Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 7 de 7
Filtrar
Más filtros

Banco de datos
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
Neurochem Res ; 46(9): 2376-2386, 2021 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-34146195

RESUMEN

Our study aimed to explore the function and mechanism of action of long noncoding RNA (lncRNA) SRY-Box 21 antisense RNA 1 (SOX21-AS1) in amyloid beta25-35 (Aß25-35)-induced neuronal damage. To induce neuronal damage, neuronal cells and differentiated IMR-32 neuroblastoma cells were challenged by Aß25-35. SOX21-AS1 and miR-132 quantities were detected by quantitative reverse transcription polymerase chain reaction. Cell damage was evaluated by detecting the changes of cell viability, apoptosis, and oxidative stress. Cell viability was measured using cell counting kit-8. Cell apoptosis was evaluated by flow cytometry and caspase-3 activity. The oxidative stress was analyzed by reactive oxygen species level. The expression of proteins associated with the phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) pathway was examined by western blot. SOX21-AS1 abundance was up-regulated in Aß25-35-challenged neuronal cells. Silencing of SOX21-AS1 attenuated Aß25-35-induced viability reduction and promotion of apoptosis and oxidative stress, suggesting that silencing of SOX21-AS1 repressed Aß25-35-induced neuronal damage. miR-132 quantity was reduced in Aß25-35-challenged neuronal cells, and negatively controlled by SOX21-AS1. miR-132 knockdown abolished the effect of SOX21-AS1 silencing on Aß25-35-induced neuronal damage, indicating that SOX21-AS1 controls Aß25-35-induced neuronal damage via regulating miR-132. The PI3K/AKT signaling was repressed in Aß25-35-challenged cells, but this effect was counteracted upon overexpression of miR-132. In conclusion, SOX21-AS1 knockdown mitigated Aß25-35-dependent neuronal cell damage by promoting miR-132/PI3K/AKT pathway.


Asunto(s)
Péptidos beta-Amiloides/farmacología , Neuronas/efectos de los fármacos , Fragmentos de Péptidos/farmacología , ARN Largo no Codificante/metabolismo , Transducción de Señal/efectos de los fármacos , Apoptosis/efectos de los fármacos , Apoptosis/fisiología , Línea Celular , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/fisiología , Silenciador del Gen , Humanos , MicroARNs/metabolismo , Estrés Oxidativo/efectos de los fármacos , Estrés Oxidativo/fisiología , Fosfatidilinositol 3-Quinasas/metabolismo , Proteínas Proto-Oncogénicas c-akt/metabolismo , ARN Largo no Codificante/genética , Transducción de Señal/fisiología , Regulación hacia Arriba/efectos de los fármacos
2.
Materials (Basel) ; 17(13)2024 Jun 26.
Artículo en Inglés | MEDLINE | ID: mdl-38998213

RESUMEN

While Portland cement produces large amounts of carbon dioxide, low-calcium high-strength cements effectively reduce carbon emissions by decreasing the proportion of high-calcium minerals. In order to enhance the practical application value of low-calcium high-strength cement, the effects of mineral admixtures on the chloride binding capacity and pore structure characteristics of low-calcium high-strength cement pastes were investigated by equilibrium method and mercury intrusion method. The results showed that the chloride binding capacity of low-calcium high-strength cement pastes is superior to that of Portland cement. Fly ash and slag enhance this capacity by promoting monosulfoaluminate and C-S-H gel formation, with fly ash being more effective. Ground limestone also boosts chloride binding when incorporated at less than 10 wt%. However, sulfates have a more significant negative impact on chloride binding capacity in low-calcium high-strength cement pastes compared to Portland cement. The porosity of low-calcium high-strength cement pastes exhibits contrasting trends with the addition of fly ash, ground limestone, and slag. Fly ash and limestone initially coarsen the pore structure but later facilitate the transition of larger pores to smaller ones. In contrast, slag initially has little impact but later promotes the conversion of large capillary pores to medium ones, optimizing the pore structure. Notably, above 10 wt% fly ash, the critical pore diameter decreases with additional fly ash except at 10% where it increases for 3 days. Ground limestone enlarges the critical pore diameter, and this effect intensifies with higher content. During early hydration, slag decreases the critical pore diameter, but its impact diminishes in later stages.

3.
IEEE Trans Cybern ; 53(12): 7834-7843, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37015602

RESUMEN

The problem of event-triggered resilient filtering for Markov jump systems is investigated in this article. The hidden Markov model is used to characterize asynchronous constraints between the filters and the systems. Gain uncertainties of the resilient filter are the interval type in this article, which is more accurate than the norm-bounded type to model the uncertain phenomenon. The number of linear matrix inequalities constraints can be decreased significantly by separating the vertices of the uncertain interval, so that the difficulty of calculation and calculation time can be reduced. Moreover, the event-triggered scheme is applied to depress the consumption of network resources. In order to find a balance between reducing bandwidth consumed and improving system performance, the threshold parameter is designed as a diagonal matrix in the event-triggered scheme. Utilizing the convex optimization method, the sufficient conditions are derived to guarantee that the filtering error systems are stochastically stable and satisfy the extended dissipation performance. Finally, a single-link robot arm system is delivered to certify the effectiveness and advantages of the proposed method.

4.
Environ Sci Pollut Res Int ; 28(26): 34762-34775, 2021 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-33660171

RESUMEN

Gaseous formaldehyde present indoors is often in low-medium concentration, as compared to that contained in manufactured products, but still poses great threat to human health. Thus, this work aims to fabricate Ce-Eu/TiO2 hollow microspheres, which showed excellent photocatalytic performance toward formaldehyde. Furthermore, photocatalytical degradation performance of Ce-Eu/TiO2 hollow microspheres toward formaldehyde was investigated. The kinetics of degradation mechanism of gaseous formaldehyde for different concentrations and different temperatures vs time were studied, and the simulation and experimental results were also compared. It was found that formaldehyde concentration had an effect on the degradation process, which was consistent with different kinetics reactions. At low concentration, the degradation rate was decided by the adsorption rate, and no accumulation of adsorbent occurred. This process was consistent with the first-order kinetics law, which was established by L-H dynamics theory and Arrhenius equation. At medium concentration, the degradation process of formaldehyde was controlled by both adsorption and photocatalysis, which was consistent with the power law model. The 3D model of formaldehyde degradation process by Ce-Eu/TiO2 hollow microspheres at different concentrations vs time was established, and the results showed that the simulation equations were in good agreement with the experimental results.


Asunto(s)
Gases , Titanio , Catálisis , Formaldehído , Humanos , Microesferas
5.
Materials (Basel) ; 13(23)2020 Dec 04.
Artículo en Inglés | MEDLINE | ID: mdl-33291544

RESUMEN

The deformation and cracking of concrete will lead to various deterioration processes, which will greatly reduce the durability and service life of the concrete pavement. The relating previous studies and analysis revealed that the coupling action of environmental temperature, moisture, and wheel load will cause cracking and seriously affect the normal service and durability of pavement concrete. This paper presents theoretical and numerical state-of-the-art information in the field of deformation and failure of pavement concrete under coupling action of moisture, temperature, and wheel load and draws some conclusions. (a) Concrete is a typical porous material, moisture and heat transfer theory has obtained enough data to simulate the hygro-thermo properties of concrete, and the relationship between moisture and heat is very clear. (b) There are few studies on concrete pavement or airport pavement considering the coupling action of moisture, temperature, and wheel load. (c) Concrete pavement is subjected to hygro-thermal-mechanical coupling action in service, which has the characteristics of a similar period and its possible fatigue effect. (d) COMSOL software has certain advantages for solving the coupled hygro-thermal-mechanical of concrete.

6.
Materials (Basel) ; 13(3)2020 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-32019117

RESUMEN

Cracks caused by environmental temperature and humidity variation are generally considered one of the most important factors causing durability deterioration of concrete structures. The seasonal or daily variation of ambient temperature and humidity can be considered periodic. The dynamic modulus of elasticity is an important parameter used to evaluate the performance of structural concrete under periodic loads. Hence, in this paper, the dynamic elastic modulus test of concrete under simulating periodic temperature-humidity variation is carried out according to monthly meteorological data of representative areas (Nanjing, China). The dynamic elastic modulus attenuation pattern and a dynamic elastic modulus degradation model of concrete under periodic temperature-humidity are investigated. The test results show that the dynamic elastic modulus of concrete decreases and tends to be stable under the action of periodic temperature-humidity. Comparative analysis shows that the two-parameter dynamic elastic modulus degradation model is more suitable for describing the dynamic elastic modulus attenuation pattern of concrete under periodic temperature-humidity action than the single-parameter one.

7.
Materials (Basel) ; 13(1)2019 Dec 20.
Artículo en Inglés | MEDLINE | ID: mdl-31861771

RESUMEN

A crack caused by shrinkage could remarkably increase the permeability, heavily deteriorate the durability, and heavily deteriorate the service life of a concrete structure. However, different forms of thermal shrinkage can be predicted by directly applying a temperature load on a node. The prediction of moisture-induced stresses in cement-based materials by using the common finite element method (FEM) software is a big challenge. In this paper, we present a simple numerical calculation approach by using the proposed coefficient of hygroscopic expansion (CHE) to predict the moisture-induced deformation of concrete. The theoretical calculation formula of the linear CHE (LCHE) of cement-based material was deduced based on the Kelvin-Laplace equation and the Mackenzie equation. The hygroscopic deformation of cement mortar was investigated by inversion analysis; based on the results, the LCHE could be determined. Moreover, a case analysis of the application of LCHE to concrete is also conducted. The simulated results of concrete shrinkage were close to the experimental ones. As a whole, it is feasible to predict the drying shrinkage of concrete through simple calculation by using the proposed LCHE, which is also beneficial to the direct application of moisture loads on nodes in finite element analysis (FEA).

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA