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1.
World J Hepatol ; 16(3): 344-352, 2024 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-38577527

RESUMEN

Succinylation is a highly conserved post-translational modification that is processed via enzymatic and non-enzymatic mechanisms. Succinylation exhibits strong effects on protein stability, enzyme activity, and transcriptional regulation. Protein succinylation is extensively present in the liver, and increasing evidence has demonstrated that succinylation is closely related to hepatic metabolism. For instance, histone acetyltransferase 1 promotes liver glycolysis, and the sirtuin 5-induced desuccinylation is involved in the regulation of the hepatic urea cycle and lipid metabolism. Therefore, the effects of succinylation on hepatic glucose, amino acid, and lipid metabolism under the action of various enzymes will be discussed in this work. In addition, how succinylases regulate the progression of different liver diseases will be reviewed, including the desuccinylation activity of sirtuin 7, which is closely associated with fatty liver disease and hepatitis, and the actions of lysine acetyltransferase 2A and histone acetyltransferase 1 that act as succinyltransferases to regulate the succinylation of target genes that influence the development of hepatocellular carcinoma. In view of the diversity and significance of protein succinylation, targeting the succinylation pathway may serve as an attractive direction for the treatment of liver diseases.

2.
Anal Methods ; 16(14): 2019-2024, 2024 04 04.
Artículo en Inglés | MEDLINE | ID: mdl-38516852

RESUMEN

Adenosine triphosphate (ATP), as the primary energy source, plays vital roles in many cellular events. Developing an efficient assay is crucial to rapidly evaluate the level of cellular ATP. A portable and integrated electrochemiluminescence (ECL) microsensor array based on a closed bipolar electrode (BPE) was presented. In the BPE unit, the ECL chemicals and oxidation/reduction were separated from the sensing chamber. The ATP aptamer was assembled with single-stranded DNA (ssDNA) in the sensing chamber. ATP capture made the aptamer disassemble from the ssDNA and facilitated DNA-templated silver nanocluster (Ag NC) generation by the target-rolling circle amplification (RCA) reaction. The guanine-rich padlock sequence produced tandem periodic cytosine-rich sequences by the RCA, inducing Ag NC generation in the cytosine-rich region of the produced DNA strands through Ag+ reduction. The in situ Ag NC generation enhanced the circuit conductivity of the BPE and promoted the ECL reaction of [Ru(bpy)2dppz]2+/tripropylamine in the anodic reservoir. On this ECL microsensor, a good linear relationship of ATP was achieved ranging from 30 to 1000 nM. The ATP content in HepG2 cells was selectively and sensitively determined without complex pretreatment. The ATP amount of 25 cells could be successfully detected when a sub-microliter sample was loaded.


Asunto(s)
Aptámeros de Nucleótidos , Técnicas Biosensibles , Adenosina Trifosfato , Plata/química , Mediciones Luminiscentes , ADN , Aptámeros de Nucleótidos/química , Aptámeros de Nucleótidos/genética , ADN de Cadena Simple , Citosina
3.
Dev Cogn Neurosci ; 61: 101244, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-37062244

RESUMEN

Pediatric neuroimaging datasets are rapidly increasing in scales. Despite strict protocols in data collection and preprocessing focused on improving data quality, the presence of head motion still impedes our understanding of neurodevelopmental mechanisms. Large head motion can lead to severe noise and artifacts in magnetic resonance imaging (MRI) studies, inflating correlations between adjacent brain areas and decreasing correlations between spatial distant territories, especially in children and adolescents. Here, by leveraging mock-scans of 123 Chinese children and adolescents, we demonstrated the presence of increased head motion in younger participants. Critically, a 5.5-minute training session in an MRI mock scanner was found to effectively suppress the head motion in the children and adolescents. Therefore, we suggest that mock scanner training should be part of the quality assurance routine prior to formal MRI data collection, particularly in large-scale population-level neuroimaging initiatives for pediatrics.


Asunto(s)
Encéfalo , Imagen por Resonancia Magnética , Adolescente , Niño , Humanos , Imagen por Resonancia Magnética/métodos , Encéfalo/diagnóstico por imagen , Movimiento (Física) , Neuroimagen , Movimientos de la Cabeza , Artefactos
4.
Adv Sci (Weinh) ; 10(8): e2205907, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36658721

RESUMEN

Oxide-based photoelectrodes commonly generate deep trap states associated with various intrinsic defects such as vacancies, antisites, and dislocations, limiting their photoelectrochemical properties. Herein, it is reported that rhombohedral GaFeO3 (GFO) thin-film photoanodes exhibit defect-inactive features, which manifest themselves by negligible trap-states-associated charge recombination losses during photoelectrochemical water splitting. Unlike conventional defect-tolerant semiconductors, the origin of the defect-inactivity in GFO is the strongly preferred antisite formation, suppressing the generation of other defects that act as deep traps. In addition, defect-inactive GFO films possess really appropriate oxygen vacancy concentration for the oxygen evolution reaction (OER). As a result, the as-prepared GFO films achieve the surface charge transfer efficiency (ηsurface ) of 95.1% for photoelectrochemical water splitting at 1.23 V versus RHE without any further modification, which is the highest ηsurface reported of any pristine inorganic photoanodes. The onset potential toward the OER remarkably coincides with the flat band potential of 0.43 V versus RHE. This work not only demonstrates a new benchmark for the surface charge transfer yields of pristine metal oxides for solar water splitting but also enriches the arguments for defect tolerance and highlights the importance of rational tuning of oxygen vacancies.

5.
Int J Womens Health ; 14: 1547-1553, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36387328

RESUMEN

Objective: This study aimed to investigate the effect of nursing intervention based on the G-Caprini scale on the incidence of venous thromboembolism (VTE) after gynecological surgery and patients' satisfaction rate for nursing care. Methods: Ninety-eight patients who attended Taizhou People's Hospital and underwent gynecological surgery between January 2021 and December 2021 were selected as subjects and divided into two groups according to a random number table, with 49 cases in each group. The control group was given conventional nursing care, and the experimental group received nursing intervention based on the G-Caprini scale. The rate of postoperative lower-limb deep-vein thrombosis in the two groups was compared, and the incidence of VTE and the level of nursing satisfaction in the two groups were statistically analyzed. Results: The incidence of postoperative VTE in each risk class of the G-Caprini scale was lower in the experimental group than in the control group, and the difference was statistically significant (P < 0.01). In the experimental group, 47 patients were very satisfied with the nursing care, 1 was satisfied, and 1 was dissatisfied, which meant the nursing satisfaction rate in the experimental group was 97.96 (48/49). In the control group, 40 patients were very satisfied with the nursing care, 2 were satisfied, 1 was basically satisfied, and 6 were dissatisfied; thus, the satisfaction rate for nursing care in the control group was 87.75%. The difference between the two groups was statistically significant (χ 2 = 19.657, p < 0.05). Conclusion: Nursing interventions based on the G-Caprini rating scale were significantly effective in preventing VTE in patients after gynecological surgery and resulted in higher levels of patient satisfaction in terms of nursing care.

6.
Sci Data ; 9(1): 286, 2022 06 09.
Artículo en Inglés | MEDLINE | ID: mdl-35680932

RESUMEN

The big-data use is becoming a standard practice in the neuroimaging field through data-sharing initiatives. It is important for the community to realize that such open science effort must protect personal, especially facial information when raw neuroimaging data are shared. An ideal tool for the face anonymization should not disturb subsequent brain tissue extraction and further morphological measurements. Using the high-resolution head images from magnetic resonance imaging (MRI) of 215 healthy Chinese, we discovered and validated a template effect on the face anonymization. Improved facial anonymization was achieved when the Chinese head templates but not the Western templates were applied to obscure the faces of Chinese brain images. This finding has critical implications for international brain imaging data-sharing. To facilitate the further investigation of potential culture-related impacts on and increase diversity of data-sharing for the human brain mapping, we released the 215 Chinese multi-modal MRI data into a database for imaging Chinese young brains, namely'I See your Brains (ISYB)', to the public via the Science Data Bank ( https://doi.org/10.11922/sciencedb.00740 ).


Asunto(s)
Mapeo Encefálico , Neuroimagen , Encéfalo/anatomía & histología , China , Humanos , Imagen por Resonancia Magnética
7.
Ying Yong Sheng Tai Xue Bao ; 33(5): 1363-1369, 2022 May.
Artículo en Chino | MEDLINE | ID: mdl-35730095

RESUMEN

In the semi-humid region, developing innovative water conservation urban green space design and facilitating urban greening projects from high water consumption to water conservation are hot topics in research and practice. Using the simulated rainfall method, we explored the water interception and collection functions and their influencing factors of six shrub species (Ligustrum ×vicaryi, Euonymus japonicas, Buxus sinica var. parvifolia, Photinia ×fraseri, Juniperus chinensis and Platycladus orientalis) in urban green space in the semi-humid region. The results showed that canopy interception and water harvesting were two stages in hydrological processes. The canopy interception of coniferous shrubs was high, while their stemflow was low. When the rainfall intensity increased, throughfall rates and stem-flow rates of all shrub species increased significantly, while the interception rate relatively decreased. The throughfall and stem-flow rates of broad-leaved shrubs were significantly higher than those of coniferous shrubs. The canopy interception was significantly lower in broad-leaved shrub species than in coniferous ones. At the center of canopy projection, the throughfall rate was the lowest. The leaf area index (LAI) and throughfall rate decreased gradually from the center of the canopy projection area. When the rainfall intensity was small, the throughfall rate at the center of canopy projection area was low, and thus the interception rate and the stem-flow rate were higher. When the rainfall intensity was more elevated, throughfall at the center of canopy projection area was large, and thus the interception rate and the stem-flow rate were low. With increasing rainfall intensity, the funnel-shaped water collection system tended to shrink due to the increases of throughfall rate at the edge of canopy. Rainfall intensity and LAI were the most critical factors affecting water harvesting function. Planting broad-leaved shrubs under the forest may be more effective in water harvesting than planting coniferous shrubs.


Asunto(s)
Lluvia , Tracheophyta , Bosques , Parques Recreativos , Árboles , Agua , Movimientos del Agua
8.
Research (Wash D C) ; 2022: 9783602, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35252873

RESUMEN

Unraveling the complexity of the lipidome requires the development of novel approaches to facilitate structural identification and characterization of lipid species with isomer-level discrimination. Ultraviolet photodissociation tandem mass spectrometry (UVPD MS/MS) is a promising tool for structure determination of lipids. The sensitivity of UVPD for lipid analysis however is limited mainly due to weak absorption of UV photons by a C=C. Herein, a C=C site-specific derivatization, the Paternò-Büchi (PB) reaction, was used to incorporate a chromophore to the C=C moiety in fatty acyls, leading to significantly improved UVPD efficiency and sensitivity for pinpointing C=C locations. The wavelength-dependent photodissociation of the PB products demonstrated 4-CF3-benzophenone as the best reagent for UVPD in terms of the efficiency of generating C=C diagnostic fragments and simplicity for C=C location assignments. We demonstrated the effectiveness of this approach for the shotgun profiling of C=C location isomers in different lipid classes from complex lipid extracts, highlighting its potential to advancing the identification of the C=C bond locations in unsaturated lipids.

9.
Fa Yi Xue Za Zhi ; 38(5): 573-578, 2022 Oct 25.
Artículo en Inglés, Chino | MEDLINE | ID: mdl-36727171

RESUMEN

OBJECTIVES: To analyze and predict the striking velocity range of stick blunt instruments in different populations, and to provide basic data for the biomechanical analysis of blunt force injuries in forensic identification. METHODS: Based on the Photron FASTCAM SA3 high-speed camera, Photron FASTCAM Viewer 4.0 and SPSS 26.0 software, the tester's maximum striking velocity of stick blunt instruments and related factors were calculated and analyzed, and inputed to the backpropagation (BP) neural network for training. The trained and verified BP neural network was used as the prediction model. RESULTS: A total of 180 cases were tested and 470 pieces of data were measured. The maximum striking velocity range was 11.30-35.99 m/s. Among them, there were 122 female data, the maximum striking velocity range was 11.63-29.14 m/s; there were 348 male data, the maximum striking velocity range was 20.11-35.99 m/s. The maximum striking velocity of stick blunt instruments increased with the increase of weight and height, but there was no obvious increase trend in the male group; the maximum striking velocity decreased with age, but there was no obvious downward trend in the female group. The maximum striking velocity of stick blunt instruments has no significant correlation with the material and strike posture. The root mean square error (RMSE), the mean absolute error (MAE) and the coefficient of determination (R2) of the prediction results by using BP neural network were 2.16, 1.63 and 0.92, respectively. CONCLUSIONS: The prediction model of BP neural network can meet the demand of predicting the maximum striking velocity of different populations.


Asunto(s)
Redes Neurales de la Computación , Heridas no Penetrantes , Masculino , Humanos , Femenino , Programas Informáticos , Medicina Legal
10.
J Pharm Anal ; 11(4): 499-504, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34513126

RESUMEN

Cordycepin, which has great immunomodulatory activities such as anticancer, antifungal, antivirus, antileukemia and lipid-lowering ones, is the secondary metabolite of Cordyceps militaris (C. militaris). Liquid submerged fermentation is the common cultivation process to produce cordycepin. To optimize the fermentation process and improve production, monitoring the cordycepin secretion in the fermentation is essential. The measurement based on chromatography-mass spectrometry methods is generally involved in the complex sample pretreatments and time-consuming separation, so more rapid and convenient methods are required. Matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS) is more attractive for faster and direct detection. Therefore, MALDI-MS detection combined with isotope-labeled internal standard was applied to the measurement of cordycepin content in the fermentation broth and mycelium. This method made accurate quantification of cordycepin in the range of 5-400 µg/mL with a relative standard deviation of 5.6%. The recovery rates of fermentation samples after the 1, 13, and 25 days were 90.15%, 94.27%, and 95.06%, respectively. The contents of cordycepin in the mycelium and fermentation broth were 136 mg/g and 148.39 mg/mL on the 20th culture day, respectively. The cordycepin secretion curve of the liquid fermentation of C. militaris was real-time traced over 25 days.

11.
Talanta ; 233: 122570, 2021 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-34215066

RESUMEN

Lipids differences between tumor and normal tissue have been proved to be of diagnostic and therapeutic significance. The research of lipidomics in tumor is more and more important. Mass spectrometry like matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS) can be more convenient and informative for lipids researching in biological and clinical researches. Most of malignant tumors like glioblastoma are characterized by incomplete differentiation, so differentiation therapy has made important progress in tumor treatment. Lipid profiles changes after therapy are worthy investigating. In our study, glioblastoma cell line U87-MG cells were treated by inducers of sodium phenylbutyrate (SPB) and all-trans retinoic acid (ATRA). The changes in lipids on cell membrane were profiled by MALDI-MS. The differentiation degree was assessed by cell proliferation, cell cycle, morphology and protein expression before MALDI-MS analysis. Comparing the inducer treated and untreated U87-MG cells, reduced proliferation rate, blocked cell cycle, benign nucleus morphology and changed expression of protein CD133 and glial fibrillary acidic protein (GFAP), were found after drug treatment. Moreover, the lipids of cell membrane presented distinguished differences in the drug treated cells. Most of the glycerophosphocholines (PC) with an increasing abundance are unsaturated PCs (PC (38:1), 816 m/z; PC (36:1), 788 m/z; PC (31:1), 725 m/z), and those decreasing are saturated PCs (PC (32:0), 734 m/z). These results provide the lipidomic differentiation which may be a significant guidance for evaluating the therapeutic effect of tumor therapy.


Asunto(s)
Glioblastoma , Preparaciones Farmacéuticas , Diferenciación Celular , Glioblastoma/tratamiento farmacológico , Humanos , Lipidómica , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción
12.
Neuroinformatics ; 19(3): 529-545, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33409718

RESUMEN

Rhythms of the brain are generated by neural oscillations across multiple frequencies. These oscillations can be decomposed into distinct frequency intervals associated with specific physiological processes. In practice, the number and ranges of decodable frequency intervals are determined by sampling parameters, often ignored by researchers. To improve the situation, we report on an open toolbox with a graphical user interface for decoding rhythms of the brain system (DREAM). We provide worked examples of DREAM to investigate frequency-specific performance of both neural (spontaneous brain activity) and neurobehavioral (in-scanner head motion) oscillations. DREAM decoded the head motion oscillations and uncovered that younger children moved their heads more than older children across all five frequency intervals whereas boys moved more than girls in the age of 7 to 9 years. It is interesting that the higher frequency bands contain more head movements, and showed stronger age-motion associations but weaker sex-motion interactions. Using data from the Human Connectome Project, DREAM mapped the amplitude of these neural oscillations into multiple frequency bands and evaluated their test-retest reliability. The resting-state brain ranks its spontaneous oscillation's amplitudes spatially from high in ventral-temporal areas to low in ventral-occipital areas when the frequency band increased from low to high, while those in part of parietal and ventral frontal regions are reversed. The higher frequency bands exhibited more reliable amplitude measurements, implying more inter-individual variability of the amplitudes for the higher frequency bands. In summary, DREAM adds a reliable and valid tool to mapping human brain function from a multiple-frequency window into brain waves.


Asunto(s)
Ondas Encefálicas , Conectoma , Adolescente , Encéfalo , Mapeo Encefálico , Niño , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Reproducibilidad de los Resultados
13.
Angew Chem Int Ed Engl ; 59(47): 21216-21223, 2020 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-32767516

RESUMEN

Photoassisted steam reforming and dry (CO2 ) reforming of methane (SRM and DRM) at room temperature with high syngas selectivity have been achieved in the gas-phase catalysis for the first time. The catalysts used are bimetallic rhodium-vanadium oxide cluster anions of Rh2 VO1-3 - . Both the oxidation of methane and reduction of H2 O/CO2 can take place efficiently in the dark while the pivotal step to govern syngas selectivity is photo-excitation of the reaction intermediates Rh2 VO2,3 CH2 - to specific electronically excited states that can selectively produce CO and H2 . Electronic excitation over Rh2 VO2,3 CH2 - to control the syngas selectivity is further confirmed from the comparison with the thermal excitation of Rh2 VO2,3 CH2 - , which leads to diversity of products. The atomic-level mechanism obtained from the well-controlled cluster reactions provides insight into the process of selective syngas production from the photocatalytic SRM and DRM reactions over supported metal oxide catalysts.

14.
J Am Chem Soc ; 142(7): 3499-3505, 2020 02 19.
Artículo en Inglés | MEDLINE | ID: mdl-31994883

RESUMEN

The [2 + 2] photocycloaddition of alkenes and carbonyls is of fundamental interest and practical importance, as this process is extensively involved in oxetane-ring constructions. Although individual carbonyl group or alkene moiety has been utilized as photoactive species for oxetane formations upon ultraviolet photoexcitation, direct excitation of the entire noncovalent complex involving alkene and carbonyl substrates to achieve [2 + 2] photocycloadditions is rarely addressed. Herein, complexes with noncovalent interactions between benzophenone and C═C bonds in unsaturated lipids have been successfully characterized, and for the first time a [2 + 2] cycloaddition leading to the formation of oxetanes has been identified under visible-light irradiation. The mechanism of this reaction is distinctly different from the well-studied Paternò-Büchi reaction. The entire complexes characterized as dimeric proton-bonded alkene and carbonyl substrates can be excited under visible light, leading to electron transfer from the alkene moiety in fatty acyls to the carbonyl group within the complex. These results provide new insight into utilizing noncovalent complexes for the synthesis of oxetanes in which the excitation wavelength becomes independent of each individual substrate.


Asunto(s)
Benzofenonas/química , Ácidos Grasos Insaturados/química , Reacción de Cicloadición , Éteres Cíclicos/síntesis química , Modelos Moleculares , Procesos Fotoquímicos , Teoría Cuántica , Espectrometría de Masa por Ionización de Electrospray
16.
Front Microbiol ; 10: 2176, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31616396

RESUMEN

The impact of gut microbiota and its metabolites on fat metabolism have been widely reported in human and animals. However, the critical mediators and the signal transductions are not well demonstrated. As ovipara, chicken represents a specific case in lipid metabolism that liver is the main site of lipid synthesis. The aim of this study is to elucidate the linkage of gut microbiota and fat synthesis in broiler chickens. The broilers were subjected to dietary treatments of combined probiotics (Animal bifidobacterium: 4 × 108 cfu/kg; Lactobacillus plantarum: 2 × 108 cfu/kg; Enterococcus faecalis: 2 × 108 cfu/kg; Clostridium butyrate: 2 × 108 cfu/kg, PB) and guar gum (1 g/kg, GG), respectively. Results showed that dietary supplementation of PB and GG changed the cecal microbiota diversity, altered short chain fatty acids (SCFAs) contents, and suppressed lipogenesis. In intestinal epithelial cells (IECs), SCFAs (acetate, propionate, and butyrate) up-regulated the expression of glucagon-like peptide-1 (GLP-1) via mitogen-activated protein kinase (MAPK) pathways, mainly via the phospho - extracellular regulated protein kinase (ERK) and phospho-p38 mitogen activated protein kinase (p38 MAPK) pathways. GLP-1 suppressed lipid accumulation in primary hepatocytes with the involvement of (AMP)-activated protein kinase/Acetyl CoA carboxylase (AMPK/ACC) signaling. In conclusion, the result suggests that SCFAs-induced GLP-1 secretion via MAPK pathway, which links the regulation of gut microbiota on hepatic lipogenesis in chickens.

17.
Talanta ; 191: 67-73, 2019 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-30262100

RESUMEN

Developing a bio-functional model in vitro to study cancer resistance, which is a big challenge for clinical cancer therapy, is of great interest. Such reliable model requires appropriate drug diffusion kinetics simulation and a microenvironment that allows cell-cell and cell-matrix interactions. In this work, a special hydrogel-based three-dimensional (3D) microfluidic chip was constructed to simulate tumour-vascular microenvironment. The self-healing hydrogel supports long-time cell survival and proliferation, effective cellular metabolism of cancer drugs and cell-cell interaction between different types of cells. In the effective near-physiological tumour-vascular microenvironment, the endothelial and fibroblast cells are spread on different sides of a porous membrane, while sensitive and resistant breast tumour cells are separately cultured in the dynamic hydrogel consisting of glycol chitosan and telechelic difunctional poly (ethylene glycol) in the upper chambers. Nutrients and drugs are introduced through the bottom channel and diffuse into the cancer cells. Doxorubicin molecules pass first through blood vessel endothelial cells and act on the tumour cells surrounded by fibroblasts. Tumour cells respond differently to drug when they are cultured in the microenvironment. Sensitive breast tumour cells have a 47% increase in viability than those cultured without fibroblasts and endothelial cells. Both sensitive and resistant tumour cells can be analysed under the same chemical environment. This work represents a multi-functional in vitro platform that allows near-physiological simulation, effective drug metabolism and cellular response to extracellular stimuli and has great potential to make drug discovery speedy and precise.


Asunto(s)
Biomimética/instrumentación , Resistencia a Antineoplásicos , Hidrogeles/química , Dispositivos Laboratorio en un Chip , Microambiente Tumoral/efectos de los fármacos , Células 3T3 , Animales , Vasos Sanguíneos/metabolismo , Matriz Extracelular/metabolismo , Estudios de Factibilidad , Humanos , Células MCF-7 , Ratones , Permeabilidad , Polietilenglicoles/química
18.
Anal Chim Acta ; 1027: 76-82, 2018 Oct 16.
Artículo en Inglés | MEDLINE | ID: mdl-29866272

RESUMEN

Herein, a chemiluminescence assay with dual signal amplification has been developed based on multi-DNAzymes-functionalized gold nanoparticles (AuNPs) using in situ rolling circle amplification (RCA) for ultrasensitive detection of thrombin on microchip. In this assay, AuNPs was functionalized by aptamer and multi-RCA primer for amplification, and thrombin was sandwiched between the aptamer modified on the microchannel and the aptamer linked AuNP. The further amplification was realized by in situ RCA to expand specific oligonucleotides chains on the AuNPs and produce particular multi-DNAzymes. Enhanced chemiluminescence signal was achieved by the catalytic effect of DNAzymes in the luminol-H2O2 system. The sensitivity of detection was greatly improved by the dual amplification of multi-RCA primer modified AuNPs, and RCA. The whole strategy was applied for ultrasensitive and specific detection of thrombin. The chemiluminesce assay of thrombin performed a good linear range of 1-25 pM and the limit of detection was as low as 0.55 pM. The successful determination of thrombin in real human serum sample indicated a great potential in clinical study.


Asunto(s)
Aptámeros de Nucleótidos/química , Oro/química , Mediciones Luminiscentes/métodos , Nanopartículas del Metal/química , Procedimientos Analíticos en Microchip , Trombina/análisis , Humanos , Peróxido de Hidrógeno/química , Límite de Detección , Luminol/química , Técnicas de Amplificación de Ácido Nucleico , Trombina/química
19.
Phys Chem Chem Phys ; 20(7): 4641-4645, 2018 Feb 14.
Artículo en Inglés | MEDLINE | ID: mdl-29379936

RESUMEN

Investigation on the reactivity of atomic clusters represents an important approach to discover new species to activate and transform methane, the most stable alkane molecule. While a few types of transition metal species have been found to be capable of cleaving the C-H bond of methane, methane activation by the transition metal boride species has not been explored yet. This study reports that vanadium boride cluster cations VBn+ (n = 3-6) can dehydrogenate methane under thermal collision conditions. The mechanistic details of the efficient reactions have been elucidated by quantum chemistry calculations on the VB3+ reaction system. Compared to the non-polar bare B3 cluster, the B3 moiety in VB3+ can be polarized by the V+ cation and thus its reactivity toward methane can be much enhanced. This study provides new insights into the rational design of boron-based catalysts for methane activation.

20.
Angew Chem Int Ed Engl ; 57(10): 2662-2666, 2018 03 01.
Artículo en Inglés | MEDLINE | ID: mdl-29359384

RESUMEN

The underlying mechanism for non-oxidative methane aromatization remains controversial owing to the lack of experimental evidence for the formation of the first C-C bond. For the first time, the elementary reaction of methane with atomic clusters (FeC3- ) under high-temperature conditions to produce C-C coupling products has been characterized by mass spectrometry. With the elevation of temperature from 300 K to 610 K, the production of acetylene, the important intermediate proposed in a monofunctional mechanism of methane aromatization, was significantly enhanced, which can be well-rationalized by quantum chemistry calculations. This study narrows the gap between gas-phase and condensed-phase studies on methane conversion and suggests that the monofunctional mechanism probably operates in non-oxidative methane aromatization.

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