Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
1.
Aust N Z J Psychiatry ; 56(3): 292-300, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33985351

RESUMO

OBJECTIVE: Cognitive impairment is prevalent in schizophrenia. Macrophage migration inhibitory factor which is released into the circulation under stress or inflammation, is associated with cognition and also plays an important role in immunity. However, no study has investigated the relationship between macrophage migration inhibitory factor and cognitive function in first-episode schizophrenia patients at baseline or after treatment. This study investigated the pre- and post-risperidone treatment correlations between serum macrophage migration inhibitory factor levels and cognitive function in first-episode schizophrenia patients. METHODS: A total of 83 first-episode schizophrenia patients who received risperidone monotherapy and 57 healthy controls - matched for sex, age, smoking status, education (years), marital status and waist-to-hip ratio - were included. Macrophage migration inhibitory factor levels were measured before and 10 weeks after treatment in the patient group and at baseline in the controls. Pre- and post-treatment cognitive functions in patients were assessed using the MATRICS Consensus Cognitive Battery. RESULTS: At baseline, macrophage migration inhibitory factor levels were significantly higher in first-episode schizophrenia patients than those in healthy controls (p < 0.01) and decreased in patients after 10 weeks of risperidone treatment compared with baseline (p < 0.05). The MATRICS Consensus Cognitive Battery total score and the sub-scores for the Trail Making Test, Symbol Coding, Letter Number Sequence, Maze and Brief Visuospatial Memory Test-Revised improved significantly after risperidone treatment. After controlling for age, sex, education, waist-to-hip ratio and smoking status, partial correlation analysis showed a positive correlation between baseline macrophage migration inhibitory factor levels and patients' baseline MATRICS Consensus Cognitive Battery verbal memory scores (r = 0.29, p = 0.01). Macrophage migration inhibitory factor changes correlated negatively with verbal memory changes (r = -0.26, p = 0.04). Multiple linear regression analysis identified a definite correlation between the changes in word memory test score and macrophage migration inhibitory factor level (ß = -0.09, p = 0.04). CONCLUSION: Macrophage migration inhibitory factor may be involved in the process of cognitive impairment in first-episode schizophrenia and repair mechanisms following risperidone treatment.


Assuntos
Transtornos Cognitivos , Disfunção Cognitiva , Fatores Inibidores da Migração de Macrófagos , Esquizofrenia , Biomarcadores , Cognição , Disfunção Cognitiva/etiologia , Humanos , Testes Neuropsicológicos , Esquizofrenia/complicações , Esquizofrenia/tratamento farmacológico
2.
Huan Jing Ke Xue ; 45(6): 3468-3479, 2024 Jun 08.
Artigo em Zh | MEDLINE | ID: mdl-38897767

RESUMO

Antibiotics are widely used in animal husbandry, planting, and aquaculture in agricultural industries. A large amount of the parent antibiotics used are released into the environment through discharge via feces and urine, posing potential risks to human health and ecosystems. It is thus very important to understand how antibiotics in the agricultural environment threaten the ecological environment and human health. Accordingly, risk assessment of antibiotics in the environment has become the research focus in recent years. The aim of this study was to review the risk assessment methods of antibiotics. The results showed that the ecological environment risk has mainly been assessed by the risk quotient (RQ). Predicted no-impact concentrations (PNECs) are an important indicator for ecological environment risk assessment, but a definite value is still controversial. The hazard quotient (HQ) is generally used to assess health risks. At present, it is necessary to clarify the selection of antibiotic exposure pathways and toxicological thresholds. However, neither of these two methods have currently considered either mixed pollution or the risk of antibiotic metabolites. Further analysis indicated that the ecological risks of antibiotics in the water environment and feces/manure/soil environment were widespread, which had an impact on both the soil and water environment. The types of antibiotics with high risk were different for various cultivated types. The factors including test species, testing conditions, calculation methods, and soil types all affected the detection of PNECs. Human health risk caused by dietary intake of antibiotics was minimal, but it cannot be ignored given the seafood consumption in coastal areas. Moreover, quinolones have both high ecological and human health risks in the agricultural environment. Based on the amount of antibiotics in agriculture and the residual concentration or toxicity of antibiotics in the related environment, this study proposed a priority-control list of antibiotics in the agricultural environment and summarized the main problems in the current antibiotic risk assessment. It will provide helpful support for the scientific optimization of antibiotic risk assessment and the effective control of antibiotics in agricultural environments.


Assuntos
Antibacterianos , Monitoramento Ambiental , Medição de Risco , Antibacterianos/análise , Antibacterianos/efeitos adversos , Agricultura , Produtos Agrícolas/crescimento & desenvolvimento , Poluentes do Solo/análise , Poluentes Ambientais/análise
3.
J Chromatogr Sci ; 62(5): 465-470, 2024 May 31.
Artigo em Inglês | MEDLINE | ID: mdl-38213303

RESUMO

Although Vibrio parahaemolyticus (V. parahaemolyticus) is a pathogen frequently found in seafood, there is a possibility of its presence in other foods, such as dairy products. The main virulence factors of V. parahaemolyticus are thermostable direct hemolysins (TDHs) which are lethal toxins, so it is necessary to establish qualitative and quantitative methods for determining TDHs. HPLC-ESI-TOF was employed to establish a method for identifying TDHs. The identification and quantification ions of TDHs were confirmed by HPLC-ESI-TOF. The method was developed for detecting TDHs in milk powder using HPLC-ESI-TOF in this paper, and limits of detection (were between 0.20 and 0.40 mg/kg, limits of quantitation were between 0.5 and 1.0 mg/kg and recoveries of all TDHs were between from 78% to 94% with relative standard deviation lower than 10%. This research will provide a reference for developing methods of HPLC-MS/MS to detect TDHs in food samples, which can provide a tool for the government to monitor TDHs contamination in foods.


Assuntos
Proteínas Hemolisinas , Limite de Detecção , Leite , Espectrometria de Massas por Ionização por Electrospray , Cromatografia Líquida de Alta Pressão/métodos , Leite/química , Leite/microbiologia , Animais , Espectrometria de Massas por Ionização por Electrospray/métodos , Proteínas Hemolisinas/análise , Proteínas Hemolisinas/química , Toxinas Bacterianas/análise , Toxinas Bacterianas/química , Reprodutibilidade dos Testes , Modelos Lineares , Espectrometria de Massas em Tandem/métodos , Pós/química , Contaminação de Alimentos/análise , Vibrio parahaemolyticus/química , Vibrio parahaemolyticus/isolamento & purificação
4.
Anal Chem ; 85(1): 273-7, 2013 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-23215038

RESUMO

A bovine serum albumin (BSA)-monolayer-based probe carrier platform is shown to improve the performance of a conventional thiolated single-stranded DNA probe self-assembled-monolayer-based electrochemical DNA hybridization biosensor. A detection limit of 0.5 fM can be obtained in a very reproducible manner (relative standard deviation <5%), along with high specificity. The performance of the biosensor can be attributed primarily to the enhanced spatial positioning range and accessibility of the probes on the BSA-based platform. Furthermore, the novel biosensor shows high resistance to nonspecific adsorption of nucleic acid and protein and can be directly employed in detection in biological fluids. These advantages give this simple developed methodology great promise for a wide range of nucleic acid testing.


Assuntos
Técnicas Biossensoriais , Sondas de DNA/química , DNA/análise , Técnicas Eletroquímicas , Soroalbumina Bovina/química , Animais , Bovinos , DNA de Cadeia Simples/química , Eletrodos , Ouro/química , Hibridização de Ácido Nucleico
5.
Environ Sci Pollut Res Int ; 30(50): 108694-108705, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37751004

RESUMO

Staphylococcal enterotoxins (SEs) secreted by Staphylococcus aureus (S. aureus) can cause foodborne disease, nausea, vomiting and diarrhea, and even death. Regulation of SE expression is related to accessory gene regulators (Agr). It is important to reveal which environmental factors influence regulation of SE expression to prevent SE food poisoning outbreak. Hence, natural environmental factors which may have an impact on SE expression were selected, such as temperature, food types, strains, and competing strains. Seven strains of S. aureus carrying different SE genes were collected from the Chinese Academy of Inspection and Quarantine (CAIQ) strain bank for study. Strains were cultured with different conditions. Temperature was 8 °C, 22 °C, and 30 °C. Food type was milk powder and nutrient broth. Competing strains were Vibrio parahaemolyticus (V. parahaemolyticus), Escherichia coli (E. coli), and Bacillus cereus (B. cereus). The expression culture solution was pretreated by centrifugation, then determined by using SDS-PAGE, and distinguished SEs apart from each other by HPLC-ESI-TOF. There are 168 samples collected from SE expression culture; the result of SDS-PAGE suggests 23 samples were positive for SEs, and the other 145 samples were negative for SEs. The result of HPLC-ESI-TOF suggests that SEs with similar molecular weight can be distinguished in terms of m/z. The most important factor contributing to regulate expression of SEs was estimated by logistic regressive analysis. The result shows that McFadden R2 is 0.213; p value is 0.000 (p < 0.05); this result illustrates that the model is valid and meaningful. Strains, food types, temperature, and competing strands can explain the 21% change in SE expression. Temperature (z = 3.029, p = 0.002 < 0.01), strains (z = - 3.132, p = 0.002 < 0.01), and food types (z = - 2.415, p = 0.016 < 0.05) have significant impact on SE expression, and the competing strains (z = 1.230, p = 0.219 > 0.05) have no impact on the SE expression. More important impact on SE expression was estimated by OR value; the result shows that strength of temperature influencing on SE expression is bigger than strains and food types in terms of values of OR, temperature (OR = 2.862), strains (OR = 0.641), and food types (OR = 0.561); consequently, temperature is a key factor for stimulating SE expression and had high expression at 30 °C. Therefore, food easily contaminated with S. aureus should be monitored intensively at early and late summer, when proper temperature for expressing SEs may result in S. aureus food poisoning prevalence.


Assuntos
Intoxicação Alimentar Estafilocócica , Infecções Estafilocócicas , Humanos , Enterotoxinas/análise , Staphylococcus aureus/genética , Escherichia coli , Intoxicação Alimentar Estafilocócica/epidemiologia , Microbiologia de Alimentos
6.
Front Immunol ; 14: 1089809, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36776858

RESUMO

Oxidative stress is an important pathogenic factor in ulcerative colitis (UC) and colitis-associated colorectal cancer (CAC), further impairing the entire colon. Intestinal epithelial cells (IECs) are crucial components of innate immunity and play an important role in maintaining intestinal barrier function. Recent studies have indicated that microRNA-222-3p (miR-222-3p) is increased in colon of UC and colorectal cancer (CRC) patients, and miR-222-3p is a crucial regulator of oxidative stress. However, whether miR-222-3p influences IEC oxidative stress in UC and CAC remains unknown. This study investigated the effect of miR-222-3p on the regulation of IEC oxidative stress in UC and CAC. An in vitro inflammation model was established in NCM460 colonic cells, mouse UC and CAC models were established in vivo, and IECs were isolated. The biological role and mechanism of miR-222-3p-mediated oxidative stress in UC and CAC were determined. We demonstrated that miR-222-3p expression was notably increased in dextran sulfate sodium (DSS)-induced NCM460 cells and IECs from UC and CAC mice. In vitro, these results showed that the downregulation of miR-222-3p reduced oxidative stress, caspase-3 activity, IL-1ß and TNF-α in DSS-induced NCM460 cells. We further identified BRG1 as the target gene of miR-222-3p, and downregulating miR-222-3p alleviated DSS-induced oxidative injury via promoting BRG1-mediated activation Nrf2/HO-1 signaling in NCM460 cells. The in vivo results demonstrated that inhibiting miR-222-3p in IECs significantly relieved oxidative stress and inflammation in the damaged colons of UC and CAC mice, as evidenced by decreases in ROS, MDA, IL-1ß and TNF-α levels and increases in GSH-Px levels. Our study further demonstrated that inhibiting miR-222-3p in IECs attenuated oxidative damage by targeting BRG1 to activate the Nrf2/HO-1 signaling. In summary, inhibiting miR-222-3p in IECs attenuates oxidative stress by targeting BRG1 to activate the Nrf2/HO-1 signaling, thereby reducing colonic inflammation and tumorigenesis.


Assuntos
Colite Ulcerativa , Neoplasias Associadas a Colite , MicroRNAs , Animais , Camundongos , Colite Ulcerativa/complicações , Colite Ulcerativa/genética , Colite Ulcerativa/metabolismo , Inflamação , MicroRNAs/metabolismo , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo , Transdução de Sinais , Fator de Necrose Tumoral alfa/metabolismo
7.
Huan Jing Ke Xue ; 42(10): 4942-4950, 2021 Oct 08.
Artigo em Zh | MEDLINE | ID: mdl-34581138

RESUMO

Antibiotic residues in farmland soils resulting from the application of livestock manure poses risks to the soil and water ecology associated with the spread of antibiotic resistance, thereby threatening environmental safety and human health. Here, a leaching experiment was carried out using soil(CK-T), pig manure(PM-T), cow manure(CM-T), and chicken manure(CHM-T) with the addition of tetracyclines(tetracycline, oxytetracycline, and chlortetracycline) and a control group(without antibiotics). The effects of different sources of manure on soil physical and chemical indicators and bacterial abundance under simulated leaching conditions were studied, while the migration of tetracyclines in the different treatments were also determined. The results showed that compared with the CHM-T and CM-T treatments, the tetracyclines in the PM-T treatment were more easily accumulated in the soil(residual amounts=0.90-6.91 mg·kg-1 compared to the other treatments=0.33-4.42 mg·kg-1). Compared with the surface soil(0-4 cm), higher concentrations of tetracyclines were detected at soil depths of 16-24 cm. Consistent with the residues of antibiotics, the concentrations of TN and NH4+-N in the soil with the PM-T treatment were increased by 0.044 g·kg-1 and 14.11 mg·kg-1, respectively, which were significantly higher than other treatments. The abundance of bacteria in the soil was reduced due to the bactericidal effect of antibiotics, by 39.66% in the PM-T treatment, which was significantly higher than in the other treatments(12.38%-35.26%). Compared with other treatments, the antibiotics in the CHM-T treatment were more easily leached from the soil, with 9.91 mg of antibiotics in the leachate, which was significantly higher than the other treatments(P<0.05). TN, NH4+-N, tetracycline, oxytetracycline, and chlortetracycline were the first principal component factors, accounting for 54.55% of the variation, and corresponding concentrations increased with soil depth. Based on these results, tetracyclines in pig manure tended to accumulate in soil and transfer vertically along with variations in the soil microbial community. For chicken manure, relatively high concentrations of tetracyclines were detected in the soil leachate, increasing the risk of water pollution.


Assuntos
Esterco , Poluentes do Solo , Animais , Antibacterianos , Solo , Poluentes do Solo/análise , Suínos , Tetraciclinas/análise
8.
Huan Jing Ke Xue ; 41(8): 3870-3878, 2020 Aug 08.
Artigo em Zh | MEDLINE | ID: mdl-33124365

RESUMO

The contribution of crop planting to agricultural non-point source pollution should not be underestimated in China. Although many modern technologies have been developed to prevent non-point source pollution in recent decades, their impacts on pollution control in farmland are far from expectation. The application of technologies for non-point source pollution control for crop farming has been delayed due to unclear technical parameters and application effectiveness. Therefore, based on studies of the non-point source pollution control for crop farming in China and abroad that were published in the last 20 years, the present research was carried out to determine the development process of planting non-point source pollution control technologies and to illuminate the framework construction. The technologies in different fields and directions were compared by their effects on fertilizer input,yield, and pollutant emission. The development trend in the field of prevention and control technologies for planting non-point source pollution was subsequently predicted. In addition, a technical framework was developed with 3 fields (pollutant source reduction, pollutant interception in the migration process, and nutrient recycling) and 14 directions. The analysis showed that the technologies for reducing pollutants from the source have attracted the most (and increasing) concern with many research directions, and that many of the studies in this field have focused on the regulation of fertilizer application. On the contrary, there is a lack of technologies in the fields of pollutant process interception and nutrient recycling. Promoting nutrient-use efficiency, regulating nutrient transformation, and using soil supplements will be the main entry points for non-point source pollution control for crop farming. Furthermore, technologies will operate better with the help of farmland infrastructure and downstream purification systems.


Assuntos
Poluição Difusa , Agricultura , China , Fertilizantes , Nitrogênio/análise , Fósforo/análise
9.
Nat Commun ; 10(1): 5230, 2019 11 19.
Artigo em Inglês | MEDLINE | ID: mdl-31745089

RESUMO

The Hengduan Mountains (HDM) biodiversity hotspot exhibits exceptional alpine plant diversity. Here, we investigate factors driving intraspecific divergence within a HDM alpine species Salix brachista (Cushion willow), a common component of subnival assemblages. We produce a high-quality genome assembly for this species and characterize its genetic diversity, population structure and pattern of evolution by resequencing individuals collected across its distribution. We detect population divergence that has been shaped by a landscape of isolated sky island-like habitats displaying strong environmental heterogeneity across elevational gradients, combined with population size fluctuations that have occurred since approximately the late Miocene. These factors are likely important drivers of intraspecific divergence within Cushion willow and possibly other alpine plants with a similar distribution. Since intraspecific divergence is often the first step toward speciation, the same factors can be important contributors to the high alpine species diversity in the HDM.


Assuntos
Altitude , Biodiversidade , Variação Genética , Genoma de Planta/genética , Estudo de Associação Genômica Ampla/métodos , Salix/genética , Ecossistema , Geografia , Filogenia , Salix/classificação , Especificidade da Espécie , Sequenciamento do Exoma/métodos
10.
Huan Jing Ke Xue ; 39(6): 2936-2943, 2018 Jun 08.
Artigo em Zh | MEDLINE | ID: mdl-29965653

RESUMO

Based on the typical greenhouse vegetable production system in Siping City, Jilin Province, 124 soil samples were collected from greenhouse soils growing vegetables (GSGV), fields growing maize (FGM), and forest soil (FS) under different land utilization patterns. In addition, other samples including greenhouse vegetables (81), fertilizers (50), and irrigation water (10) were also collected in the studied region. To illustrate the accumulation characteristics of heavy metals in GSGV and greenhouse vegetables, the heavy metal content of different samples was measured using inductively coupled plasma mass spectrometry (ICP-MS) technology. The results indicated that the heavy metal content in GSGV was much higher than that in FGM and FS except for lead (Pb). Heavy metals including cadmium (Cd), copper (Cu), chromium (Cr), nickel (Ni), and zinc (Zn) in GSGV presented with various degrees of accumulation. The mean value of Cd content in the soils in the investigation region was 0.45 mg·kg-1, with about 42.8% of all the soil samples exceeding the Cd content criterion of the Environmental Quality Evaluation Standard for Farmland in Greenhouse Vegetable Production (HJ 333-2006). The content of the other heavy metals was in the normal range, and all met the regulations of the standard. In comparison with different vegetable categories, leafy vegetables showed much higher heavy metal concentrations (Cd 0.033 mg·kg-1 fresh weight) than did fruity ones. In total, about 2.5% and 1.2% of vegetable samples exceeded the regulated values of Cd and Pb recommended by the Standard of Food limits, respectively. With the cultivation time prolonged, heavy metal concentration in soils and vegetables all increased synchronously as the pH value decreased. The content of heavy metals in greenhouse vegetables was significantly influenced by soil pH and organic matter. It can be concluded that the health risk of greenhouse vegetables increased with GSGV accumulating more heavy metals due to the substantial application of chemical fertilizer and manure containing high level of heavy metals.


Assuntos
Metais Pesados/análise , Poluentes do Solo/análise , Solo/química , Verduras/química , Agricultura , China , Cidades
11.
Environ Sci Pollut Res Int ; 24(23): 19375-19385, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28674954

RESUMO

Staphylococcal enterotoxin A (SEA) was the major virulence factor of Staphylococcus aureus and a biomarker of S. aureus. To establish a fast, low cost, high accuracy, reliable, and simple method for detecting S. aureus, SEA was analyzed by HPLC-ESI-TOF. SEA was not yet commercially available in universal, so SEA was prepared before it was analyzed by HPLC-ESI-TOF. The result showed that high purified SEA was successfully prepared and SEA has normal distribution in mass spectra. A large amount of recombinant SEA (rSEA) was obtained by engineering technology and was purified by Ni affinity chromatography column, and the expression and purity of rSEA and SEA were analyzed by SDS-PAGE. The factors effected on ionization of SEA were studied, and the qualitative analysis of SEA by HPLC-ESI-TOF. The result showed that large amount of SEs expressed within a short time at 28 °C or thereabouts, and there was no impurity bands in electrophorogram after rSEA was purified by Ni affinity chromatography column. In addition, the SEA which had homologous AA sequence with wild SEA was made by rSEA. The retention of SEA in column and ionization of SEA in ESI-TOF were studied for qualitative analysis of S. aureus. The result showed that the content of formic acid in mobile phase was an important factor for ionization of SEs in ESI-TOF. And the result provided theoretical foundation for qualitative detection of S. aureus. [SEs + nH+ + mNH4+] n+m+ was shown on ESI-TOF spectra when SEA was detected by ESI-TOF in positive ion mode, and the numerical value of n+m was less than or equal to the number of basic amino acids in SEs. This method was applied to determine SEA in water samples preliminarily, and the detection limit of SEA in spiked water sample was 3 mg/kg. The limit of detection of 3 mg/kg was low sensitivity for low molecular weight matters, but it was high sensitivity for SEA which had a high molecular weight of 27 kDa. Of SEA, 3 mg/kg was equivalent to 10-4 mmol/kg of SEA. This study can provide evidence for establishing method to determine SEA in real samples.


Assuntos
Técnicas de Química Analítica/métodos , Enterotoxinas/análise , Enterotoxinas/biossíntese , Staphylococcus aureus/química , Água/química , Cromatografia de Afinidade , Cromatografia Líquida de Alta Pressão , Clonagem Molecular , Enterotoxinas/isolamento & purificação , Engenharia Genética , Espectrometria de Massas , Proteínas Recombinantes/análise , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/isolamento & purificação , Staphylococcus aureus/genética
12.
J Chromatogr A ; 1446: 59-69, 2016 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-27086566

RESUMO

A novel, rapid and simple analytical method was developed for the quantitative determination of crocin, crocetin and geniposide in soft drink, pastry and instant noodles. The solid samples were relatively homogenized into powders and fragments. The gardenia yellow colorants were successively extracted with methanol using ultrasound-assisted extraction. The analytes were quantitatively measured in the extracts by liquid chromatography coupled with electrospray ionization tandem mass spectrometry. High correlation coefficients (r(2)>0.995) of crocin, crocetin and geniposide were obtained within their linear ranges respectively (50-1000ng/mL, 50-1000ng/mL, 15-240ng/mL) by external standard method. The limits of detection (LODs) were 0.02µg/g for crocin, 0.01µg/g for crocetin and 0.002µg/g for geniposide. And the limits of quantitation (LOQs) were in the ranges of 0.05-0.45µg/g for crocin, and in the ranges of 0.042-0.32µg/g for crocetin, and in the ranges of 0.02-0.15µg/g for geniposide in soft drink, pastry and instant noodles samples. The average recoveries of crocin, crocetin and geniposide ranged from 81.3% to 117.6% in soft drink, pastry and instant noodles. The intra- and inter-day precisions were respectively in the range of 1.3-4.8% and 1.7-11.8% in soft drink, pastry and instant noodle. The developed methods were successfully validated and applied to the soft drink, pastry, and instant noodles collected from the located market in Beijing from China. Crocin, crocetin and geniposide were detected in the collected samples. The average concentrations ranged from 0.84 to 4.20mg/g for crocin, and from 0.62 to 3.11mg/g for crocetin, and from 0.18 to 0.79mg/g for gardenia in various food samples. The method can provide evidences for government to determine gardenia yellow pigments and geniposide in food.


Assuntos
Carotenoides/análise , Corantes/análise , Análise de Alimentos , Gardenia/química , Iridoides/análise , Extratos Vegetais/química , Pequim , Bebidas Gaseificadas/análise , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas em Tandem , Vitamina A/análogos & derivados
13.
Anal Chim Acta ; 748: 89-94, 2012 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-23021812

RESUMO

An ultrasensitive electrochemical impedance spectroscopic deoxyribonucleic acid biosensor has been developed based on the conformational change of the deoxyribonucleic acid recognition interface with lodging probes. Pairing process leads to desorption of deoxyribonucleic acid bases from the gold surface, leading to a significant change of the interfacial conformation and the charge transfer resistance. Remarkably low detection limits down to 40 fM are thus obtained without any additional amplification step.


Assuntos
Técnicas Biossensoriais , DNA/química , Técnicas Eletroquímicas , Espectroscopia Dielétrica , Limite de Detecção , Modelos Moleculares , Conformação Molecular
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA