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1.
Cells ; 13(3)2024 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-38334611

RESUMEN

Isocitrate Dehydrogenase-1 (IDH1) is commonly mutated in lower-grade diffuse gliomas. The IDH1R132H mutation is an important diagnostic tool for tumor diagnosis and prognosis; however, its role in glioma development, and its impact on response to therapy, is not fully understood. We developed a murine model of proneural IDH1R132H-mutated glioma that shows elevated production of 2-hydroxyglutarate (2-HG) and increased trimethylation of lysine residue K27 on histone H3 (H3K27me3) compared to IDH1 wild-type tumors. We found that using Tazemetostat to inhibit the methyltransferase for H3K27, Enhancer of Zeste 2 (EZH2), reduced H3K27me3 levels and increased acetylation on H3K27. We also found that, although the histone deacetylase inhibitor (HDACi) Panobinostat was less cytotoxic in IDH1R132H-mutated cells (either isolated from murine glioma or oligodendrocyte progenitor cells infected in vitro with a retrovirus expressing IDH1R132H) compared to IDH1-wild-type cells, combination treatment with Tazemetostat is synergistic in both mutant and wild-type models. These findings indicate a novel therapeutic strategy for IDH1-mutated gliomas that targets the specific epigenetic alteration in these tumors.


Asunto(s)
Compuestos de Bifenilo , Glioma , Inhibidores de Histona Desacetilasas , Morfolinas , Piridonas , Animales , Ratones , Inhibidores de Histona Desacetilasas/farmacología , Inhibidores de Histona Desacetilasas/uso terapéutico , Histonas/genética , Glioma/tratamiento farmacológico , Glioma/genética , Glioma/patología , Benzamidas
2.
Microbiol Res ; 282: 127654, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38417203

RESUMEN

Abdominal obesity (AO), characterized by the excessive abdominal fat accumulation, has emerged as a significant public health concern due to its metabolic complications and escalating prevalence worldwide, posing a more pronounced threat to human health than general obesity. While certain studies have indicated that intestinal flora contributed to diet-induced general obesity, the precise involvement of gut microbiota in the development of AO, specifically the accumulation of abdominal fat, remains inadequately explored. In this study, the 16 S rDNA sequencing was employed to analyze gut flora alterations, and the intestinal microbiota dysbiosis characterized by a vanishing decline of Akkermansia was found in the AO group. Along with notable gut microbiota changes, the intestinal mucosal barrier damage and metabolic inflammation were detected, which collectively promoted metabolic dysregulation in AO. Furthermore, the metabolic inflammation and AO were ameliorated after the intestinal microbiota depletion with antibiotics (ABX) drinking, underscoring a significant involvement of gut microbiota dysbiosis in the progression of AO. More importantly, our findings demonstrated that the transplantation of healthy intestinal flora successfully reversed the gut microbiota dysbiosis, particularly the decline of Akkermansia in the AO group. The gut flora reshaping has led to the repair of gut barrier damage and mitigation of metabolic inflammation, which ultimately ameliorated abdominal fat deposition. Our study established the role of interactions between gut flora, mucus barrier, and metabolic inflammation in the development of AO, thereby offering a theoretical foundation for the clinical application of fecal microbiota transplantation (FMT) as a treatment for AO.


Asunto(s)
Trasplante de Microbiota Fecal , Microbiota , Ratones , Humanos , Animales , Obesidad Abdominal , Disbiosis/terapia , Obesidad/tratamiento farmacológico , Obesidad/metabolismo , Inflamación , Ratones Endogámicos C57BL
3.
Phys Rev E ; 109(1-1): 014108, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38366460

RESUMEN

Predicting the ice melting point using molecular dynamics (MD) simulations is nontrivial due to uncertainty associated with the stochastic nature of the simulation and effect of finite domain sizes on the simulated ice-water phase transition. We developed a method based on the percolation theory to make use of the finite size effects to allow determination of a unique critical phase transition temperature as the melting point. The method involves construction of melting/freezing probability curves from multiple simulations with varying temperatures for different domain sizes. While the domain sizes affect the apparent melting/freezing probability and hence generate different curves with a wider probability distribution for a smaller size, the intersection of these curves is unique and locates the melting point. Based on MD simulations using the Tip4p/Ice water model, we tested and demonstrated the effectiveness of this method in locating the critical ice-water phase transition at a melting temperature of 268.78 K. Our analysis also showed that the apparent melting probability at this critical point is ∼0.69, not 0.5 assumed in the ad hoc method used previously. Our method, making no assumption about the system size, may provide a generic framework for analyzing phase transitions influenced by the finite size effects in MD simulations.

4.
Plant Phenomics ; 5: 0054, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37213546

RESUMEN

Plant diseases threaten global food security by reducing crop yield; thus, diagnosing plant diseases is critical to agricultural production. Artificial intelligence technologies gradually replace traditional plant disease diagnosis methods due to their time-consuming, costly, inefficient, and subjective disadvantages. As a mainstream AI method, deep learning has substantially improved plant disease detection and diagnosis for precision agriculture. In the meantime, most of the existing plant disease diagnosis methods usually adopt a pre-trained deep learning model to support diagnosing diseased leaves. However, the commonly used pre-trained models are from the computer vision dataset, not the botany dataset, which barely provides the pre-trained models sufficient domain knowledge about plant disease. Furthermore, this pre-trained way makes the final diagnosis model more difficult to distinguish between different plant diseases and lowers the diagnostic precision. To address this issue, we propose a series of commonly used pre-trained models based on plant disease images to promote the performance of disease diagnosis. In addition, we have experimented with the plant disease pre-trained model on plant disease diagnosis tasks such as plant disease identification, plant disease detection, plant disease segmentation, and other subtasks. The extended experiments prove that the plant disease pre-trained model can achieve higher accuracy than the existing pre-trained model with less training time, thereby supporting the better diagnosis of plant diseases. In addition, our pre-trained models will be open-sourced at https://pd.samlab.cn/ and Zenodo platform https://doi.org/10.5281/zenodo.7856293.

5.
Plant J ; 114(4): 767-782, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36883481

RESUMEN

Plant diseases worsen the threat of food shortage with the growing global population, and disease recognition is the basis for the effective prevention and control of plant diseases. Deep learning has made significant breakthroughs in the field of plant disease recognition. Compared with traditional deep learning, meta-learning can still maintain more than 90% accuracy in disease recognition with small samples. However, there is no comprehensive review on the application of meta-learning in plant disease recognition. Here, we mainly summarize the functions, advantages, and limitations of meta-learning research methods and their applications for plant disease recognition with a few data scenarios. Finally, we outline several research avenues for utilizing current and future meta-learning in plant science. This review may help plant science researchers obtain faster, more accurate, and more credible solutions through deep learning with fewer labeled samples.


Asunto(s)
Enfermedades de las Plantas , Aprendizaje Profundo
6.
Langmuir ; 39(12): 4507-4517, 2023 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-36930807

RESUMEN

The equilibrium contact angle depends on both the chemistry of the two fluids and solid base and the microstructure on the solid surface. Actual surface of the pore wall in porous media is typically rough and curved, which has not been well-considered in related applications. This work uses a free interfacial energy minimization approach to theoretically derive the equilibrium contact angle on two specific surface structures on flat surfaces and extends the derivation considering the surface curvatures in porous media. Results reveal that the equilibrium contact angle is not dependent on the curvature of spherical surfaces, and we further prove that this conclusion applies to any point along the apparent common line at solid surfaces with any arbitrary curvature. The fundamental physics is the local mechanical balance of a composite contact among three interfacial tensions. Furthermore, the contacting mode can shift from non-wetting to wetting when the pressure difference between two fluids exceeds the entry pressure of the microstructures, which should be considered in relative dynamic scenarios such as rain droplet impact and fluid displacement in porous media. Note that these conclusions are from pure theoretical analysis based on idealistic assumptions, and real circumstances may deviate from these assumptions.

7.
Front Psychol ; 14: 1107935, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36959995

RESUMEN

Purpose: This study investigated gender differences in behavioral inhibitory control among college students under acute stress state by using event-related potential technique. Methods: Acute stress was evoked in 41 college students (22 males and 19 females) using the Trier Social Stress paradigm, and the neutral state was matched using out-of-speech reading, with subjects completing a two-choice Oddball task in each of the two states. In combination with the ERP technique, the area under the stress curve, reaction time, number of errors, and the difference waves between the two stimulus conditions in the frontal-central region N2 wave amplitude and the parietal-central region P3 wave amplitude were compared between the two groups of subjects in the stressful and neutral state. Results: The results revealed that the area under the stress curve was larger under the stress condition compared to the neutral condition, and the area under the stress curve was larger in females than in males. Behavioral results showed no statistically significant differences in reaction time and number of errors between the two genders in the acute stress condition. The ERP results showed that the wave amplitudes of N2 and P3 decreased significantly in both genders in the acute stress state. The decrease in N2 amplitude was greater in females during the transition from neutral to stressful condition, while the difference in P3 amplitude was not statistically significant in both genders. Conclusion: The findings suggest that evoked acute stress can promote behavioral inhibitory control in both genders and that females are more sensitive to acute stress state.

8.
Neural Netw ; 162: 502-515, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36972650

RESUMEN

Multi-view stereo reconstruction aims to construct 3D scenes from multiple 2D images. In recent years, learning-based multi-view stereo methods have achieved significant results in depth estimation for multi-view stereo reconstruction. However, the current popular multi-stage processing method cannot solve the low-efficiency problem satisfactorily owing to the use of 3D convolution and still involves significant amounts of calculation. Therefore, to further balance the efficiency and generalization performance, this study proposed a multi-scale iterative probability estimation with refinement, which is a highly efficient method for multi-view stereo reconstruction. It comprises three main modules: 1) a high-precision probability estimator, dilated-LSTM that encodes the pixel probability distribution of depth in the hidden state, 2) an efficient interactive multi-scale update module that fully integrates multi-scale information and improves parallelism by interacting information between adjacent scales, and 3) a Pi-error Refinement module that converts the depth error between views into a grayscale error map and refines the edges of objects in the depth map. Simultaneously, we introduced a large amount of high-frequency information to ensure the accuracy of the refined edges. Among the most efficient methods (e.g., runtime and memory), the proposed method achieved the best generalization on the Tanks & Temples benchmarks. Additionally, the performance of the Miper-MVS was highly competitive in DTU benchmark. Our code is available at https://github.com/zhz120/Miper-MVS.


Asunto(s)
Benchmarking , Generalización Psicológica , Aprendizaje , Probabilidad
9.
Polymers (Basel) ; 15(4)2023 Feb 05.
Artículo en Inglés | MEDLINE | ID: mdl-36850086

RESUMEN

Polypropylene (PP)/sepiolite nanocomposites were prepared using the melt blending technique. The effects of nano-sepiolite content on the mechanical property, thermal property, crystallinity, morphology and rheological property of PP/sepiolite nanocomposites were investigated. The organic modified sepiolites (OSep) were dispersed evenly in PP matrix after surface treatment. The addition of OSep improved the storage modulus and thermal stability, showing a strong interaction between OSep and PP matrix. With the increase of OSep content, the fluidity of PP/OSep composites first increased due to the lubrication of surface modifiers and then decreased due to the interaction between OSep and PP. The size of the toughening agent elastomer first increased and then decreased, and the impact notched strength of PP/Osep composites first decreased and then increased. The loading of OSep also reduced the crystallinity and shrinkage rate of PP. PP/OSep nanocomposites have potential applications in high-performance automotive lightweight materials.

10.
Opt Express ; 31(4): 6514-6528, 2023 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-36823905

RESUMEN

Light detection and ranging (lidar) is widely accepted as an indispensable sensor for autonomous vehicles. There are two fundamental challenges in a lidar system: optical beam steering technique and ranging method. Optical phased array (OPA) is considered as one of the most promising beam steering schemes due to its solid state, compact size, and high reliability. As for ranging method, time-of-flight and frequency-modulate continuous-wave (FMCW) are commonly utilized in numerous research. However, they are impractical to commercial OPA lidar due to either requiring excessive optical power or the poor stability, high complexity, and high insertion loss of the FMCW source. As a result, the development of OPA lidars is significantly hindered by the lack of a feasible ranging method. In this paper, we present a phase-modulated continuous-wave (PhMCW) ranging method with excellent ranging accuracy and precision. Ranging error as low as 0.1 cm and precision on the order of 3.5 cm are achieved. In addition, theoretical and experimental study on simultaneous velocity measurement is carried out and velocity error as low as 0.15 cm/s is obtained. Finally, we develop a proof-of-concept OPA-PhMCW lidar and obtain a point cloud with excellent fidelity. Our work paves a novel approach to solid-state, cost-effective and high-performance OPA lidars.

11.
Urol J ; 20(2): 96-101, 2023 Feb 27.
Artículo en Inglés | MEDLINE | ID: mdl-36609817

RESUMEN

PURPOSE: To investigate temperature changes around the fibres of the super pulse thulium fibre laser (SP-TFL) during in vitro lithotripsy. MATERIALS AND METHODS: Stones were placed in the in vitro model. The laser was continuously excited for 180 s; the probe was positioned 5 mm around the fibre; the laser power was set at 10, 15, 20, 25, and 30 W; and the irrigation rate was set at 0, 15, 25, 35 ml/min, using a domestic SP-TFL. The temperature variations around the fibre under different power settings and different irrigation rates were compared. RESULTS: Without irrigation, the temperature around the fibre rapidly reached the safety threshold of 43℃ at 24 s. At irrigation rate 15 ml/min and laser power <15 W, the temperature around the fibre was <43℃. Once the laser power increased to ≥20 W, the temperature around the fibre increased to >43℃ at its lowest plateau. At irrigation rate 25 ml/min and laser power ≤25 W, the temperature around the fibre was <43℃. At irrigation rate 35 ml/min and laser power <30 W, the fibre temperature was <43℃. When laser power was ≥30 W, the fibre temperature was >43℃. CONCLUSION: In extracorporeal ureteroscope SP-TFL lithotripsy, when the laser power is ≤15 W, ≤25 W, and ≤30 W, the irrigation rate should be maintained at ≥15 ml/min, ≥25 ml/min, and ≥35 ml/min, respectively.


Asunto(s)
Láseres de Estado Sólido , Litotripsia por Láser , Humanos , Temperatura , Tulio , Ureteroscopios
12.
Sensors (Basel) ; 22(19)2022 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-36236537

RESUMEN

A film bulk acoustic resonator (FBAR), based on a polymer air cavity, is presented. The polymer reflective layer on the polymer air cavity can serve both as the reflective layer and the function layer for inducing the high-order mode resonance. With the aluminum nitride as the piezoelectric layer, the resonance frequency of the FBAR can reach 6.360 GHz, based on the finite element method. The product of the corresponding frequency and the quality factor, f × Q is more than 2 × 1013. This design model provides a good solution for the high-frequency filters and high-sensitivity sensor designs.

13.
Sensors (Basel) ; 22(17)2022 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-36080938

RESUMEN

A high-frequency surface acoustic wave (SAW) resonator, based on sandwiched interdigital transducer (IDT), is presented. The resonator has the structure of diamond/AlN/IDT/AlN/diamond, with Si as the substrate. The results show that its phase velocity and electromechanical coupling coefficient are both significantly improved, compared with that of the traditional interdigital transduce-free surface structure. The M2 mode of the sandwiched structure can excite an operation frequency up to 6.15 GHz, with an electromechanical coupling coefficient of 5.53%, phase velocity of 12,470 m/s, and temperature coefficient of frequency of -6.3 ppm/°C. This structure provides a new ideal for the design of high-performance and high-frequency SAW devices.

14.
Front Oncol ; 12: 849368, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35387122

RESUMEN

Objectives: Upper gastrointestinal (G.I.) cancer screening has been conducted in China for decades. However, the economic burden for treatment "intensively" occurred in advance due to screening in resource-limited communities remain unclear. Methods: We compared the treatment costs for upper G.I. cancers from the screening and control arms of a population-based randomized trial in a high-risk area for esophageal cancer (EC) in China based on claims data from the health insurance system in the local area which included whole population coverage. Results: The average out-of-pocket cost per treatment of EC in the screening arm was lower than that in the control arm ($5,972 vs. $7,557). This difference was a consequence of down-staging from screening which resulted in lower cost therapy for earlier stage cancers. Moreover, this result is similar for cardial and non-cardial gastric cancer in the two study arms ($7,933 vs. $10,605). However, three times as many (103 vs. 36) families in the screening arm suffered catastrophic health expenditure for all cancer types. The overall treatment cost for all EC patients in the screening arm ($1,045,119) was 2.44 times that in the control arm ($428,292), and the ratio for cardial and non-cardial gastric cancer was 1.12 ($393,261 vs. $351,557). Conclusion: Cancer treatment secondary to screening may triple the likelihood of catastrophic patient medical expenditure, and sharply increase the economic pressure on the local community, particularly for cancer types which are of high prevalence. Financial support for patients and the health insurance system should be taken into consideration when planning budgets for cancer screening programs in communities which are resource-limited.

15.
Sci Rep ; 12(1): 3471, 2022 03 02.
Artículo en Inglés | MEDLINE | ID: mdl-35236868

RESUMEN

Both intra-pore hydrate morphology and inter-pore hydrate distribution influence the physical properties of hydrate-bearing sediments, yet there has been no pore-scale observations of hydrate habit under pressure in preserved pressure core samples so far. We present for the first time a pore-scale micro-CT study of natural hydrate-bearing cores that were acquired from Green Canyon Block 955 in UT-GOM2-1 Expedition and preserved within hydrate pressure-temperature stability conditions throughout sub-sampling and imaging processes. Measured hydrate saturation in the sub-samples, taken from units expected to have in-situ saturation of 80% or more, ranges from 3 ± 1% to 56 ± 11% as interpreted from micro-CT images. Pore-scale observations of gas hydrate in the sub-samples suggest that hydrate in silty sediments at the Gulf of Mexico is pore-invasive rather than particle displacive, and hydrate particles in these natural water-saturated samples are pore-filling with no evidence of grain-coating. Hydrate can form a connected 3D network and provide mechanical support for the sediments even without cementation. The technical breakthrough to directly visualize particle-level hydrate pore habits in natural sediments reported here sheds light on future investigations of pressure- and temperature-sensitive processes including hydrate-bearing sediments, dissolved gases, and other biochemical processes in the deep-sea environment.


Asunto(s)
Sedimentos Geológicos , Metano , Gases/química , Sedimentos Geológicos/química , Metano/química , Temperatura , Microtomografía por Rayos X
16.
Opt Express ; 30(3): 3379-3387, 2022 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-35209597

RESUMEN

Ultrafast laser micromachining of crystalline silicon carbide (SiC) has great perspectives in aerospace industry and integrated circuit technique. In this report, we present a study of femtosecond laser nanostructuring on the surface of an n-type 4H-SiC single crystal. Except for uniform nanogratings, new types of large-area periodic structures including nanoparticle array and nanoparticle-nanograting hybrid structures were induced on the surface of 4H-SiC by scanning irradiation. The effects of pulse energy, scan speed, and the polarization direction on the morphology and periodicity of nanogratings were systematically explored. The proper parameter window for nanograting formation in pulse energy-scan speed landscape is depicted. Both the uniformity and the periodicity of the induced nanogratings are polarization dependent. A planar light attenuator for linear polarized light was demonstrated by aligning the nanogratings. The transition between different large-area periodic structures is achieved by simultaneous control of pulse energy and scan interval using a cross scan strategy. These results are expected to open up an avenue to create and manipulate periodic nanostructures on SiC crystals for photonic applications.

17.
PLoS One ; 16(8): e0255048, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34351960

RESUMEN

MTS-810 material testing machine and acoustic emission signal analyzer were adopted to explore the mechanical behavior of concrete beams broken by the static load and the nonlinear cumulative damage law of concrete beams broken by fatigue bending from single-stage loading. Then, by introducing the Ramesh Talreja's Damage Criterion, the damage rule of single-stage loading was extended to the damage accumulation rule under multi-stage loading, and the results were verified by the results of two-stage and three-stage fatigue loading tests. Two main conclusions are achieved: first, affected by four-point bending load, the fatigue life of the concrete specimen is in line with the law of the two-parameter Weibull distribution, namely the higher the stress level is, the shorter the fatigue life is. Second, an obvious nonlinear relationship was discovered in the damage of concrete. The model deduced in this paper and the Palmgren-Miner linear damage accumulation model were adopted to compare the test results of flexural fatigue under single, two and three stage loads. The calculation results of this model were more reliable.


Asunto(s)
Materiales de Construcción , Modelos Teóricos , Estrés Mecánico , Acústica , Análisis de Regresión
18.
Opt Express ; 29(7): 10265-10274, 2021 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-33820166

RESUMEN

Manipulation of femtosecond laser induced microstructures in glass by tuning the laser polarization has great potential in optics. Here we report two different polarization-dependent microstructures and their evolution with pulse repetition rate in an aluminosilicate glass induced by femtosecond laser irradiation. A V-shaped crack oriented parallel to the laser polarization plane is induced at the bottom of modified regions by pulses operated at 200 kHz, 1030 nm, and 300 fs. Further increasing the pulse repetition rate to 500 kHz leads to the formation of a dumbbell-shaped structure, which is elongated perpendicularly to the laser polarization, at the top of the modified region. The size of the coloration area and the dumbbell-shaped structure can be controlled by tuning the pulse duration. Further investigation indicates that higher numerical apertures are in favor of the presence of the polarization effects in femtosecond laser irradiation. The possible mechanism responsible for the formation of the two microstructures is discussed. These results could be helpful for understanding of ultrafast laser interaction with glass.

19.
EClinicalMedicine ; 33: 100756, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-33718848

RESUMEN

BACKGROUND: We aimed to establish a new approach for surveillance of cancer prevalence and survival in China, based on the Medical-Insurance-System-based Cancer Surveillance System (MIS-CASS). METHODS: We constructed a standard procedure for data collection, cleaning, processing, linkage, verification, analysis, and estimation of cancer prevalence and survival (including both actual observations and model estimates) by conjoint use of medical insurance claims data and all-cause death surveillance data. As a proof-of-principle study, we evaluated the performance of this surveillance approach by estimating the latest prevalence and survival for upper gastrointestinal cancers in Hua County, a high-risk region for oesophageal cancer in China. FINDINGS: In Hua County, the age-standardised relative 5-year survival was 39·2% (male: 36·8%; female: 43·6%) for oesophageal cancer and 33·3% (male: 29·6%; female: 43·4%) for stomach cancer. For oesophageal cancer, better survival was observed in patients of 45-64 years compared with national average estimates, and women of <75 years had better survival than men. The 5-year prevalence rate in Hua County was 99·8/100,000 (male: 105·9/100,000; female: 93·3/100,000) for oesophageal cancer and 41·5/100,000 (male: 57·4/100,000; female: 24·5/100,000) for stomach cancer. For both of these cancers, the prevalence burden peaked at 65-79 years. The model estimates for survival and prevalence were close to the observations in real investigation, with a relative difference of less than 4·5%. INTERPRETATION: This novel approach allows accurate estimation of cancer prevalence and survival with a short delay, which has great potential for regular use in general Chinese populations, especially those not covered by cancer registries. FUNDING: The National Key R&D Program of China (2016YFC0901404), the National Science & Technology Fundamental Resources Investigation Program of China (2019FY101102), the National Natural Science Foundation of China (82073626), the Taikang Yicai Public Health and Epidemic Control Fund (TKYC-GW-2020), the Beijing-Tianjin-Hebei Basic Research Cooperation Project (J200016), and the Digestive Medical Coordinated Development Center of Beijing Hospitals Authority (XXZ0204).

20.
Spectrochim Acta A Mol Biomol Spectrosc ; 239: 118546, 2020 Oct 05.
Artículo en Inglés | MEDLINE | ID: mdl-32505107

RESUMEN

In this paper, a label-free fluorescence nanoprobe is constructed based on poly(thymine) single strand DNA-templated Copper nanocluster (denote as: T-CuNCs) for the detection of hydrogen peroxide. In the assay, the fluorescent T-CuNCs will generate though the reaction of Cu2+, poly(thymine) and sodium ascorbate. However, the hydroxyl radical (.OH) will generated in the presence of H2O2, which is able to induced the oxidative lesions of poly(thymine) single chain DNA and lead to the poly(thymine) being splitted into shorter or single oligonucleotide fragments and lose the ability to template the fluorescent T-CuNCs again. Therefore, H2O2 can be detected by monitoring the fluorescence strength change of T-CuNCs. The experimental results show that the fluorescence intensity change of T-CuNCs has fantastic linearity versus H2O2 concentration in the range of 1-30 µM (R2 = 0.9947) and 30-80 µM (R2 = 0.9972) with the limit of detection (LOD) as low as 0.5 µM (S/N = 3). More important, the fluorescent nanoprobe was also successfully utilized on the detection of H2O2 in serum samples. Therefore, a label-free, costless and effective fluorescence method has been established for the detection of H2O2, the intrinsic properties of the nanoprobe endow its more potential applications in chemical and biological study.


Asunto(s)
Cobre , Nanopartículas del Metal , ADN , Colorantes Fluorescentes , Peróxido de Hidrógeno , Espectrometría de Fluorescencia , Timina
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