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1.
Crit Rev Biotechnol ; 43(4): 503-520, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35430940

RESUMO

Chemical resources and techniques have long been used in the history of bulk polyester production and still dominate today's chemical industry. The sustainable development of the polyester industry demands more renewable resources and environmentally benign polyester products. Accordingly, the rapid development of biotechnology has enabled the production of an extensive range of aliphatic and aromatic polyesters from renewable bio-feedstocks. This review addresses the production of representative commercial polyesters (polyhydroxyalkanoates, polylactic acid, poly ε-caprolactone, polybutylene succinate, polyethylene terephthalate, polybutylene terephthalate, polypropylene terephthalate, polyethylene furandicarboxylate, polypropylene furandicarboxylate, and polybutylene furandicarboxylate) or their monomers (lactic acid, succinic acid, 1,4-butanediol, ethylene glycol, terephthalic acid, 1,3-propanediol, and 2,5-furandicarboxylic acid) from renewable bioresources. In addition, this review summarizes advanced biotechniques in the treatment of polyester wastes, representing the near-term trends and future opportunities for waste-to-value recycling and the remediation of polyester wastes under sustainable models. For future prospects, it is essential to further expand: non-food bioresources, optimize bioprocesses and biotechniques in the preparation of bioderived or biodegradable polyesters with promising: material performance, biodegradability, and low production cost.


Assuntos
Poli-Hidroxialcanoatos , Polipropilenos , Poliésteres , Biotecnologia/métodos , Ácido Láctico
2.
Biotechnol Lett ; 42(4): 633-640, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31965395

RESUMO

OBJECTIVES: Acetyl-CoA is a precursor for phloroglucinol (PG), and pyruvate is one of the sources of intracellular acetyl-CoA. Therefore, enhancing intracellular pyruvate levels may help to improve the anabolic pathway of PG. RESULTS: In this study, the effects of phosphoenolpyruvate carboxykinase (PckA, encoded by pckA) or triosephosphate isomerase (TpiA, encoded by tpiA) overexpression on the production of PG were studied. Overexpression of pckA or tpiA could enhance the pyruvate anabolic pathway in shake-flask culture compared to the control strain, and the concentration of PG also increased by 44% and 92%, respectively. In addition, the acetate levels were all down regulated by the overexpression of the two genes to some extent and lower acetate level resulted in lower ATP pool and higher survival rate. CONCLUSIONS: These results indicate that overexpression of pckA or tpiA can enhance the pyruvate "pool" and PG production in Escherichia coli, which provides a new reference for further increasing the production of PG.


Assuntos
Escherichia coli/crescimento & desenvolvimento , Floroglucinol/metabolismo , Fosfoenolpiruvato Carboxiquinase (ATP)/metabolismo , Ácido Pirúvico/metabolismo , Triose-Fosfato Isomerase/metabolismo , Técnicas de Cultura Celular por Lotes/instrumentação , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Fermentação , Fosfoenolpiruvato Carboxiquinase (ATP)/genética , Plasmídeos/genética , Transformação Bacteriana , Triose-Fosfato Isomerase/genética
3.
Analyst ; 145(1): 150-156, 2019 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-31720590

RESUMO

The DNA tetrahedron has developed a broad spectrum of applications in biosensor construction thanks to its excellent mechanical rigidity and structural stability. However, how to construct a highly sensitive biosensor using a DNA tetrahedron is still a challenge. In this work, an ultrasensitive electrochemical biosensor based on a DNA tetrahedral nanostructure was developed with the help of synergy from proximity-dependent hybridization. To decrease the steric hindrance of DNA tetrahedra to proximity-dependent hybridization, the detection signal was set on the inclined side chain structure of a DNA tetrahedral sensing system. Additionally, when the target hybridized with the DNA probe, the ferrocene (Fc) labeled on the end of the DNA probe was driven close to the surface of the biosensor, providing a sensitive faradaic current. The experimental results exhibited a good linear relationship from 1 fM to 10 pM with a linear correlation coefficient of 0.9977, and a high sensitivity with a detection limit of 0.2 fM. Our DNA biosensor also showed good stability according to electrode characterization and target detection at different time scales and the anti-jamming capabilities in a complicated biological extraction environment were excellent. The electrochemical sensing system established here has greatly improved the detection sensitivity of a DNA biosensor based on a DNA tetrahedron, which will further promote its practical applications.


Assuntos
Técnicas Biossensoriais/métodos , Sondas de DNA/química , DNA/sangue , Técnicas Eletroquímicas/métodos , Animais , Bovinos , DNA/genética , Sondas de DNA/genética , Técnicas Eletroquímicas/instrumentação , Eletrodos , Compostos Ferrosos/química , Ouro/química , Limite de Detecção , Listeria monocytogenes/química , Metalocenos/química , Conformação Molecular , Nanoestruturas/química , Hibridização de Ácido Nucleico
4.
Acta Pharmacol Sin ; 39(2): 243-250, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28905937

RESUMO

Aberrant fibroblast growth factor receptor (FGFR) activation is found across a diverse spectrum of malignancies, especially those lacking effective treatments. SOMCL-085 is a novel FGFR-dominant multi-target kinase inhibitor. Here, we explored the FGFR-targeting anticancer activity of SOMCL-085 both in vitro and in vivo. Among a panel of 20 tyrosine kinases screened, SOMCL-085 potently inhibited FGFR1, FGFR2 and FGFR3 kinase activity, with IC50 values of 1.8, 1.9 and 6.9 nmol/L, respectively. This compound simultaneously inhibited the angiogenesis kinases VEGFR and PDGFR, but without obvious inhibitory effect on other 12 tyrosine kinases. In 3 representative human cancer cell lines with different mechanisms of FGFR activation tested, SOMCL-085 (20-500 nmol/L) dose-dependently inhibited FGFR1-3 phosphorylation and the phosphorylation of their key downstream effectors PLCγ and Erk. In 7 FGFR aberrant human cancer cell lines, regardless of the mechanistic complexity of FGFR over-activation, SOMCL-085 potently inhibited FGFR-driven cell proliferation by arresting cells at the G1/S phase. In the FGFR1-amplified lung cancer cell line H1581 xenograft mice and FGFR2-amplified gastric cancer cell line SNU16 xenograft mice, oral administration of SOMCL-085 (25, 50 mg·kg-1·d-1) for 21 days substantially suppressed tumor growth without affecting their body-weight. These results suggest that SOMCL-085 is a potent multi-target FGFR inhibitor that inhibits the FGFR-dependent neoplastic phenotypes of human cancer cells in vitro and in vivo.


Assuntos
Antineoplásicos/uso terapêutico , Naftalenos/uso terapêutico , Piperazinas/uso terapêutico , Piridinas/uso terapêutico , Receptores de Fatores de Crescimento de Fibroblastos/antagonistas & inibidores , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Feminino , Pontos de Checagem da Fase G1 do Ciclo Celular/efeitos dos fármacos , Humanos , Camundongos Nus , Naftalenos/administração & dosagem , Naftalenos/farmacologia , Piperazinas/administração & dosagem , Piperazinas/farmacologia , Piridinas/administração & dosagem , Piridinas/farmacologia , Receptores do Fator de Crescimento Derivado de Plaquetas/antagonistas & inibidores , Receptores de Fatores de Crescimento do Endotélio Vascular/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos
5.
Med Res Rev ; 35(4): 720-52, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25763934

RESUMO

Chronic lymphocytic leukemia (CLL) remains the most incurable leukemia. Early chemotherapeutic treatments, including alkylating agents, purine nucleoside derivatives, and immunotherapeutic antibodies, only show limited benefits for patients but severe off-target related side effects. Recent advances in understanding of the critical molecular pathways of regulating proliferation and survival of B-CLL cells have spurred a new therapeutical strategy by selectively targeting phosphoinositide 3-kinase delta (PI3Kδ). Idelalisib, a first-in-class PI3Kδ-selective small molecule has received the FDA's fast-track approval in July of 2014 as a new treatment of CLL, indolent B-cell non-Hodgkin's lymphoma, and relapsed small lymphocytic lymphoma. Undoubtedly, the success of idelalisib has provided a solid support in the development of PI3Kδ-specific inhibitors and reformed the concept of treating CLL. However, the number of reported selective inhibitors of PI3Kδ is very limited and very few have advanced into clinical trials. The mechanism of their actions remains elusive. More profound understanding on the modes of action of new PI3Kδ inhibitors will further validate the PI3Kδ-targeting strategy, and help to identify biomarkers capable of stratifying patients who will most likely benefit from the therapy.


Assuntos
Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Terapia de Alvo Molecular , Inibidores de Fosfoinositídeo-3 Quinase , Animais , Ensaios Clínicos como Assunto , Humanos , Leucemia Linfocítica Crônica de Células B/enzimologia , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Proteínas Quinases/uso terapêutico , Receptores de Antígenos de Linfócitos B/metabolismo
6.
Front Neurol ; 15: 1357689, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38585350

RESUMO

Background: It is challenging yet critical to differentiate between hemorrhagic transformation (HT) and contrast extravasation on non-contrast-enhanced computed tomography (NCCT) scans following mechanical thrombectomy (MT) in patients with acute ischemic stroke. We propose a new method called the ratio of maximum density values (RMDV) to minimize the confusion of contrast extravasation and to evaluate the diagnostic significance of RMDV in predicting HT on immediate post-interventional NCCT scans. Methods: We conducted a retrospective analysis of the prospective patients' database who received MT for acute ischemic stroke caused by occlusion of the intracranial large artery and showed postinterventional cerebral hyperdensities (PCHDs) on NCCT scans immediately after MT. Based on the subsequent NCCT scans, we divided patients with PCHDs into the HT and the non-HT groups. The clinical characters and radiological details were collected and compared to the two groups. We assessed the ability of RMDV >1 to predict HT by analyzing the receiver operating characteristic curve. Results: One hundred and three patients showed PCHDs; 58 (56.31%) were classified as HT, while 45 (43.69%) were classified as non-HT. The only notable distinction between the two groups was the proportion of RMDV >1 in the HT group. The correlation between HT and RMDV >1 with an area under the curve of 0.826 (95% confidence interval, 0.739 to 0.894). The sensitivity, specificity, positive, and negative predictive values of RMDV >1 on NCCT for predicting HT were 89.66, 75.56, 82.54, and 85.00%, respectively. Conclusion: The utilization of RMDV >1 on immediate NCCT scans after MT can predict early HT with good sensitivity and specificity.

7.
Aquat Toxicol ; 257: 106423, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36822075

RESUMO

Marine organisms need to adapt to improve organismal fitness under ocean acidification (OA). Recent studies have shown that marine calcifiers can achieve acclimation by stimulating calcium binding/signaling pathways. Here, a CaM-like gene (CgCaLP-2) from oyster Crassostrea gigas which typically responded to long-term CO2 exposure (two months) rather than short-term exposure (one week) was characterized. The cloned cDNA was 678 bp and was shorter than the retrieved sequence from NCBI (1125 bp). The two sequences, designated as CgCaLP-2-v1 and CgCaLP-2-v2, were demonstrated to be different splice variants by the genome sequence analysis. Western blotting analysis revealed two bands of 23 kD and 43 kD in mantle and hemocytes, corresponding to predicted molecular weight of CgCaLP-2-v1 and CgCaLP-2-v2, respectively. The isoform CgCaLP-2-v1 (the 23 kD band) was highly stimulated in response to long-term CO2 exposure (42-day and 56-day treatment) in hemocytes and mantle tissue. The fluorescence signal of CgCaLP-2 in mantle and hemocytes became more intensive after long-term CO2 exposure. Besides, in hemocytes, CgCaLP-2 presented a higher localization on the nuclear membrane after long-term CO2 exposure (56 d). The target gene network of CgCaLP-2 was predicted, and a transcription factor (TF) gene annotated as Homeobox protein SIX4 (CgSIX4) showed a similar expressive trend to CgCaLP-2 during CO2 exposure. Suppression of CgCaLP-2 via RNA interference significantly reduced the mRNA expression of CgSIX4. The results suggested that CgCaLP-2 might mediate the Ca2+-CaLP-TF signal transduction pathway under long-term CO2 exposure. This study serves as an example to reveal that alternative splicing is an important mechanism for generation multiple protein isoforms and thus shape the plastic responses under CO2 exposure, providing new insight into the potential acclimation ability of marine calcifiers to future OA.


Assuntos
Crassostrea , Poluentes Químicos da Água , Animais , Crassostrea/metabolismo , Calmodulina/genética , Calmodulina/metabolismo , Água do Mar , Fatores de Transcrição/metabolismo , Dióxido de Carbono/toxicidade , Dióxido de Carbono/metabolismo , Concentração de Íons de Hidrogênio , Acidificação dos Oceanos , Poluentes Químicos da Água/toxicidade , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Aclimatação , Hemócitos/metabolismo
8.
Int J Biol Macromol ; 228: 808-815, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36549623

RESUMO

Composite functional materials offer promising opportunities for the development of tailored adsorbents with enhanced bioremediation potential towards toxic, carcinogenic endocrine disrupters such as Bisphenol A (BPA). Copyrolysis of microalga Chlorella sp. (CH) alkali lignin (L) with K2CO3 impregnation yielded a carbon-based composite (CHL-AC) with a micro-mesoporous structure of 0.643 cm3/g, surface area of 1414 m2/g, and BPA adsorption capacity of Qmax 316.858 mg/g. Enhanced BPA removal efficiency indicated a positive synergistic effect upon a combination of L and CH, resulting in a 73.24 % removal efficiency compared with the individual carbon components of 52.33 % for L-AC and 67.35 % for CH-AC. The kinetics and equilibrium results were described well by the pseudo second-order kinetic model and Freundlich isotherm, respectively. This paper elucidates the blending of microalgae and lignin into high-value carbon composite material, CHL-AC, with immense potential for the treatment of BPA-contaminated waters to contribute to Goal 6 (clean water and sanitation).


Assuntos
Chlorella , Microalgas , Poluentes Químicos da Água , Purificação da Água , Álcalis , Lignina , Plastificantes , Adsorção , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Carbono/química , Cinética , Concentração de Íons de Hidrogênio
9.
Food Chem ; 405(Pt A): 134811, 2023 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-36370568

RESUMO

In this study, a paper-based enzyme biosensor for hypoxanthine (Hx) was developed, enabling visual and one-step fish freshness detection. Xanthine oxidase and horseradish peroxidase were immobilized on nitrocellulose membranes with 3,3',5,5'-tetramethylbenzidine to output the colour signal. Chitosan oligosaccharide lactate-modified nitrocellulose membranes entrapped the dual-enzyme system and exhibited excellent microfluidic aggregation effect. The developed enzyme biosensor produced a linear response of 0.01-0.16 mmolL-1 with a detection limit of 8.22 µmolL-1, and was selective for Hx with recoveries of 96.13-103.11 % for fish samples. These biosensors were attached directly to the surface of fish samples and the colour was revealed within 3 min. Colour signals can be judged by the naked-eye to distinguish between fresh and spoiled fish samples and analyzed by a smartphone for quantitative analysis. The biosensor shows great potential as a powerful pattern- and reagent-free device for on-site freshness evaluation of fish.


Assuntos
Técnicas Biossensoriais , Microfluídica , Animais , Hipoxantina/análise , Colódio , Xantina Oxidase , Enzimas Imobilizadas , Peixes
10.
Environ Pollut ; 330: 121717, 2023 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-37149249

RESUMO

In this study, an autogenous N-doped biochar derived from Chlorella (CVAC) was prepared with NaOH as activator at 800 °C. The surface structural properties of CVAC and the adsorption performance of CVAC on tetracycline (TC) under different adsorption variables were analyzed and investigated using different characterization methods. The results showed that the specific surface area of CVAC was 491.16 m2 g-1 and the adsorption process was in accordance with Freundlich model and pseudo-second-order kinetic model. The maximum adsorption capacity of TC was 310.696 mg g-1 at pH 9 and 50 °C, and it was mainly physical adsorption. Furthermore, the cyclic adsorption-desorption behavior of CVAC using ethanol as eluent was evaluated and the feasibility of its long-term application was explored. CVAC also showed good cyclic performance. The variation of ΔG° and ΔH° confirmed that the adsorption of TC by CVAC was a spontaneous heat absorption process.


Assuntos
Chlorella , Poluentes Químicos da Água , Adsorção , Porosidade , Tetraciclina/química , Antibacterianos , Carvão Vegetal/química , Cinética
11.
Int J Biol Macromol ; 216: 655-669, 2022 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-35798081

RESUMO

Color indicator films for fish freshness were fabricated by incorporating κ-carrageenan (CAR) polymer with red grape skin extract (GSE) as a pH-sensing agent and silver nanoparticles (AgNPs) as an antimicrobial agent. Anthocyanins in GSE exhibited distinguished pH responsive color changes. GSE and AgNPs were well compatible with CAR with intramolecular interactions, approved by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) analysis, thermo-gravimetric analysis (TGA) and differential scanning calorimetry (DSC). GSE-containing films displayed distinguished color changes in response to pH variations and volatile ammonia. Enhanced UV blocking ability and strong antioxidant activity were revealed for GSE included films without sacrificing the physico-chemical properties of the CAR film. Films containing AgNPs showed improved mechanical strength and strong antimicrobial ability against both Escherichia coli and Staphylococcus aureus. The CAR/AgNPs/GSE film displayed a distinctive color change corresponding to changes in the total volatile basic nitrogen (TVB-N) of fish during storage. In addition, the CAR/AgNPs/GSE film showed excellent color stability to consecutive UV exposure and its storage time at 25 °C is expected to be at least 240 days, which indicates that it has high potential as an intelligent food freshness indicator film.


Assuntos
Anti-Infecciosos , Nanopartículas Metálicas , Vitis , Animais , Antocianinas/química , Antibacterianos/química , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Carragenina/química , Escherichia coli , Peixes , Embalagem de Alimentos , Nanopartículas Metálicas/química , Prata
12.
J Hazard Mater ; 425: 127887, 2022 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-34906868

RESUMO

Activated carbon (ENAC) was prepared by NaOH activation, using macroalgae (Enteromorpha clathrate) as raw material. The prepared activated carbon has a large surface area (1238.491 m2 g-1) and its total pore volume and average pore size are 0.6823 cm3g-1 and 2.2038 nm, respectively. The ENAC was characterized by SEM, FTIR, BET and XPS. The effects of contact time (0-960 min), initial tetracycline (TC) concentration (50-500 mg L-1), temperature (30-50 °C) and initial pH (2-11) on TC adsorption were evaluated. The adsorption isotherm and adsorption kinetics were discussed. Results showed that the adsorption isotherm was the Langmuir model, and the adsorption process can be described by the pseudo-second-order model. The N2 adsorption-desorption isotherm was type IV, indicating that the activated carbon had mesoporous structure. Thermodynamic analysis showed that the adsorption process was endothermic and spontaneous. The maximum adsorption capacity of TC was 381.584 mg g-1. Density functional theory (DFT) was used to simulate and analyze the adsorption process, and the influence of different types of N on the adsorption was expounded. The results showed that there are electrostatic interactions, π-π interactions and hydrogen bonding between the adsorbent and TC. These results indicated that the prepared ENAC had a great application prospect in the removal of antibiotics from aqueous solution.


Assuntos
Alga Marinha , Poluentes Químicos da Água , Adsorção , Antibacterianos , Carvão Vegetal , Concentração de Íons de Hidrogênio , Cinética , Hidróxido de Sódio , Tetraciclina , Termodinâmica
13.
Bioresour Technol ; 331: 125046, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33827016

RESUMO

A FeCl3-activated seaweed carbon/MCM-41/alginate hydrogel composite (ECAC/MCM-41/ ALG) cross-linked with calcium chloride (2% CaCl2) was synthesized for the biosorption of bisphenol A (BPA) plasticizer and basic blue (BB) dye. Biosorption uptakes of BPA and BB were performed in a batch mode with varying solution pH from 3 to 11, initial sorbate concentration from 25 to 300 mg/L, reaction time from 0 to 10 h, and biosorption temperature from 30 to 50 °C. The maximum BPA and BB uptake mechanisms were fast, which occurred within contact times of 1 and 2 h with monolayer coverage capacities of 222.32 and 190.11 mg/g at 50 °C, respectively. Cyclic biosorption/desorption behavior was evaluated via an ethanol elution to evaluate the feasibility of the ECAC/MCM-41/ALG for long-term application. Results revealed the biosorption renewability for five cycles up to 80% of the newly synthesized hydrogel composite for the purification of industrial wastewater laden with emerging contaminants.


Assuntos
Alga Marinha , Poluentes Químicos da Água , Adsorção , Alginatos , Compostos Benzidrílicos , Hidrogéis , Concentração de Íons de Hidrogênio , Cinética , Fenóis , Plastificantes , Dióxido de Silício , Termodinâmica
14.
Front Physiol ; 11: 597429, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33613300

RESUMO

Matrine, an active component of Sophora flavescens Ait root extracts, has been used in China for years to treat cancer and viral hepatitis. In the present study, we explored the effects of matrine on hyperglycemia-treated cardiomyocytes. Cardiomyocyte function, oxidative stress, cellular viability, and mitochondrial fusion were assessed through immunofluorescence, quantitative real-time PCR (qRT-PCR), enzyme-linked immunosorbent assays, and RNA interference. Matrine treatment suppressed hyperglycemia-induced oxidative stress in cardiomyocytes by upregulating transcription of nuclear factor erythroid 2-like 2 and heme oxygenase-1. Matrine also improved cardiomyocyte contractile and relaxation function during hyperglycemia, and it reduced hyperglycemia-induced cardiomyocyte death by inhibiting mitochondrial apoptosis. Matrine treatment increased the transcription of mitochondrial fusion-related genes and thus attenuated the proportion of fragmented mitochondria in cardiomyocytes. Inhibiting mitochondrial fusion by knocking down mitofusin 2 (Mfn2) abolished the cardioprotective effects of matrine during hyperglycemia. These results demonstrate that matrine could be an effective drug to alleviate hyperglycemia-induced cardiomyocyte damage by activating Mfn2-induced mitochondrial fusion.

15.
J Chromatogr Sci ; 58(8): 731-736, 2020 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-32720694

RESUMO

Au nanoparticles (AuNPs) (10-15 nm in size) were prepared and deposited on the surfaces of silica particles functionalized using 3-aminopropyltriethoxysilane as the seeds under mild conditions. Then, Au seeds grew further and formed nanosheets by the method of gold chloride hydrate reduction. 3, 5-dimethylphenyl isocyanate derivative of cellulose as chiral selector was coated on the surfaces of SiO2/Au. The obtained spheres possessed a sandwich structure in which silica bead, the packed Au NPs monolayer and cellulose derivative were the core, the interlayer and the shell, respectively. The resultant packing material was evaluated by high-performance liquid chromatography (HPLC) as chiral stationary phase (CSP). The separations of nine pairs of enantiomers were achieved in the normal-phase liquid chromatography mode. The results showed that the new CSP has sufficient interaction with the analytes due to the existence of AuNPs on silica surfaces compared with coated cellulose-silica column.

16.
Food Chem ; 319: 126542, 2020 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-32151900

RESUMO

Simple, fast and efficient method for on-site detection of meat adulteration is of increasing demand in low-resource regions. Here, a direct and visual denaturation bubble-mediated strand exchange amplification method (SEA) was developed to detect meat adulteration by targeting the mitochondrial sequence from duck, which required only a heating block. The method allowed detecting as low as 10 pg/µL duck DNA and 0.1% duck meat in binary mixtures, sufficiently meeting the demand of meat adulteration detection. Notably, the method realized instrument-free readout by significant color discrimination of positive and negative results. By coupling with fast DNA release, a direct SEA method was developed and reduced the whole detection time to 1 h, eliminating complex DNA extraction process. The developed method provided a promising strategy with integration of fast sample lysis, miniaturized reaction platform and visual readout for meat adulteration, especially suitable for low resource point-of-care settings.


Assuntos
Patos , Carne/análise , Animais , DNA/genética , Patos/genética , Temperatura
17.
Talanta ; 210: 120628, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-31987201

RESUMO

Motivated by the desire for simple, rapid and highly sensitive DNA detection, we presented a signal-on electrochemical DNA (E-DNA) sensing strategy utilizing cooperative proximity hybridization based on a G-quadruplex (G4) probe labeled with the SH, which could specifically hybridize with its target DNA in homogenous solution. In the presence of target DNA, proximity hybridization was triggered to form a Y-shaped complex and the SH was released from G4 probe stem, companied by chemisorption on the electrode surface through Au-S binding when applied a positive potential, which brought Fc labeled on the signal probe close to the electrode surface. Thus, electrochemical signal dramatically increased, ensuring the highly sensitive "signal-on" assay. Such an E-DNA sensing strategy allows for ultrasensitive DNA detection with a detection limit as low as 2.82 × 10-15 M and a wide linear response from 1.0 × 10-9 to 1.0 × 10-15 M. In addition, the powerful discriminating ability of the mismatched DNA from the perfect matched target DNA was also demonstrated. More importantly, this homogenous proximity hybridization strategy could expand to colorimetric assay by incorporating G4 probe with hemin to form DNAzyme, which could effectively catalyze ABTS to generate a visual color change. Taking the joint advantages of G4 stem-loop probe and homogenous proximity hybridization, this sensing strategy exhibits greatly enhanced sensitivity and excellent specificity, making it a promising strategy for point-of-care testing.


Assuntos
Técnicas Biossensoriais , DNA/análise , Técnicas Eletroquímicas , Quadruplex G , Hibridização de Ácido Nucleico , Eletrodos , Ouro/química , Tamanho da Partícula , Enxofre/química , Propriedades de Superfície
18.
Appl Microbiol Biotechnol ; 81(6): 1161-8, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19039582

RESUMO

To compare oxidative dissolution rates of chalcopyrite by different consortia of moderately thermophilic acidophiles, various defined mixed cultures of three bacteria Acidithiobacillus caldus s2, Leptospirillum ferriphilum YSK, and Sulfobacillus sp. LN and one archaeon Ferroplasma thermophilum L1 were studied in batch shake flask cultures incubated at 45 degrees C. Chalcopyrite dissolution was determined by measuring variations of soluble copper, ferric iron, and pH. Microbial population dynamics involved in bioleaching process were monitored using real-time quantitative polymerase chain reaction (PCR) technology. The complex consortia containing both chemoautotrophic (L. ferriphilum and At. caldus) and chemomixotrophic (Sulfobacillus LN and F. thermophilum) moderate thermophiles were found to be the most efficient in all of those tested. Mutualistic interactions between physiologically distinct moderately thermophilic acidophiles, involving transformations of iron and sulfur and transfer of organic compound, were considered to play a critical role in promoting chalcopyrite dissolution. The real-time PCR assay was reliable to analyze population dynamics of moderate thermophiles in bioleaching systems, and the analysis results were consistent with physiological characteristics of these strains.


Assuntos
Bactérias/crescimento & desenvolvimento , Bactérias/metabolismo , Cobre/metabolismo , Reação em Cadeia da Polimerase/métodos , Thermoplasmales/crescimento & desenvolvimento , Thermoplasmales/metabolismo , Bactérias/genética , Cobre/análise , Meios de Cultura/química , DNA Arqueal/genética , DNA Bacteriano/genética , Concentração de Íons de Hidrogênio , Ferro/análise , Thermoplasmales/genética
19.
Anal Sci ; 35(3): 337-341, 2019 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-30449835

RESUMO

Meat screening plays a significant role in human health and religion. But the identification methods for beef were little reported. In this work, a simple colorimetric method based on denaturation bubble-mediated strand exchange amplification (SEA) was developed for the rapid and sensitive identification of beef. The whole strategy was performed on a portable metal bath and the distinguishable color between positive and negative controls was observed directly by the naked eyes. The feasibility using crude extraction samples by a heating treatment in PBS for 2 min was evaluated in duck spiked by beef. The result demonstrated that the developed method could identify as low as 1% (w/w) beef/duck within 50 min. Meanwhile, the results showed the method had a good repeatability and specificity. Therefore, this assay allows for the rapid, sensitive, specific detection of beef, and can be recommended as an effective, promising strategy for on-site meat identification.


Assuntos
Técnicas Biossensoriais/métodos , DNA/genética , Qualidade dos Alimentos , Técnicas de Amplificação de Ácido Nucleico/métodos , Carne Vermelha/análise , Animais , Bovinos , Desnaturação de Ácido Nucleico , Carne Vermelha/classificação , Carne Vermelha/normas , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
20.
Sci Rep ; 9(1): 896, 2019 01 29.
Artigo em Inglês | MEDLINE | ID: mdl-30696841

RESUMO

M. pneumoniae infection is often ignored due to its similar clinical symptom with respiratory tract infections caused by bacteria or viruses, and thus leading to misdiagnosis and delayed treatment. It is critical to develop a rapid, sensitive and specific diagnosis method. Denaturation Bubble-mediated Strand Exchange Amplification (SEA) was established, which is an isothermal method with only a primer pair and one Bst DNA polymerase. Notably, colorimetric SEA assay was developed with simple visual readout, making instrument-independent in detection step. The method could detect as low as 1.0 × 104 copies/mL genomic DNA within 60 min. Considering that more than 80% infected patients have 1.0 × 105-1.0 × 107 copies/mL M. pneumonia DNA, SEA is available for the practical diagnosis of M. pneumoniae in clinical specimens. Through comparing 224 sputum specimens, excellent performance of SEA assay with 90.48% sensitivity and 100% specificity relative to real-time PCR was observed. Compared with LAMP, a comparable sensitivity and low false positive rate was observed for SEA method. Therefore, SEA is a promising method for detecting M. pneumoniae directly from clinical specimens, which is especially suitable for point-of-care testing in primary care facilities and resource-limited settings with minimal equipment and technological expertises.


Assuntos
Mycoplasma pneumoniae/genética , Técnicas de Amplificação de Ácido Nucleico , Pneumonia por Mycoplasma/diagnóstico , Pneumonia por Mycoplasma/microbiologia , Humanos , Técnicas de Diagnóstico Molecular , Técnicas de Amplificação de Ácido Nucleico/métodos , Técnicas de Amplificação de Ácido Nucleico/normas , RNA Ribossômico 16S , Reação em Cadeia da Polimerase em Tempo Real , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
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