen and nitrite at 104 CFU/mL were 84.42 % and 62.56 %, respectively. Through adaptive laboratory evolution (ALE) experiment, we obtained a strain named ALE 5 M with ammonia degradation rate of 98.03 % and nitrite of 93.62 % at the inoculum level of 104 CFU/mL. Transcriptome analysis showed that the strain was more likely to produce γ-PGA after ALE. By enzyme activity and qPCR analysis, we confirmed that ALE 5 M degraded ammonia nitrogen through γ-PGA synthesis, which provided a new way for nitrogen removal in aquaculture water.


Asunto(s)
Amoníaco , Ácido Glutámico , Ácido Glutámico/metabolismo , Amoníaco/metabolismo , Nitrógeno/metabolismo , Nitritos/metabolismo , Bacillus subtilis/metabolismo , Ácido Poliglutámico/metabolismo , Acuicultura
7.
Front Psychol ; 13: 947012, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36110278

RESUMEN

With the assistance of the corpus analysis tool Wmatrix 4.0, this paper analyzes the semantic categories of the top 10 commercial banks of China and the United States to figure out their social-cultural behavior in the Internet business context. It is discovered that both common and distinctive identities were constructed: the common identities include the professional financial service provider, responsible corporation for employees, and relevant communities with environmental and social consciousness, while the distinctive identities are manifested in the communication strategy, style, and persuasion mode: (1) The Chinese Commercial Banks adopted the proactive strategy for corporate identity construction, are prone to take hierarchical and impersonal communication style, and more focused on the "credibility appeal" and "rational appeal" in persuasion mode; (2) the commercial banks of the United States are more reactive in the communication strategy, position themselves in short distance with the putative audience in communication style, and conform to the typical "affective appeal" regarding the persuasion mode. From the intercultural perspective, the distinctions are the representation of the peculiar high-context culture and low-context culture based on Hofstede's cultural dimensions theory. Chinese banks should try to shorten the cultural gap by adopting communication strategy in conformity with the local cultural when going global rather than sticking to the domestic communication strategy.

8.
Materials (Basel) ; 15(15)2022 Jul 29.
Artículo en Inglés | MEDLINE | ID: mdl-35955190

RESUMEN

The microstructure evolution and plastic deformation mechanism of a Ta-2.5W liner under the ultra-high-strain-rate conditions generated by the explosive detonation were investigated in this study. For this purpose, a modular soft-recovery apparatus was designed to non-destructively recover the Ta-2.5W explosively formed projectile (EFP) in the ballistic endpoint. The electron backscattered diffraction (EBSD) method was employed to examine the microstructure of the Ta-2.5W liner before and after deformation. The microstructure of the recovered EFP exhibited significant grain refinement with preferred fiber texture. The theoretical computation results showed that the temperature of the EFP was in the range of 0.27-0.65 Tm. The deformation mechanism of the Ta-2.5W liner forming EFP driven by the detonation is the continuous dynamic recrystallization (CDRX) induced by high strain deformation, rather than the conventional dynamic recrystallization of nucleation and growth. The new grain structures evolve when the low-angle grain boundaries are transformed into the high-angle grain boundaries, and the specific grain refinement mechanism is the progressive rotation of subgrains near pre-existing grain boundaries.

9.
Front Immunol ; 13: 869050, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35450076

RESUMEN

Ischemia-reperfusion injury (IRI) is a common complication associated with liver surgery, and macrophages play an important role in hepatic IRI. Liraglutide, a glucagon-like peptide-1 (GLP-1) analog primarily used to treat type 2 diabetes and obesity, regulates intracellular calcium homeostasis and protects the cardiomyocytes from injury; however, its role in hepatic IRI is not yet fully understood. This study aimed to investigate whether liraglutide can protect the liver from IRI and determine the possible underlying mechanisms. Our results showed that liraglutide pretreatment significantly alleviated the liver damage caused by ischemia-reperfusion (I/R), as evidenced by H&E staining, serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels, and TUNEL staining. Furthermore, the levels of inflammatory cytokines elicited by I/R were distinctly suppressed by liraglutide pretreatment, accompanied by significant reduction in TNF-α, IL-1ß, and IL-6 levels. Furthermore, pretreatment with liraglutide markedly inhibited macrophage type I (M1) polarization during hepatic IRI, as revealed by the significant reduction in CD68+ levels in Kupffer cells (KCs) detected via flow cytometry. However, the protective effects of liraglutide on hepatic IRI were partly diminished in GLP-1 receptor-knockout (GLP-1R-/-) mice. Furthermore, in an in vitro study, we assessed the role of liraglutide in macrophage polarization by examining the expression profiles of M1 in bone marrow-derived macrophages (BMDMs) from GLP-1R-/- and C57BL/6J mice. Consistent with the results of the in vivo study, liraglutide treatment attenuated the LPS-induced M1 polarization and reduced the expression of M1 markers. However, the inhibitory effect of liraglutide on LPS-induced M1 polarization was largely abolished in BMDMs from GLP-1R-/- mice. Collectively, our study indicates that liraglutide can ameliorate hepatic IRI by inhibiting macrophage polarization towards an inflammatory phenotype via GLP-1R. Its protective effect against liver IRI suggests that liraglutide may serve as a potential drug for the clinical treatment of liver IRI.


Asunto(s)
Diabetes Mellitus Tipo 2 , Daño por Reperfusión , Animales , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Lipopolisacáridos/farmacología , Liraglutida/farmacología , Liraglutida/uso terapéutico , Hígado/metabolismo , Macrófagos/metabolismo , Ratones , Ratones Endogámicos C57BL , Daño por Reperfusión/metabolismo
10.
Sci Total Environ ; 805: 150260, 2022 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-34537698

RESUMEN

The performance of a permeable reactive barrier (PRB) for the in situ remediation of hexavalent chromium [Cr(VI)] contaminated groundwater, and the resulted responses in the indigenous microbial community, were investigated in a field-scale study. The PRB consisted of a mixture of zero-valent iron (ZVI), gravel and sand. The results showed that the PRB segment with 20% active reaction medium (ZVI) was able to successfully reduce Cr(VI) via chemical reduction from 27.29-242.65 mg/L to below the clean-up goal of 0.1 mg/L, and can be scaled-up under field conditions. It was found that the ZVI induced significant changes in the indigenous microbial community structure and compositions in the area of the PRB and those areas downgradient. The competitive growth among Cr(VI)-reducing bacteria (the reduced abundance of Hydrogenophaga, Pseudomonas, Exiguobacterium and Rhodobacter, along with the enrichment of Rivibacter and Candidatus_Desulforudis) were observed in PRB. In addition, Cr(VI)-reducing bacteria (Hydrogenophaga, Pseudomonas, Exiguobacterium and Rhodobacter) were enriched in the downgradient of PRB, indicating that Cr(VI) can be further bio-reduced to Cr(III). The Cr(VI) bio-reduction could serve as a secondary mechanism for further removal of Cr(VI) from contaminated groundwater, suggesting that the actual lifetime of a PRB can be prolonged, which is important for the design and economic assessment of a PRB. Further analysis revealed that pH, dissolved oxygen, Cr(VI) level, the oxidation-reduction potential, and temperature were the main environmental factors influencing the subsurface microbial community compositions.


Asunto(s)
Restauración y Remediación Ambiental , Agua Subterránea , Microbiota , Contaminantes Químicos del Agua , Cromo/análisis , Hierro , Contaminantes Químicos del Agua/análisis
11.
Environ Sci Pollut Res Int ; 28(32): 44389-44407, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33847886

RESUMEN

In this paper, three bioretention facilities (BT, RG1-A, and RG1-B) were selected for on-site testing and experimental analysis. Of which, BT is a roadside bioretention tank with layered filler, while RG1-A and RG1-B are rain gardens with conventional filler (Bioretention soil media, BSM) and modified filler (BSM+10% Water treatment residuals,WTR), respectively. The effect of pollutant accumulation on the soil microbial community structure in the facilities, and the risk of heavy metal contamination over several years of bioretention facility operation were studied. Results showed that the water quality pollutant load reduction in BT was fluctuating. This is related  to the poor water quality of road stormwater flowing into BT and the facility filler. Because RG1-B uses modified filler, RG1-B was more effective than RG1-A in regulating water quality and quantity; the changes in soil physical and chemical properties in BT, RG1-A, and RG1-B were influenced by external factors. Next, BT was at high risk of heavy metal contamination than other facilities. The microbial community structure of the facility had the following characteristics: at the phylum level, Proteobacteria was the dominant phylum in the bioretention facility, accounting for 29-45%; and at the genus level, Blastocatella was the dominant phylum, and the relative abundance in situ was higher than that in the bioretention facility. The results of the correlation analysis combining filler environmental factors and microbial community structure indicated that SMC was a highly influential factor among the three facilities.


Asunto(s)
Contaminantes Ambientales , Microbiota , Purificación del Agua , Lluvia , Suelo
12.
Sci Total Environ ; 772: 145495, 2021 Jun 10.
Artículo en Inglés | MEDLINE | ID: mdl-33770851

RESUMEN

A large gap exists between laboratory findings and successful implementation of bioremediation technologies for the treatment of chromium (Cr)-contaminated sites. This work conducted the enhanced bioremediation of Cr(VI) in situ via the addition of organic carbon (ethanol) coupled with a dynamic groundwater recirculation (DGR)-based system in a field-scale study. The DGR system was applied to successfully (1) remove Cr(VI) from groundwater via enhanced flushing by the recirculation system and (2) deliver the biostimulant to the heterogeneous subsurface environment, including a sand/cobble aquifer and a fractured bedrock aquifer. The results showed that the combined extraction and bioreduction of Cr(VI) were able to reduce Cr(VI) concentrations from 1000 to 2000 mg/L to below the clean-up goal of 0.1 mg/L within the operation period of 52 days. The effectiveness of Cr(VI) bioremediation and the relationship between microbial communities and geochemical parameters were evaluated. Multiple-line of evidence demonstrated that the introduction of ethanol significantly stimulated a variety of bacteria, including those responsible for denitrification, sulfate reduction and reduction of Cr(VI), which contributed to the establishment of reducing conditions in both aquifers. Cr(VI) was removed from groundwater via combined mechanisms of physical removal through the DGR system and the bioreduction of Cr(VI) followed by precipitation. In particular, it was found competitive growth among Cr(VI)-reducing bacteria (such as the enrichment of Geobacter, along with the reduced relative abundance of Acinetobacter and Pseudomonas) was induced by ethanol injection. Furthermore, Cr(VI), total organic carbon, NO2-, and SO42- played important roles in shaping the composition of the microbial community and its functions.


Asunto(s)
Agua Subterránea , Biodegradación Ambiental , Cromo/análisis , Oxidación-Reducción
13.
PLoS One ; 15(11): e0241896, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33147282

RESUMEN

A cluster of patients with coronavirus disease 2019 (COVID-19) underwent repeated positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA tests after they were discharged from the hospital. We referred to them as re-positive (RP) patients in this study. We aimed to describe the clinical characteristics of these patients in a retrospective cohort study. After being treated for COVID-19, the patients underwent 14 days of quarantine following their discharge from the Huangshi Hospital of Traditional Chinese Medicine and the Huangshi Hospital of Youse. Two additional sequential SARS-CoV-2 RNA tests were performed at the end of quarantine. The median age of the 368 patients was 51 years, and 184 (50%) patients were female. A total of 23 RP patients were observed at follow-up. Using multivariate Cox regression analysis, risk factors associated with RP included a higher ratio of lymphocyte/white blood cell on admission (adjusted HR 7.038; 95% CI, 1.911-25.932; P = 0.0034), lower peak temperature during hospitalization (adjusted HR, 0.203; 95% CI, 0.093-0.443; P<0.0001), and the presence of comorbidities, particularly hypertension or chronic diseases in the respiratory system (adjusted HR, 3.883; 95% CI, 1.468-10.273; P = 0.0063). Antivirus treatment with arbidol was associated with a lower likelihood of re-positive outcomes (adjusted HR, 0.178; 95% CI, 0.045-0.709; P = 0.0144).


Asunto(s)
Betacoronavirus/genética , Infecciones por Coronavirus/diagnóstico , Infecciones por Coronavirus/virología , Neumonía Viral/diagnóstico , Neumonía Viral/virología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , COVID-19 , China , Comorbilidad , Femenino , Hospitalización , Humanos , Masculino , Persona de Mediana Edad , Pandemias , Alta del Paciente , Cuarentena , ARN Viral/genética , Estudios Retrospectivos , Factores de Riesgo , SARS-CoV-2 , Adulto Joven
14.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 28(5): 1668-1673, 2020 Oct.
Artículo en Chino | MEDLINE | ID: mdl-33067971

RESUMEN

OBJECTIVE: To investigate the difference of clinical characteristics between young patients(age≤40 years old) and middle-older patients(age>40 years old) with the myeloproliferative neoplasms(MPN). METHODS: The clinical data (gene mutations, peripheral blood routine examinations, imaging examination and past history) of 269 MPN patients was collected and analyzed. RESULTS: In essential thrombocythemia (ET) group, the proportion of triple-negative type in young patients was higher than that in middle-older group, while the peripheral white blood cell(WBC) and platelets(PLT) counts in the first visit were lower. In polycythemia vera (PV) group, the total detection rate of JAK2V617F (80.65%) was lower than that of other research reports. Young patients with PV showed the lower JAK2V617F rate and lower WBC count, compared with the middle-older aged patients. Both CALR and MPL mutations were not found in PV patients. There was only 1 primary myelofibrosis (PMF) patient aged <40 years old. 91.67% of the patients merged splenomegaly and this rate was higher than that of ET or PV patients. It was found that there were a diagnosed familial MPN family and an undiagnosed family, and the youngest patient was only 8 years old. The second-generation gene sequencing detection for them was not carried out. CONCLUSION: Age is an important reference index in the assessment of risks. The MPN patients with different age and types show much difference in gene mutations, peripheral blood cell counts, thrombotic events and sizes of spleen. The onset ages of patients with familial MPN trends to be generational younger.


Asunto(s)
Trastornos Mieloproliferativos , Policitemia Vera , Trombocitemia Esencial , Adulto , Anciano , Niño , Cromosomas , Humanos , Janus Quinasa 2/genética , Persona de Mediana Edad , Trastornos Mieloproliferativos/genética , Policitemia Vera/genética , Trombocitemia Esencial/genética
15.
Environ Pollut ; 245: 9-19, 2019 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-30408764

RESUMEN

Efficient injection and distribution of nanoparticles in porous media are considered a formidable technical hurdle for injection-based in situ remediation. One approach to enhance the mobility of nanoparticles in an aquifer is to use surface modifiers. In this study, nanoscale magnesia (NMgOs), an innovative and effective remedial material for cadmium (Cd) removal from groundwater, was modified with the negatively charged and eco-friendly humic acid to enhance its mobility in aquifers. A two-dimensional reactor (60 × 50 × 10 cm), with 2 injection wells and 30 monitoring wells was designed, constructed, and sand-packed in the laboratory to simulate a saturated aquifer. The simulated aquifer was pre-contaminated with Cd to simulate a plume in groundwater. The distribution of injected unmodified NMgOs and humic acid-modified NMgOs slurry were evaluated in the reactor. The radius of influence (ROI) of humic acid-modified NMgOs was estimated to be approximately 5 cm based on visual observation, while no ROI was apparent for the unmodified NMgOs because of their aggregation at the bottom of the injection wells. The concentrations of Cd and magnesium (Mg) were monitored in all 30 monitoring wells at different time intervals to evaluate the effectiveness of Cd removal. The breakthrough curve analysis revealed that humic acid enhances the transport of NMgOs in the saturated porous media. Furthermore, the results of scanning electron microscopy-energy dispersive x-ray (SEM-EDX) characterization of silica sand before and after injection of NMgOs verified the presence of 5.78% of Mg from humic acid-modified NMgOs and 0.19% from unmodified NMgOs at 35 cm downgradient of the injection wells, which are consistent with the conclusion drawn from the breakthrough curves.


Asunto(s)
Cadmio/aislamiento & purificación , Agua Subterránea/química , Sustancias Húmicas , Óxido de Magnesio/química , Nanopartículas , Contaminantes del Agua/aislamiento & purificación , Dióxido de Silicio , Pozos de Agua
16.
Anal Bioanal Chem ; 411(19): 4569-4576, 2019 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-30327835

RESUMEN

A simple fluorescence biosensor is developed based on the enzyme-assisted cascade amplification strategy. The amplification system consists of a hairpin-structure DNA (H-DNA) and exonuclease III. The target DNA can hybridize with the H-DNA and initiate exonuclease III-assisted target recycling amplification to generate abundant G-rich DNA (G-DNA). One region of G-DNA is designed to possess the same sequence as target DNA. Thus, the G-DNA can also hybridize with H-DNA and initiate the digestion of H-DNA. The cascade strategy in this amplification system causes the concentration of G-DNA to grow exponentially. The fluorescence intensity of N-methylmesoporphyrin IX (NMM) is highly enhanced due to the formation of G-quadruplex configuration. Under optimal conditions, the cascade system could achieve an admirable sensitivity with a detection limit of 52 fM for HIV DNA, and guarantees a satisfactory specificity. Moreover, the cascade system could be implemented for other target DNA detections by substituting the recognition region of the H-DNA. In this way, a detection limit of 65 fM for HBV DNA could be achieved by the cascade system. The target DNA analysis in a real serum sample further indicates that this biosensor has potential for future application in clinical diagnosis. Graphical abstract A simple and label-free cascade amplification strategy is developed by exploiting hairpin DNA and EXO III for sensitive DNA detection.


Asunto(s)
ADN/análisis , Técnicas Biosensibles , Exodesoxirribonucleasas/química , Fluorescencia , Límite de Detección , Mesoporfirinas/química , Técnicas de Amplificación de Ácido Nucleico
17.
Talanta ; 188: 685-690, 2018 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-30029432

RESUMEN

Taking advantage of the homogeneous and heterogeneous electrochemical biosensors, a simple, sensitive, and selective electrochemical biosensor is constructed by combining entropy-driven amplification (EDA) with DNA walker. This electrochemical biosensor realizes the biorecognition and EDA operation in homogeneous solution, which is beneficial to improve the recognition and amplification efficiency. A two-leg DNA walker generated by EDA can walk on the surface of gold electrode for cleaving the immobilized substrate DNA and releasing the electroactive labels, giving rise to a significant decrease of the electrochemical signal. The immobilization of the electroactive labels ensures the reproducibility and reliability of the biosensor. The present cascade amplification assay can be applied to detect target DNA with a detection limit of 0.29 fM, and base mutations can be easily distinguished. Moreover, the proposed electrochemical biosensor shows a satisfactory performance for the detection of target DNA in human serum. Thus, the novel electrochemical biosensor holds promising potential for a future application in disease diagnosis.


Asunto(s)
Técnicas Biosensibles/métodos , ADN Catalítico/química , ADN/sangre , Técnicas Electroquímicas/métodos , Ácidos Nucleicos Inmovilizados/sangre , Nanoestructuras/química , ADN/metabolismo , Electrodos , Oro/química , Humanos , Plomo/química , Límite de Detección , Azul de Metileno/química , Técnicas de Amplificación de Ácido Nucleico/métodos , Hibridación de Ácido Nucleico , Reproducibilidad de los Resultados
18.
Biosens Bioelectron ; 105: 159-165, 2018 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-29412940

RESUMEN

DNA can be modified to function as a scaffold for the construction of a DNA nanomachine, which can then be used in analytical applications if the DNA nanomachine can be triggered by the presence of a diagnostic DNA or some other analyte. We herein propose a novel and powerful DNA nanomachine that can detect DNA via combining the tandem strand displacement reactions and a DNA walker. Three different DNA sensing platforms are described, where the whole DNA machine was constructed on a gold electrode (GE). This cascade multiple amplification strategy exhibited an excellent sensitivity. Under optimal conditions, the electrochemical sensor could achieve a detection limit of 36 fM with a linear range from 50 to 500 fM. In particular, the electrochemical sensor could easily distinguish the base mutations. More interestingly, the DNA nanomachine could be used to construct analog AND and OR logic gates. We demonstrate that electrochemical signals generated from the different input combinations can be used to distinguish multiple target DNAs. The practical applicability of the present biosensor is demonstrated by the detection of target DNA in human serum with satisfactory results, which holds great potential for a future application in clinical diagnosis.


Asunto(s)
Técnicas Biosensibles/métodos , ADN/análisis , Disparidad de Par Base , ADN/sangre , ADN/genética , Técnicas Electroquímicas/métodos , Humanos , Límite de Detección , Técnicas de Amplificación de Ácido Nucleico/métodos
19.
Exp Ther Med ; 13(6): 2917-2921, 2017 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-28587360

RESUMEN

The value of Sonoclot detection technology to guide the clinical medication of the perioperative anticoagulation and antiplatelet therapy in patients with acute myocardial infarction (AMI) undergoing emergent percutaneous coronary intervention (PCI) was estimated. One hundred and twenty-eight patients were randomly divided into control group and observation group with 64 cases in each group. Control group adopted routine blood coagulation indexes, including prothrombin time, activated partial thromboplastin time, fibrinogen and plasma thrombin time, platelet count and platelet aggregation turbidity analysis; observation group adopted Sonoclot detection technology, including activated clotting time, coagulation rate and platelet function. Anticoagulant therapy selected was of low molecular weight heparin calcium perioperatively, intraoperative unfractionated heparin, and clopidogrel (75 mg) combined with aspirin enteric-coated tablets (100 mg) as antiplatelet drugs. The therapy was administered in accordance with blood coagulation results. The blood coagulation time, postoperative creatine kinase isoenzyme MB, cardiac troponin I and B-type natriuretic peptide levels in the observation group are significantly lower than those in the control group (P<0.05) though the operating time and specifications of the stenting did not show any significant difference (P>0.05). The incidence of recurrent myocardial infarction, microembolism, acute and subacute thrombosis and bleeding events in the observation group are significantly lower than those in the control group (P<0.05). In the control group, there is no difference in the coagulation indexes of the patients with thrombosis events or bleeding events or no event (P>0.05). Whereas, in the observation group, there is significant difference in coagulation indexes of the patients with thrombosis events or bleeding events or no event (P<0.05). In conclusion, Sonoclot detection technology instructs emergent PCI treatment in AMI patients to shorten the detection time of blood coagulation, reduce the degree of myocardial injury, reduce the incidence of perioperative thrombosis and bleeding events. Furthermore, it has great value in guiding the clinical medication of anticoagulation and antiplatelet therapy.

20.
Talanta ; 166: 87-92, 2017 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-28213264

RESUMEN

Simple, rapid, sensitive, and specific detection of cancer cells plays a pivotal role in the diagnosis and prognosis of cancer. A sandwich electrochemical biosensor was developed based on polyadenine (polydA)-aptamer modified gold electrode (GE) and polydA-aptamer functionalized gold nanoparticles/graphene oxide (AuNPs/GO) hybrid for the label-free and selective detection of breast cancer cells (MCF-7) via a differential pulse voltammetry (DPV) technique. Due to the intrinsic affinity between multiple consecutive adenines of polydA sequences and gold, polydA modified aptamer instead of thiol terminated aptamer was immobilized on the surface of GE and AuNPs/GO. The label-free MCF-7 cells could be recognized by polydA-aptamer and self-assembled onto the surface of GE. The polydA-aptamer functionalized AuNPs/GO hybrid could further bind to MCF-7 cells to form a sandwich sensing system. Characterization of the surface modified GE was carried out by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) using Fe(CN)63-/4- as a redox probe. Under the optimized experimental conditions, a detection limit of 8 cellsmL-1 (3σ/slope) was obtained for MCF-7 cells by the present electrochemical biosensor, along with a linear range of 10-105 cellsmL-1. By virtue of excellent sensitivity, specificity and repeatability, the present electrochemical biosensor provides a potential application in point-of-care cancer diagnosis.


Asunto(s)
Aptámeros de Nucleótidos/química , Técnicas Biosensibles/métodos , Neoplasias de la Mama/diagnóstico , Separación Celular/métodos , Poli A/química , Técnicas Biosensibles/instrumentación , Separación Celular/instrumentación , Electroquímica , Electrodos , Oro/química , Grafito/química , Humanos , Límite de Detección , Nanopartículas del Metal/química , Óxidos/química
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...