Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Chem Commun (Camb) ; 58(51): 7120-7123, 2022 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-35642961

RESUMO

A novel and facile strategy for fabricating red phosphorus@nitrogen doped graphene/carbon nanotube aerogel (P@NGCA) is proposed as a free-standing anode for high energy sodium-ion batteries. Owing to an optimized structure of red P uniformly confined in porous NGCA with high conductivity and mechanical stability, the free-standing P@NGCA anode exhibits outstanding sodium storage performance with a high areal capacity of 3.3 mA h cm-2 and superior initial Coulombic efficiency of 80%.

2.
Eur J Pharmacol ; 911: 174539, 2021 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-34599913

RESUMO

Ischemia heart disease, one of the lethal cardiovascular diseases, irreversibly impairs cardiac function and is recognized as the primary risk factor for mortality in industrialized countries. The myocardial ischemia treatment still faces a considerable degree of increasing unmet needs. Isosteviol sodium (STVNa) and its derivatives have been proven to effectively alleviate metabolic diseases, hypertension, and heart hypertrophy. Little is known about how STVNa confers the cardioprotective effect during acute myocardial ischemia (AMI). In the present study, a rat model of acute ST-segment-elevation myocardial ischemia by left anterior descending (LAD) ligation was established. Compared to the AMI model group, STVNa administration (4 mg/kg, twice a day) well preserved left ventricle function by ejection fraction (45.10 ± 10.39 vs. 73.64 ± 13.15, p = 0.0013) and fractional shortening (22.94 ± 6.28 vs. 44.00 ± 11.05, p = 0.0017). Further analysis shows that high-dose STVNa (4 mg/kg) significantly improved the hemodynamics in AMI rats, with LVSP (88.25 ± 12.78 vs 99.75 ± 5.10, p = 0.018), max dP/dt (2978.45 ± 832.46 vs 4048.56 ± 827.23, p = 0.096), LVEDP (19.88 ± 2.00 vs 22.26 ± 3.21, p = 0.04) and left ventricular relaxation time constant (Tau) (0.030 ± 0.006 vs 0.021 ± 0.004, p = 0.021). Mechanically, STVNa administration retained the myocardial levels of phosphorylated AMPK, and CPT1b. Moreover, STVNa significantly increased the total energy expenditure, and reduced fatty acid accumulation through mitochondrial oxidative phosphorylation, which was supported by the indirect calorimetry and cellular energy analysis. Taken together, these findings suggest that STVNa is a potential cardioprotection agent for ischemic cardiomyopathy, likely through improving energy homeostasis, left ventricular hemodynamics, and heart function.


Assuntos
Diterpenos do Tipo Caurano
3.
Chaos ; 31(8): 083107, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34470251

RESUMO

The firing patterns of each bursting neuron are different because of the heterogeneity, which may be derived from the different parameters or external drives of the same kind of neurons, or even neurons with different functions. In this paper, the different electromagnetic effects produced by two fractional-order memristive (FOM) Hindmarsh-Rose (HR) neuron models are selected for characterizing different firing patterns of heterogeneous neurons. Meanwhile, a fractional-order memristor-coupled heterogeneous memristive HR neural network is constructed via coupling these two heterogeneous FOM HR neuron models, which has not been reported in the adjacent neuron models with memristor coupling. With the study of initial-depending bifurcation behaviors of the system, it is found that the system exhibits abundant hidden firing patterns, such as periods with different topologies, quasiperiodic firings, chaos with different topologies, and even hyperchaotic firings. Particularly, the hidden hyperchaotic firings are perfectly detected by two-dimensional Lyapunov stability graphs in the two-parameter space. Meanwhile, the hidden coexisting firing patterns of the system are excited from two scattered attraction domains, which can be confirmed from the local attraction basins. Furthermore, the color image encryption based on the system and the DNA approach owns great keyspace and a good encryption effect. Finally, the digital implementations based on Advanced RISC Machine are in good coincidence with numerical simulations.


Assuntos
Modelos Neurológicos , Redes Neurais de Computação , Análise por Conglomerados , Neurônios
4.
Neural Netw ; 140: 325-335, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33895556

RESUMO

This paper is concerned with the multistability of fractional-order competitive neural networks (FCNNs) with time-varying delays. Based on the division of state space, the equilibrium points (EPs) of FCNNs are given. Several sufficient conditions and criteria are proposed to ascertain the multiple O(t-α)-stability of delayed FCNNs. The O(t-α)-stability is the extension of Mittag-Leffler stability of fractional-order neural networks, which contains monostability and multistability. Moreover, the attraction basins of the stable EPs of FCNNs are estimated, which shows the attraction basins of the stable EPs can be larger than the divided subsets. These conditions and criteria supplement and improve the previous results. Finally, the results are illustrated by the simulation examples.


Assuntos
Redes Neurais de Computação , Tempo
5.
Cogn Neurodyn ; 15(1): 157-167, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33786086

RESUMO

In order to overcome the security weakness of the discrete chaotic sequence caused by small Lyapunov exponent and keyspace, a general chaotic construction method by cascading multiple high-dimensional isomorphic maps is presented in this paper. Compared with the original map, the parameter space of the resulting chaotic map is enlarged many times. Moreover, the cascaded system has larger chaotic domain and bigger Lyapunov exponents with proper parameters. In order to evaluate the effectiveness of the presented method, the generalized 3-D Hénon map is utilized as an example to analyze the dynamical behaviors under various cascade modes. Diverse maps are obtained by cascading 3-D Hénon maps with different parameters or different permutations. It is worth noting that some new dynamical behaviors, such as coexisting attractors and hyperchaotic attractors are also discovered in cascaded systems. Finally, an application of image encryption is delivered to demonstrate the excellent performance of the obtained chaotic sequences.

6.
Chem Commun (Camb) ; 56(45): 6078-6081, 2020 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-32352103

RESUMO

A novel design strategy for synthesizing hard carbon microspheres (HCMs) from a single source of sodium lignin sulfonate is proposed for a practical anode material of sodium-ion batteries. The HCM has an optimized microstructure, including an enlarged interlayer spacing and few defects, along with a low specific surface area. As an anode material of sodium-ion batteries, HCM is highly promising for practical applications because of its high capacity and reversibility.

7.
J Anim Sci ; 97(8): 3426-3439, 2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-31233597

RESUMO

This study was conducted to investigate the effects of Clostridium butyricum addition to diets in late gestation and lactation on the reproductive performance and gut microbiota for sows. A total of 180 healthy Landrace × Yorkshire sows at 90 d of gestation were randomly assigned to one of four groups, with 45 replicates per group, receiving a basal commercial diet (Control, 0% C. butyricum) or diet added with 0.1% C. butyricum (1 × 108 CFU/kg of feed), 0.2% C. butyricum (2 × 108 CFU/kg of feed), 0.4% C. butyricum (4 × 108 CFU/kg of feed), respectively. The experiment was conducted from 90 d of gestation to weaning at 21 d of lactation. The results showed that the interval between piglet born was linearly (P < 0.05) decreased, and the duration of farrowing was significantly (quadratic, P < 0.05) shortened as C. butyricum addition increased. There was a linear (P < 0.05) increase in litter weight at weaning and litter weight gain. The concentrations of IgG and IgM in colostrum, and IgM in milk were linearly increased (P < 0.05) as C. butyricum addition. Serum MDA concentrations of sows at parturition and 14 d in lactation, and piglets at 14 and 21 d of age were linearly (P < 0.05) decreased, respectively. The serum total antioxidant capacity concentrations of sows at parturition and 14 and 21 d in lactation, and piglets at 14 and 21 d of age were linearly (P < 0.05) increased as C. butyricum addition, respectively. There was a linear decrease in the serum endotoxin concentration of sows on 21 d in lactation (P < 0.05). The serum cortisol concentrations of piglets at 14 and 21 d of age were both significantly (quadratic, P < 0.05) decreased. The 0.2% C. butyricum increased the relative abundance of Bacteroidetes (P = 0.016) at phylum level, Prevotellaceae_NK3B31_group, Prevotella_1, Prevotellaceae_UCG-003, Prevotella_9, Alloprevotella (P < 0.05) at genus level, and decreased the relative abundance of Proteobacteria, Gemmatimonadetes, Actinobacteria (P < 0.001) at phylum level, and Clostridium_sensu_stricto_1, Streptococcus, Escheruchia-Shigella, Sphingomonas, Succinivibrio (P < 0.05) at genus level and Firmicutes/Bacteroidetes ratio (P = 0.020). In conclusion, the present research indicated that dietary addition with C. butyricum could shorten the duration of farrowing and enhance the growth performance of suckling piglets. Moreover, 0.2% C. butyricum administration to sows changed the composition of intestinal microbiota, especially increased the relative abundance of Prevotella.


Assuntos
Ração Animal/análise , Clostridium butyricum/fisiologia , Microbioma Gastrointestinal , Reprodução , Suínos/microbiologia , Animais , Antioxidantes/análise , Colostro/imunologia , Dieta/veterinária , Feminino , Imunoglobulina G/imunologia , Imunoglobulina M/imunologia , Intestinos/microbiologia , Lactação , Leite/imunologia , Parto , Gravidez , Suínos/imunologia , Desmame , Aumento de Peso/efeitos dos fármacos
8.
Chaos ; 29(4): 043112, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31042929

RESUMO

In this paper, two different pulse control methods are proposed to generate multi-butterfly attractors based on the Sprott C system. By introducing a bipolar multilevel pulse signal to the boostable variable z of the Sprott C system, translational multi-butterfly attractors with constant Lyapunov exponents can be obtained. Another method for generating nested multi-butterfly attractors is to replace the DC voltage of the Sprott C system with the unipolar multilevel pulse signal, and the dynamical behavior involves the superposition of multiple attractors corresponding to different pulse amplitudes. By defining time as an additional state variable, the proposed non-autonomous systems can be transformed into autonomous systems for analysis. It can be seen that systems have no equilibria, so they belong to hidden attractors. A normalized circuit implementation is given, translational and nested hidden multi-butterfly attractors can be obtained by setting proper pulse signals. Moreover, the number of butterflies can be adjusted by changing the number of pulse voltage sources without reconstructing nonlinear functions. Theoretical analysis and simulation results prove the effectiveness of these methods.

9.
Int J Clin Exp Pathol ; 10(7): 7408-7416, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-31966583

RESUMO

This study was aimed to analyze the association of chemerin/chemR23 with endothelial-mesenchymal transition (EndMT) in the kidney of rats during the progression of diabetic nephropathy (DN). Eighty male Sprague-Dawley rats were randomly distributed to age-matched control and diabetic nephropathy model groups. Diabetes was induced by intraperitoneal injection of streptozotocin (STZ). Morphological changes in the renal tissues were observed after periodic acid-Schiff staining. Chemerin and chemR23 expression was determined by immunohistochemistry. Co-expression of α-smooth muscle actin (α-SMA) and CD31 was determined by immunofluorescence double-labeling. Expression of all these markers was analyzed by Western blotting. Expression of chemerin, chemR23, and transforming growth factor-ß1 (TGF-ß1) genes at mRNA level was determined by qRT-PCR. Mild glomerular hypertrophy was observed at 4 weeks and mild glomerular basement membrane thickening and mesangial matrix proliferation at 12 weeks. Immunohistochemistry showed much higher levels of chemerin and chemR23 in diabetic rats compared with the control group. Expression of chemerin, chemR23, and α-SMA proteins increased with disease progression, while CD31 protein expression decreased. Expression of chemerin, chemR23, and TGF-ß1 mRNAs also increased. α-SMA and CD31 co-expression increased with disease progression from 4 weeks. Spearman correlation analysis showed that chemerin mRNA levels correlated positively with Chem R23, TGF-ß1, α-SMA expression, and CD31 and α-SMA double-positive cell numbers, but negatively with CD31 protein expression. In conclusion, chemerin expression correlates with EndMT in DN model rats.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...