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1.
Aging (Albany NY) ; 162024 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-38990203

RESUMEN

Atherosclerosis (AS) is the main pathological basis of cardiovascular diseases such as coronary heart disease. Black phosphorus quantum dots (BPQDs) are a novel nanomaterial with good optical properties and biocompatibility, which was applied in the treatment of AS in mice, with good results shown in our previous study. In this study, BPQDs were injected into high-fat diet-fed apolipoprotein E knockout mice as a preventive drug for 12 weeks. Simvastatin, a classic preventive drug for AS, was used as a control to verify the preventive effect of BPQDs. The results showed that after preventive treatment with BPQDs, the plaque area in mice was significantly reduced, the vascular elasticity was increased, and serum lipid levels were significantly lower than those in the model group. To explore the mechanism, macrophages were induced to become foam cells using oxidized low-density lipoprotein. We found that BPQDs treatment could increase cell autophagy, thereby regulating intracellular lipid metabolism. Taken together, these data revealed that BPQDs may serve as a functional drug in preventing the development of AS.

2.
Genes (Basel) ; 15(6)2024 May 26.
Artículo en Inglés | MEDLINE | ID: mdl-38927627

RESUMEN

The Cosmonaut Sea is one of the least accessed regions in the Southern Ocean, and our knowledge about the fish biodiversity in the region is sparse. In this study, we provided a description of demersal fish diversity in the Cosmonaut Sea by analysing cytochrome oxidase I (COI) barcodes of 98 fish samples that were hauled by trawling during the 37th and 38th Chinese National Antarctic Research Expedition (CHINARE) cruises. Twenty-four species representing 19 genera and 11 families, namely, Artedidraconidae, Bathydraconidae, Bathylagidae, Channichthyidae, Liparidae, Macrouridae, Muraenolepididae, Myctophidae, Nototheniidae, Paralepididae and Zoarcidae, were discriminated and identified, which were largely identical to local fish occurrence records and the general pattern of demersal fish communities at high Antarctic shelf areas. The validity of a barcoding gap failed to be detected and confirmed across all species due to the indicative signals of two potential cryptic species. Nevertheless, DNA barcoding still demonstrated to be a very efficient and sound method for the discrimination and classification of Antarctic fishes. In the future, various sampling strategies that cover all geographic sections and depth strata of the Cosmonaut Sea are encouraged to enhance our understanding of local fish communities, within which DNA barcoding can play an important role in either molecular taxonomy or the establishment of a dedicated local reference database for eDNA metabarcoding analyses.


Asunto(s)
Biodiversidad , Código de Barras del ADN Taxonómico , Complejo IV de Transporte de Electrones , Peces , Animales , Código de Barras del ADN Taxonómico/métodos , Peces/genética , Peces/clasificación , Regiones Antárticas , Complejo IV de Transporte de Electrones/genética , Filogenia , Océanos y Mares
3.
Genes (Basel) ; 15(2)2024 02 13.
Artículo en Inglés | MEDLINE | ID: mdl-38397224

RESUMEN

In a past study, the team used specific-locus amplified fragment sequencing (SLAF sequencing) to detect single-nucleotide polymorphisms (SNPs) contributing to the differences in lambing numbers in Xinjiang sheep. This study verified the correlation between the COIL gene and lambing number characters in sheep and explored its possible mechanism of action. In this study, three SNPs in the COIL gene, namely COILSNP1 (rs7321466), COILSNP2 (rs7314134), and COILSNP3 (rs7321563), were explored in terms of their possible mechanism of action. A tissue expression profiling analysis revealed that the COIL gene was significantly more expressed in the uterus and ovaries than in other tissues (p < 0.05), whereas an association analysis revealed that the number of lambs born was significantly different among individuals with different genotypes of this COILSNP1 (p < 0.05). The Cell Counting Kit-8(CCK-8) revealed that the overexpression of the COIL gene significantly increased the proliferation of mouse ovarian fibroblasts and sheep fibroblasts (p < 0.05). The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) revealed that the overexpression of the COIL gene significantly increased the activity of sheep fibroblasts (p < 0.01) and mouse ovarian fibroblasts (p < 0.05). The overexpression of the COIL gene affected the biogenesis pathway of spliceosomal U snRNPs by validating protein network connections. This activity affects ovulation, embryonic development, and changes in lambing size in sheep.


Asunto(s)
Proteínas Nucleares , Ovulación , Parto , Ovinos , Animales , Femenino , Ratones , Embarazo , Genotipo , Fenotipo , Polimorfismo de Nucleótido Simple/genética , Ovinos/genética , Proteínas Nucleares/genética
4.
Cell Signal ; 112: 110927, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37844713

RESUMEN

During the process of atherosclerosis (AS), hypoxia induces plaque macrophage inflammation, promoting lipid accumulation. Autophagy is a cell homeostasis process that increases tolerance to stressors like oxidative stress and hypoxia. However, the specific mechanism by which hypoxia initiates autophagy and the inflammation of macrophages remains to be elucidated. Here, we found that hypoxia-induced macrophage inflammation was mediated by autophagy. Then, the effect of hypoxia on autophagy was investigated in terms of post-translational modifications of proteins. The results showed that desialylation of the autophagy protein ATG5 under hypoxic conditions enhanced protein stability by affecting its charge effect and promoted the formation of the ATG5-ATG12-ATG16L complex, further increasing autophagosome formation. And NEU1, a key enzyme in sialic acid metabolism, was significantly up-regulated under hypoxic conditions and was identified as an interacting protein of ATG5, affecting the sialylation of ATG5. In addition, the knockdown or inhibition of NEU1 reversed hypoxia-induced autophagy and inflammatory responses. In conclusion, our data reveal a key mechanism of autophagy regulation under hypoxia involving ATG5 sialylation and NEU1, suggesting that NEU1 may be a potential target for the prevention and treatment of atherosclerosis.


Asunto(s)
Aterosclerosis , Neuraminidasa , Humanos , Neuraminidasa/metabolismo , Macrófagos/metabolismo , Inflamación , Hipoxia , Autofagia , Proteína 5 Relacionada con la Autofagia/genética , Proteína 5 Relacionada con la Autofagia/metabolismo
5.
Ultrason Sonochem ; 95: 106383, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-37004413

RESUMEN

Pericarpium Citri Reticulatae 'Chachiensis' (PCRC), the premium aged pericarps of Pericarpium Citri Reticulatae, is widely used in traditional Chinese medicines with a diversity of promising bioactivity. Herein we report the extraction, characterization and underlying mechanism of anti-metabolic syndrome of an arabinan-rich polysaccharide from PCRC (PCRCP). This polysaccharide was obtained in a 7.0% yield by using ultrasound-assisted extraction under the optimized conditions of 30 mL/g liquid-to-solid ratio, 250 W ultrasound power for 20 min at 90 °C with pH 4.5. The PCRCP with an average molecular weight of 122.0 kDa, is mainly composed of D-galacturonic acid, arabinose and galactose, which may link via 1,4-linked Gal(p)-UA, 1,4-linked Ara(f) and 1,4-linked Gal(p). Supplementation with PCRCP not only effectively alleviated the weight gain, adiposity and hyperglycemia, but also regulated the key metabolic pathways involved in the de novo synthesis and ß-oxidation of fatty acid in high-fat diet (HFD)-fed mice. Furthermore, PCRCP treatment caused a significant normalization in the intestinal barrier and composition of gut microbiota in mice fed by HFD. Notably, PCRCP selectively enriched Lactobacillus johnsonii at the family-genus-species levels, a known commensal bacterium, the level of which was decreased in mice fed by HFD. The depletion of microbiome induced by antibiotics, significantly compromised the effects of anti-metabolic syndrome of PCRCP in mice fed by HFD, demonstrating that the protective phenotype of PCRCP against anti-obesity is dependent on gut microbiota. PCRCP is exploitable as a potential prebiotic for the intervention of obesity and its complications.


Asunto(s)
Medicamentos Herbarios Chinos , Microbioma Gastrointestinal , Ratones , Animales , Ultrasonido , Medicina Tradicional China , Obesidad/tratamiento farmacológico , Ratones Endogámicos C57BL
6.
Nurs Open ; 10(5): 3153-3163, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36564925

RESUMEN

AIM: The aim was to examine the effect of role overload, work addiction and leader-member exchange on missed nursing care. DESIGN: A cross-sectional study. METHODS: Chinese registered nurses from five Sichuan province public hospitals were studied from March 2022-May 2022. The measurements were derived from a questionnaire on role overload, work addiction, missed nursing care, leader-member exchange and a sociodemographic datasheet. Descriptive statistics and inferential statistics were conducted (N = 403). RESULTS: Role overload was associated with missed nursing care, and work addiction played a mediation role. Leader-member exchange negatively predicted work addiction and played a moderating role between role overload and work addiction. The effect of role overload on work addiction was attenuated when the level of leader-member exchange was higher. Promoting leader-member exchange could mitigate how role overload undermines missed nursing care.


Asunto(s)
Liderazgo , Personal de Enfermería en Hospital , Humanos , Estudios Transversales , Actitud del Personal de Salud , China
7.
Animals (Basel) ; 12(12)2022 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-35739827

RESUMEN

Animal growth traits are directly linked with the economics of livestock species. A somatostatin DNA vaccine has been developed to improve the growth of animals. However, the growth-promoting effect is still unsatisfying. The current study aimed to evaluate the effect of a novel eukaryotic dual expression vaccine known as pIRES-S/CST14-S/2SS, which encodes the genes obtained by fusing somatostatin (SS) and cortistatin (CST) into hepatitis B surface antigen (HBsAg). After transfection into GH3 cells with pIRES-S/CST14-S/2SS, green fluorescence signals were observed by fluorescence microscopy, suggesting the effective expression of CST and SS in GH3 cells using the IRES elements. Subsequently, both GH and PRL levels were found to be significantly lower in pIRES-S/CST14-S/2SS-treated cells as compared to the control group (p < 0.05). Furthermore, the antibody level, hormone secretion, and weight gain in the mice injected with novel recombinant plasmids were also evaluated. The anti-SS antibodies were detectable in all vaccine treated groups, resulting in significantly higher levels of GH secretion (p < 0.05). It is worth mentioning that pIRES-S/CST14-S/2SS (10 µg/100 µL) vaccinated mice exhibited a higher body weight gain in the second immunization period. This study increases the understanding of the relationship between somatostatin and cortistatin, and may help to develop an effective growth-promoting DNA vaccine in animals.

8.
Front Neurorobot ; 15: 570507, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33762921

RESUMEN

The success of a robotic pick and place task depends on the success of the entire procedure: from the grasp planning phase, to the grasp establishment phase, then the lifting and moving phase, and finally the releasing and placing phase. Being able to detect and recover from grasping failures throughout the entire process is therefore a critical requirement for both the robotic manipulator and the gripper, especially when considering the almost inevitable object occlusion by the gripper itself during the robotic pick and place task. With the rapid rising of soft grippers, which rely heavily on their under-actuated body and compliant, open-loop control, less information is available from the gripper for effective overall system control. Tackling on the effectiveness of robotic grasping, this work proposes a hybrid policy by combining visual cues and proprioception of our gripper for the effective failure detection and recovery in grasping, especially using a proprioceptive self-developed soft robotic gripper that is capable of contact sensing. We solved failure handling of robotic pick and place tasks and proposed (1) more accurate pose estimation of a known object by considering the edge-based cost besides the image-based cost; (2) robust object tracking techniques that work even when the object is partially occluded in the system and achieve mean overlap precision up to 80%; (3) contact and contact loss detection between the object and the gripper by analyzing internal pressure signals of our gripper; (4) robust failure handling with the combination of visual cues under partial occlusion and proprioceptive cues from our soft gripper to effectively detect and recover from different accidental grasping failures. The proposed system was experimentally validated with the proprioceptive soft robotic gripper mounted on a collaborative robotic manipulator, and a consumer-grade RGB camera, showing that combining visual cues and proprioception from our soft actuator robotic gripper was effective in improving the detection and recovery from the major grasping failures in different stages for the compliant and robust grasping.

9.
J Mater Chem B ; 9(10): 2515-2523, 2021 03 17.
Artículo en Inglés | MEDLINE | ID: mdl-33659973

RESUMEN

The precise operation of the hypoxic tumor microenvironment presents a promising way to improve treatment efficacy, in particular in tumor synergistic phototherapy. This work reports an innovative approach to build adenosine triphosphate-modified hollow ceria nanozymes (ATP-HCNPs@Ce6) that manipulate tumor hypoxia to effectively achieve drug delivery. Hollow ceria nanoparticles (HCNPs) exhibit a controllable hollow structure through varying nitric acid concentrations in the nanocomposites. Specifically, ATP modification makes HCNPs exceptionally biocompatible and stable and acts as a regulator of HCNP enzymatic activity. In the stage of drug loading, newly prepared ATP-HCNPs@Ce6 serves as an in situ oxygen-generating agent because of its ability to simulate catalase. Therefore, ATP-HCNPs@Ce6 has adjustable enzymatic properties that act like a "switch" to selectively supply oxygen in response to high levels of hydrogen peroxide expression and the slightly acidic lysosomal environment of the tumor to enhance lysosome-targeted photodynamic therapy. Moreover, the obvious anticancer effects of ATP-HCNPs@Ce6 are demonstrated in vitro and in vivo. Overall, a simple and rapid self-assembly strategy to form and modify multifunctional HCNPs is reported, which may further propel their application in the field of precision tumor treatment.


Asunto(s)
Materiales Biomiméticos/química , Catalasa/metabolismo , Cerio/química , Lisosomas/metabolismo , Terapia Molecular Dirigida/métodos , Nanopartículas/química , Fototerapia/métodos , Adenosina Trifosfato/química , Línea Celular Tumoral , Humanos , Peróxido de Hidrógeno/metabolismo
10.
J Mater Chem B ; 8(7): 1481-1488, 2020 02 21.
Artículo en Inglés | MEDLINE | ID: mdl-31996879

RESUMEN

Chlorin e6 (Ce6) is a second generation photosensitizer for photodynamic therapy (PDT). However, free Ce6 still has some defects leading to reduced clinical efficacy, such as easy agglomeration in a physiological environment and poor accumulation in tumor tissue. In order to solve these problems, a hyaluronic acid (HA) modified zeolitic imidazolate framework-8 (ZIF-8) based Ce6 (ZIF-8@Ce6-HA) therapeutic agent is constructed for PDT by one-pot encapsulation and self-assembly. ZIF-8@Ce6-HA exhibits acceptable encapsulation efficiency, effective cell uptake and good biocompatibility. Moreover, the results of in vitro anticancer experiments demonstrated that the ZIF-8@Ce6-HA group exhibited greater cytotoxicity after irradiation than the free Ce6 group, which caused about 88.4% of HepG2 cells to die since ROS is produced by PDT. Additionally, the data of inductively coupled plasma mass spectrometry indicated that modification of HA increased the blood circulation time and reduced the systemic toxicity of ZIF-8@Ce6. In summary, this work created an interesting Ce6 therapeutic agent for PDT and provided the data for HA regarding the improvement in biocompatibility and biological half-life of metal organic frameworks.


Asunto(s)
Antineoplásicos/farmacología , Materiales Biocompatibles/farmacología , Estructuras Metalorgánicas/farmacología , Fotoquimioterapia , Fármacos Fotosensibilizantes/farmacología , Polisacáridos/química , Porfirinas/farmacología , Animales , Antineoplásicos/síntesis química , Antineoplásicos/química , Materiales Biocompatibles/síntesis química , Materiales Biocompatibles/química , Supervivencia Celular/efectos de los fármacos , Clorofilidas , Sistemas de Liberación de Medicamentos , Femenino , Células Hep G2 , Humanos , Neoplasias Hepáticas Experimentales/tratamiento farmacológico , Neoplasias Hepáticas Experimentales/patología , Estructuras Metalorgánicas/síntesis química , Estructuras Metalorgánicas/química , Ratones , Ratones Endogámicos BALB C , Tamaño de la Partícula , Fármacos Fotosensibilizantes/química , Porfirinas/química , Propiedades de Superficie , Distribución Tisular
11.
Biosens Bioelectron ; 145: 111677, 2019 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-31581070

RESUMEN

In this work, an innovative metal nanowire-based biosensor designed for the quantitative detection of semaphorin 3E (Sema 3E), a potential biomarker for several diseases such as atherosclerosis and systemic sclerosis, was proposed. For the biosensor fabrication, novel trimetallic CuAuPd nanowire networks (NNWs) were synthesized to utilize as a multifunctional substrate for electron transfer, antibody immobilization and signal amplification via catalyzing the decomposition of hydrogen peroxide. A facile one-step approach was employed at room temperature and atmospheric pressure to synthesize the CuAuPd NNWs, exhibiting advantages of high specific surface area, excellent electron transport property, superior catalytic property, and excellent biocompatibility. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and atomic force microscopy (AFM) was examined to determine the successful fabrication process of the sensor, while the electrochemical method of amperometric i-t curve was used for the detection of target. The results demonstrated accepted stability, excellent selectivity, sensitivity and accuracy, which displayed a linear range of the analyte concentration that covered 100 fg mL-1 to 10 ng mL-1, with a low detection limit of approximately 1.5 fg mL-1 (S/N = 3), achieved under optimum conditions. This result suggests that the sensor could be applied to the serum samples for Sema 3E quantitation.


Asunto(s)
Técnicas Biosensibles , Técnicas Electroquímicas , Nanocompuestos/química , Semaforinas/aislamiento & purificación , Cobre/química , Humanos , Nanocables/química , Paladio/química , Semaforinas/química
12.
Biosens Bioelectron ; 144: 111635, 2019 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-31513958

RESUMEN

T-2 toxin is a mycotoxin that can cause chronic illnesses, and the detection of T-2 toxin in food is critical for human health. Herein, a novel sandwich aptasensor with a dual signal amplification strategy was developed for the detection of T-2 toxin. Molybdenum disulfide-polyaniline-chitosan-gold nanoparticles (MoS2-PANI-Chi-Au) were processed to the modified glassy carbon electrode (GCE) and used as the aptasensor platform to expedite the electronics transport and immobilize the amino-terminated capture DNA probe by Au-N bonds. The reduced graphene oxide-tetraethylene pentamine-gold@platinum nanorods (rGO-TEPA-Au@Pt NRs) were first synthesized and immobilized with a signal DNA probe. Once T-2 toxin was added into the biosensing system, the aptamer would trap T-2 toxin to turn the signal off. Next, dissociative aptamer hybridized with the capture DNA probe in GCE and linked simultaneously to the signal DNA probe on rGO-TEPA-Au@Pt NRs with another end sequence of aptamer to turn the signal on. Owing to the efficient catalytic ability of bimetallic Au@Pt nanorods, the signal was perfectly amplified through the catalysis of hydrogen peroxide (H2O2) and recorded by chronoamperometry. With the outstanding augment response, the limit of detection reached 1.79 fg mL-1 (3SB/m) and a wide linear range from 10 fg mL-1 to 100 ng mL-1 was presented. The sensitivity of the aptasensor was 19.88 µA⋅µM-1⋅cm-2. Meanwhile, the DNA aptamer-bimetallic nanorod based sensing system presented excellent specificity. The developed aptasensor provides a new platform for T-2 toxin detection with low cost for real sample assays.


Asunto(s)
Aptámeros de Nucleótidos/química , Técnicas Biosensibles , Grafito/química , Toxina T-2/aislamiento & purificación , Sondas de ADN/química , Oro/química , Humanos , Nanotubos/química , Platino (Metal)/química , Toxina T-2/química , Trietilenofosforamida/química
13.
Biosens Bioelectron ; 132: 302-309, 2019 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-30884317

RESUMEN

In this work, an aptamer was used as the target capturing agent and a trimetallic signal amplification strategy based on Ce-MOF@Au and AuPtRu NPs was demonstrated for the sensitive detection of TSP-1. Herein, the synthesized AuPtRu nanocomposite (AuPtRu NPs) not only acts as the catalyst for catalyzing hydrogen peroxide but also acts as a nanocarrier for capturing the -NH2 termination single strand DNA (S1) to obtain the signal probe (SP, AuPtRu nanocomposite/S1). Then, SP was efficiently linked into TSP-1 aptamers with the addition of complementary linking strands to form M1 (SP/aptamer). The Ce-MOF@Au nanocomposites were obtained by in situ reduction and used as GCE electrode modification materials. The -NH2-modified capture probe (CP) DNA was immobilized on the surface of Ce-MOF@Au nanocomposites for hybridizing SP. In the presence of the target TSP-1, the aptamer recognizes the target and binds strongly so that SP is released from the prepared M1 and then hybridized with CP. When the detection solution contains an electrochemical matrix of H2O2, AuPtRu NPs can oxidize H2O2 to obtain an enhanced signal. Furthermore, the proposed aptasensor has a very low LOD of 0.13 fg mL-1 TSP-1 in the detection range of 1 fg mL-1 to 10 ng mL-1. Moreover, the proposed platform also has application implications for other potential targets.


Asunto(s)
Aptámeros de Nucleótidos/química , Técnicas Biosensibles/métodos , Cerio/química , Estructuras Metalorgánicas/química , Nanocompuestos/química , Trombospondina 1/sangre , Técnicas Electroquímicas/métodos , Oro/química , Humanos , Ácidos Nucleicos Inmovilizados/química , Límite de Detección , Nanocompuestos/ultraestructura , Platino (Metal)/química , Rutenio/química , Trombospondina 1/análisis
14.
Biosens Bioelectron ; 131: 207-213, 2019 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-30844597

RESUMEN

We fabricate a novel electrochemical biosensor based on the specific thymine-Hg2+-thymine (T-Hg2+-T) base pair for the highly sensitive detection of mercury ions (Hg2+) and utilize toluidine blue (TB) as a redox indicator that is combined with a hybridization chain reaction (HCR) for signal amplification. The dandelion-like CuO (D-CuO) microspheres that were assembled using Au nanoparticles were first introduced as support materials, which produced more active sites for the thiolated probe (P1) combination. Then, the presence of Hg2+ induced P1 to hybridize with the other oligonucleotide (P2) through Hg2+-mediated T-Hg2+-T complexes. In addition, the partial sequence of P2 acted as an initiator sequence, which led the two hairpin DNA (H1 and H2) strands to collectively form the extended double-strand DNA through the HCR process on the electrode surface. TB was employed to interact with the double strands and produce an efficient electrochemical signal. The proposed strategy combined the amplification of the HCR and the inherent redox activity of TB and utilized D-CuO/Au composites, which exhibited high sensitivity for Hg2+ determination. Under the optimum conditions, the proposed biosensor showed a prominent response for Hg2+, including a linear range from 1 pM to 100 nM and a detection limit of 0.2 pM (S/N = 3). Moreover, the new biosensor proved its potential application for trace Hg2+ determination in environmental water samples.


Asunto(s)
Técnicas Biosensibles , Técnicas Electroquímicas , Mercurio/aislamiento & purificación , Contaminantes Químicos del Agua/aislamiento & purificación , ADN/química , Oro/química , Límite de Detección , Mercurio/química , Nanopartículas del Metal/química , Microesferas , Oligonucleótidos/química , Contaminantes Químicos del Agua/química
15.
Biosens Bioelectron ; 129: 139-146, 2019 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-30690178

RESUMEN

Low molecular weight pollutants from foods have aroused global attention due to their toxicity after long-time exposure. There is an increased demand for appropriate methods to detect these pollutants in foods. In this study, a brand-new type of nano metal-organic coordination polymers (MOCPs) nanocarriers (3D sakura-shaped copper (II) ions@L-glutamic acid (L-Glu)) has been first synthesized. We herein demonstrate a facile chelated method that allows the combination of copper (II) ions and L-Glu. A series of controlled experiments have revealed that the reaction time and the ratio of reactants played the crucial roles in affecting the morphology of the final product. 3D sakura-shaped Cu@L-Glu combined with palladium-platinum nanoparticle (Pd-PtNPs) to obtain Cu@L-Glu/Pd-PtNPs acting as the signal tag, which applied in electrochemical aptasensor for ultrasensitive detection of zearalenone (ZEN). A glassy carbon electrode was first modified with spherical Au-PANI-Au nanohybrids to enhance the conductivity and immobilize more amino modified ZEN aptamer. Cu@L-Glu/Pd-PtNPs were labeled with Complementary DNA (partial matching with ZEN aptamer) to form bioconjugates for signal amplification. After the hybridization reaction of ZEN aptamer and the bioconjugates, a significant electrochemical signal from the catalysis of H2O2 by Cu@L-Glu/Pd-PtNPs can be observed. ZEN competed with bioconjugates for binding to ZEN aptamer, resulting in decreased the electrochemical signal. Chronoamperometry was applied to record the final electrochemical signals. Under optimal conditions, the electrochemical aptasensor exhibited desirable sensitive detection of ZEN with a wide linearity ranging from 1 fg/mL to 100 ng/mL and a relatively low detection limit of 0.45 fg/mL (S/N = 3). Furthermore, the proposed electrochemical aptasensor shows excellent selectivity to the ZEN in the presence of possible interfering substances, and has potential application for ZEN detection in food samples.


Asunto(s)
Aptámeros de Nucleótidos/química , Técnicas Biosensibles/métodos , Cobre/química , Ácido Glutámico/química , Nanoestructuras/química , Polímeros/química , Zearalenona/análisis , Técnicas Electroquímicas/métodos , Análisis de los Alimentos/métodos , Contaminación de Alimentos/análisis , Oro/química , Límite de Detección
16.
Mikrochim Acta ; 185(1): 55, 2017 12 18.
Artículo en Inglés | MEDLINE | ID: mdl-29594375

RESUMEN

This research describes a nanowire network-based method for detecting the activity of myeloperoxidase (MPO), a biomarker of acute coronary syndromes (ACS). Trimetallic CuPdPt nanowire networks (CuPdPt NWNWs) were prepared by a one-step chemical reduction method. The metallic precursors quickly form nanowire network structures without the need for additional capping agents or surfactants. This process creates a product with a clean surface. The NWNWs were dropped onto a glassy carbon electrode (GCE) to obtain a sensor with good catalytic activity towards the reduction of hydrogen peroxide (H2O2), which was used as an electrochemical probe working at -0.4 V (vs. SCE). It also provided a large surface for further modification. Next, an antibody against MPO was immobilized on the modified GCE via the stable conjunction between Cu, Pt, Pd and amino groups. Upon binding of MPO to the antibody on the GCE, the current response to H2O2 was reduced by 35 µA·cm-2. The immunosensor had a linear response within the 100 fg·mL-1 to 50 ng·mL-1 MPO concentration range and a 33 fg·mL-1 detection limit (at an S/N ratio of 3). The recovery of spiked serum samples ranged from 99.8 to 103.6%. This result suggests that the method can be applied to the quantitation of MPO in human serum samples. Graphical abstract A trimetallic CuPdPt nanowire networks was placed on a glassy cabon electrode (GCE) to design an immunosensor for myeloperoxidase (MPO), a biomarker for the acute coronary syndrome (ACS). Antibody against MPO was immobilized on the network via conjugation between Cu, Pt, Pd and amino groups. Amperometric i-t measurements were conducted to quantify the amount of MPO that binds to the antibody on the surface of the modified GCE.


Asunto(s)
Técnicas Biosensibles/métodos , Electroquímica/métodos , Inmunoensayo/métodos , Nanocables/química , Peroxidasa/metabolismo , Cobre/química , Electrodos , Humanos , Peróxido de Hidrógeno/metabolismo , Paladio/química , Peroxidasa/sangre , Platino (Metal)/química
17.
J Pept Sci ; 19(1): 1-8, 2013 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-23136049

RESUMEN

This study investigates whether the B chain of ß-bungarotoxin exerted antibacterial activity against Escherichia coli (Gram-negative bacteria) and Staphylococcus aureus (Gram-positive bacteria) via its membrane-damaging activity. The B chain exhibited a growth inhibition effect on E. coli but did not show a bactericidal effect on S. aureus. The B-chain bactericidal action on E. coli positively correlated with an increase in membrane permeability in the bacterial cells. Lipopolysaccharide (LPS) layer destabilization and lipoteichoic acid (LTA) biosynthesis inhibition in the cell wall increased the B-chain bactericidal effect on E. coli and S. aureus. The B chain induced leakage and fusion in E. coli and S. aureus membrane-mimicking liposomes. Compared with LPS, LTA notably suppressed the membrane-damaging activity and fusogenicity of the B chain. The B chain showed similar binding affinity with LPS and LTA, whereas LPS and LTA binding differently induced B-chain conformational change as evidenced by the circular dichroism spectra. Taken together, our data indicate that the antibacterial action of the B chain is related to its ability to induce membrane permeability and suggest that the LPS-induced and LTA-induced B-chain conformational change differently affects the bactericidal action of the B chain.


Asunto(s)
Antibacterianos/farmacología , Bungarotoxinas/farmacología , Antibacterianos/química , Bungarotoxinas/química , Membrana Celular/efectos de los fármacos , Escherichia coli/efectos de los fármacos , Pruebas de Sensibilidad Microbiana , Microscopía Electrónica de Rastreo , Staphylococcus aureus/efectos de los fármacos
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