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1.
J Colloid Interface Sci ; 660: 834-844, 2024 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-38277840

RESUMO

Catalysts play a pivotal role in advanced oxidation processes for the remediation of organic wastewater. In this study, a 3D carbon fiber@Fe3O4-CuO catalyst was fabricated, and its efficacy for persulfate activation to remove sulfamethoxazole (SMX) was investigated at extremely low current density. The results of characterization revealed that the catalyst was uniformly distributed on the carbon fiber, and the loaded catalyst was Fe3O4-CuO nanoparticles with a diameter range of 20-50 nm. The SMX removal rate was significantly enhanced at extremely low current density by the metallic oxide catalyst loaded on carbon fiber. Approximately 90 % of SMX was degraded within 90 min when the electric current density was set at 0.1 mA cm-2. This modification process not only improved the persulfate activation efficiency but also enhanced the generation of hydrogen peroxide. Both radical and non-radical pathways were involved in the degradation of SMX. The degradation pathway mainly included hydroxylation, carboxylation, aniline cleavage, and desulfonation reactions. The quantitative structure-activity relationship model indicated that the potential risk of intermediate products to fish, daphnia, and green algae significantly decreased during the electrocatalytic oxidation process. This study provides a novel strategy for persulfate activation, which can significantly enhance the degradation efficiency, toxicity abatement, and energy usage effectiveness of electrocatalytic technology.

2.
Sensors (Basel) ; 22(23)2022 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-36501808

RESUMO

As an essential part of intelligent monitoring, behavior recognition, automatic driving, and others, the challenge of multi-object tracking is still to ensure tracking accuracy and robustness, especially in complex occlusion environments. Aiming at the issues of the occlusion, background noise, and motion state violent change for multi-object in a complex scene, an improved DeepSORT algorithm based on YOLOv5 is proposed for multi-object tracking to enhance the speed and accuracy of tracking. Firstly, a general object motion model is devised, which is similar to the variable acceleration motion model, and a multi-object tracking framework with the general motion model is established. Then, the latest YOLOv5 algorithm, which has satisfactory detection accuracy, is utilized to obtain the object information as the input of multi-object tracking. An unscented Kalman filter (UKF) is proposed to estimate the motion state of multi-object to solve nonlinear errors. In addition, the adaptive factor is introduced to evaluate observation noise and detect abnormal observations so as to adaptively adjust the innovation covariance matrix. Finally, an improved DeepSORT algorithm for multi-object tracking is formed to promote robustness and accuracy. Extensive experiments are carried out on the MOT16 data set, and we compare the proposed algorithm with the DeepSORT algorithm. The results indicate that the speed and precision of the improved DeepSORT are increased by 4.75% and 2.30%, respectively. Especially in the MOT16 of the dynamic camera, the improved DeepSORT shows better performance.

3.
Front Nutr ; 9: 898674, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35711557

RESUMO

Cordyceps militaris is a parasitic edible fungus and has been used as tonics for centuries. Polysaccharides are a major water-soluble component of C. militaris. Recently, C. militaris-derived polysaccharides have been given much attention due to their various actions including antioxidant, anti-inflammatory, anti-tumor, anti-hyperlipidemic, anti-diabetic, anti-atherosclerotic, and immunomodulatory effects. These bioactivities are determined by the various structural characteristics of polysaccharides including monosaccharide composition, molecular weight, and glycosidic linkage. The widespread use of advanced analytical analysis tools has greatly improved the elucidation of the structural characteristics of C. militaris-derived polysaccharides. However, the methods for polysaccharide structural characterization and the latest findings related to C. militaris-derived polysaccharides, especially the potential structure-activity relationship, have not been well-summarized in recent reviews of the literature. This review will discuss the methods used in the elucidation of the structure of polysaccharides and structural characteristics as well as the signaling pathways modulated by C. militaris-derived polysaccharides. This article provides information useful for the development of C. militaris-derived polysaccharides as well as for investigating other medicinal polysaccharides.

4.
Sensors (Basel) ; 22(11)2022 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-35684785

RESUMO

Amid increasing demands for planetary exploration, wide-range autonomous exploration is still a great challenge for existing planetary rovers, which calls for new planetary rovers with novel locomotive mechanisms and corresponding control strategies. This paper proposes a novel wheeled-legged mechanism for the design of planetary rovers. The leg suspension utilizes a rigid-flexible coupling mechanism with a hybrid serial-parallel topology. First, the kinematic model is derived. Then, a control strategy for the wheeled-legged rover that includes a trajectory tracking module based on the model predictive control, the steering strategy, and the wheel speed allocation algorithm is proposed. After that, three groups of cosimulations with different trajectories and speeds, and experiments are carried out. Results of both the simulations and experiments validate the proposed control method.


Assuntos
Modelos Teóricos , Robótica , Algoritmos , Fenômenos Biomecânicos , Planetas , Robótica/métodos
5.
Int J Biol Macromol ; 205: 76-89, 2022 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-35181328

RESUMO

Polysaccharides coded as CP were extracted from Athyrium Multidentatum (Doll.) Ching and then fractionated into five fractions (FP-1, FP-2, FP-3, FP-4 and FP-5). A purified polysaccharide designated as FP-3-4 was prepared from FP-3 by Sephadex G-100 column chromatography. Chemical analysis disclosed that CP and these fractions were heteropolysaccharides and mainly composed of glucose, galactose, arabinose, mannose, rhamnose, xylose, fucose, ribose and uronic acid with different molar ratios. They presented different images of SEM. FP-3-4 was highly branched polymers with sixteen types of linkages. The in vitro immunomodulatory results stated that CP and these fractions could promote macrophage proliferation, enhance macrophage phagocytosis and increase the production of NO, TNF-α, IFN-γ, IL-1ß, IL-6, IL-10 and IL-2, indicating remarkable immune enhancement activities. RNA sequencing analysis revealed that CP and FP-3 induced macrophage activation mainly through MAPK and alternative NF-κΒ signaling pathways via CD14/TLR4 and Dectin-2 receptors, which were verified by RT-qPCR and western blot.


Assuntos
Fucose , Polissacarídeos , Animais , Arabinose , Galactose/análise , Manose/análise , Camundongos , Polissacarídeos/química , Polissacarídeos/farmacologia , Células RAW 264.7
6.
Artigo em Inglês | MEDLINE | ID: mdl-34886061

RESUMO

The photocatalytic degradation of minocycline was studied by using polyvinylidene fluoride-polyvinylpyrrolidone-TiO2 (PVDF-PVP-TiO2) fiber mats prepared by an electrospinning technology. The influences of the TiO2 dosage, minocycline concentrations, inorganic anions, pH values, and dissolved organic matter (DOM) concentrations on the degradation kinetics were investigated. A mass of 97% minocycline was degraded in 45 min at 5% TiO2 dosage. The corresponding decomposition rate constant was 0.069 min-1. The inorganic anions affected the minocycline decomposition in the order of HCO3- > Cl- > SO42- > NO3-, which was confirmed by the results of electron spin resonance (ESR) spectra. The lowest electrical energy per order (EEO) was 6.5 Wh/L. Over five cycles, there was no change in the photocatalytic performance of the degrading minocycline. Those investigations suggested that effective degradation of minocycline could be reached in the PVDF-PVP-TiO2 fiber mats with a low energy consumption, good separation and, good recovery. Three photocatalytic decomposition pathways of minocycline were proposed: (i) hydroxyl substitution of the acylamino group; (ii) hydroxyl substitution of the amide group, and (iii) a cleavage of the methyl groups and further oxidation of the amino group by OH. Potential risks caused by TP159 and TP99 should not be ignored, while the TP90 are nontoxic. Tests indicated that the toxicity of the photocatalytic process may be persistent if minocycline and its products were not mineralized completely.


Assuntos
Matéria Orgânica Dissolvida , Minociclina , Adsorção , Catálise , Polímeros de Fluorcarboneto , Cinética , Polivinil , Titânio
7.
Oncol Lett ; 22(2): 591, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34149902

RESUMO

MicroRNAs (miRNAs) are involved in the development of non-small cell lung cancer (NSCLC). However, the biological roles of several aberrantly expressed miRNAs have not been explored yet. In the present study, miR-4491 was identified as a novel upregulated miRNA in NSCLC tissues and cell lines. Downregulation of miR-4491 by a miR-4491 inhibitor inhibited the proliferation and triggered the apoptosis of NSCLC cells. Tripartite motif containing 7 (TRIM7), a tumor suppressor gene expressed in NSCLC, was demonstrated in the present study to be directly targeted by miR-4491. This finding was verified by bioinformatics analysis, reverse transcription-quantitative PCR, western blotting and dual luciferase reporter assays. Furthermore, downregulation of miR-4491 inactivated nuclear factor-κB signaling via induction of TRIM7. In addition, TRIM7 silencing attenuated the effect of miR-4491 inhibitor in NSCLC cells. The decreased TRIM7 level in NSCLC tissues was negatively correlated with miR-4491 expression in NSCLC tissues. In conclusion, the findings from this study demonstrated that miR-4491 expression was upregulated in NSCLC tissues and cells and that miR-4491 may promote NSCLC progression via targeting TRIM7.

8.
J Hazard Mater ; 398: 122827, 2020 11 05.
Artigo em Inglês | MEDLINE | ID: mdl-32768810

RESUMO

Peroxymonosulfate (PMS) can be activated by various catalysts to degrade organic contaminants in wastewater treatment processes. In this research, the co-activation of PMS by sulfamethoxazole (SMX) and carbonate is investigated. The results show that SMX can be degraded in situ, and the main reactive oxygen species are singlet oxygen and carbonate radicals. Only singlet oxygen is detected when SMX is degraded by PMS without carbonate. However, both carbonate radicals and hydroxyl radicals are measured in the presence of carbonate. Among which, hydroxyl radicals are identified by electron paramagnetic resonance spectroscopy method, and carbonate radicals are confirmed by radical quenching experiments, as well as the variation of SMX degradation kinetic and the appreance of carbonyldioxy derivatives by-products in the presence of carbonate anions. Based on this phenomenon, it is proposed that carbonate can enhance the decomposition of PMS and the generation of secondary free radicals (carbonate radicals). Thus carbonate radicals can enhance the oxidizability for sulfonamide antibiotics in the PMS-based advanced oxidation systems. These results suggest that the addition of carbonate is an important enhancement method for the treatment of sulfonamide antibiotics in water.


Assuntos
Sulfametoxazol , Poluentes Químicos da Água , Carbonatos , Peróxidos
9.
Chem Eng J ; 3942020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-33414675

RESUMO

Three novel persulfate activators, Fe(II)-based metal-organic frameworks (MOFs) were synthesized for the degradation of sulfamethoxazole (SMX). The degradation experiment results showed that all the Fe(II)MOFs could effectively activate persulfate and degrade more than 97% SMX within 180 min, with higher than 77% persulfate decomposition efficiencies. It was found by Mössbauer spectra that the variation of organic ligands for synthesis have an influence on the content of Fe(II) of these MOFs, thus resulted in the order of activation capacities: Fe(Nic) > Fe(PyBDC) > Fe(PIP). It was demonstrated that the activation of persulfate was mainly ascribed to the heterogeneous process that accomplished by surface-bounded Fe(II) acted as the main active site to provided electrons for persulfate or dissolved oxygen. EPR and molecular probe studies confirmed the coexistence of SO4·-, ·OH, and O2·-, and differentiated their contributions in SMX degradation. Possible degradation pathways of SMX were proposed based on the detection results of intermediates by UPLC-MS/MS. This work provides a new prospect into the synthesis of high-performance MOFs with strong electron-donating properties as efficient persulfate activators, which may encourage the employ of MOFs in the wastewater treatment process.

10.
Sensors (Basel) ; 19(20)2019 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-31658608

RESUMO

In this paper, a mobile anchor node assisted RSSI localization scheme in underwater wireless sensor networks (UWSNs) is proposed, which aims to improve location accuracy and shorten location time. First, to improve location accuracy, we design a support vector regression (SVR) based interpolation method to estimate the projection of sensor nodes on the linear trajectory of the mobile anchor node. The proposed method increases the accuracy of the nonlinear regression model of noisy measured data and synchronously decreases the estimation error caused by the discreteness of measured data. Second, to shorten location time, we develop a curve matching method to obtain the perpendicular distance from sensor nodes to the linear trajectory of the mobile anchor node. The location of the sensor node can be calculated based on the projection and the perpendicular distance. Compared with existing schemes that require the anchor node to travel at least two trajectories, the proposed scheme only needs one-time trajectory to locate sensor nodes, and the location time is shortened with the reduction in the number of trajectories. Finally, simulation results prove that the proposed scheme can obtain more accurate sensor node location in less time compared with the existing schemes.

11.
Chemosphere ; 237: 124495, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31394452

RESUMO

A regeneration method for porous electrospun membranes embedding alumina nanoparticles saturated with minocycline was investigated by UV-LED system. The percentage of adsorption capacities before and after regeneration were used to evaluate regeneration efficiency. The PVDF and PVDF-Al2O3 fiber mats were prepared by electrospinning technique. Scanning electron microscope (SEM), transmission electron microscope (TEM), energy-dispersive X-ray spectroscopy (EDS) analyses directly confirmed that Al2O3 nanoparticles were generally exposed to the surface of PVDF-Al2O3 fiber mats. Among them, PVDF-Al2O3 10% fiber mats can effectively adsorb minocycline (remove efficiency >97% in 18 h) with first-order rate constant k = 2.253 ±â€¯0.331 h-1. The sorption capacity can still keep 81% after five sorption/UV-regeneration circulations. Two successional stages may exist during regeneration: (i) transfer of minocycline from the surface of PVDF-Al2O3 fibers to the DI water, followed by the (ii) decomposition of this compound in aqueous solution by direct and indirect photolysis to yield the intermediate species. The desorption capacity and desorption percentage were 4.39 mg g-1 and 23.30% respectively. The regeneration yields were further enhanced to 94.20% by UV radiation. Minocycline was effectively degraded to intermediate products by direct and indirect photolysis, further degraded into CO2, H2O, and NOx by UV-generated ozone during regeneration. The results indicated that UV radiation was an effective method of regenerating PVDF-Al2O3 fiber mats with low energy requirements. The photochemical byproducts and the reaction sites during regeneration were also determined and recognized.


Assuntos
Óxido de Alumínio/química , Minociclina/química , Nanopartículas/química , Adsorção , Membranas , Fotólise , Porosidade , Raios Ultravioleta , Água/química , Poluentes Químicos da Água/análise
12.
Psychophysiology ; 56(4): e13313, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30561786

RESUMO

Individuals rely on various frames of reference (FORs), such as an egocentric FOR (EFOR) and intrinsic FOR (IFOR), to represent spatial information. Previous behavioral studies have shown different IFOR-IFOR (II) and EFOR-IFOR (EI) conflict effects and an effect of their interaction. However, the neural mechanism of conflict processing between two FOR-based conflicts is unclear. In the current ERP study, two FOR-based conflicts were manipulated using a two-cannon task to elucidate common and distinct brain mechanisms that underlie FOR-based conflict processing. The behavioral results showed that both conflicts exhibited longer reaction times and larger error rates in the II (180° cannon angle) and EI (target cannon pointed down) incongruent conditions than in the II (0° cannon angle) and EI (target cannon pointed up) congruent conditions and that an interaction existed between the two conflicts. The ERP results indicated that, for both conflicts, more negative N2 amplitudes and less positive P3 amplitudes occurred in the incongruent conditions than in the congruent conditions, and the interactions between the two conflicts during later P3 amplitudes were significant. Time-frequency analysis further indicated that, in the early time window, the II conflict and the EI conflict specifically modulated power in the theta bands and beta bands, respectively. In contrast, in the later time window, both conflicts modulated power in the alpha and beta bands. In summary, our findings provide insights into the potential existence of two specific early conflict monitoring systems and a general late executive control system for FOR-based conflicts.


Assuntos
Ondas Encefálicas/fisiologia , Córtex Cerebral/fisiologia , Conflito Psicológico , Potenciais Evocados/fisiologia , Função Executiva/fisiologia , Desempenho Psicomotor/fisiologia , Adolescente , Adulto , Potenciais Evocados P300/fisiologia , Feminino , Humanos , Masculino , Tempo de Reação/fisiologia , Fatores de Tempo , Adulto Jovem
13.
Environ Sci Pollut Res Int ; 25(23): 22818-22828, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29855882

RESUMO

The regeneration of adsorbent by thermal method may transfer the adsorbed organic pollutants into the air phase. Herein, manganese and cerium are loaded on adsorbent as catalyst to mineralize the adsorbed organic pollutants during regeneration. The modified adsorbent is characterized by scanning electron microscope-energy dispersive spectrometer, Brunauer Emmett Teller-Barrett Joyner Halenda, and X-ray photoelectron spectroscopy. Regeneration of modified adsorbent is evaluated by adsorbent yield and mineralization percentage of the absorbed organic pollutants. The results demonstrate that the mineralization percentage of tetracycline increased about 100% after the modification. Besides, the loaded catalyst can significantly reduce the regeneration temperature. Furthermore, cerium can reduce the adverse impact causes by manganese which will decrease the adsorption capacity of adsorbent. Kinetics, equilibrium, thermodynamic, and other adsorption properties of modified adsorbent towards tetracycline are further studied. The theoretical maximum of adsorption capacity calculated by Langmuir model is 196.4 mg g-1, and the kinetics of adsorption fits pseudo-second-order model. The adsorption of tetracycline on the adsorbent is feasible, spontaneous, and endothermic. The properties of synthesized composite material are stable; the yield of Ce/Mn/Al2O3 adsorbent can keep higher than 95% even after five adsorption/regeneration cycles. This research provides another perspective on the design and regeneration of adsorbent, which focus on reducing the secondary pollution during adsorbent regeneration process.


Assuntos
Óxido de Alumínio/química , Cério/química , Manganês/química , Tetraciclina/química , Poluentes Químicos da Água/química , Adsorção , Cinética , Microscopia Eletrônica de Varredura , Espectroscopia Fotoeletrônica , Temperatura , Tetraciclina/isolamento & purificação , Termodinâmica , Eliminação de Resíduos Líquidos/instrumentação , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/isolamento & purificação
14.
Environ Sci Pollut Res Int ; 25(1): 290-298, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29034423

RESUMO

To decrease the secondary pollution of volatile organic compounds (VOCs) during adsorbent regeneration by microwave, electrodeless lamp was added in the microwave field to oxidize VOCs in the gas phase. Ultraviolet has a significant improvement on mineralization of VOCs generated from adsorbate during adsorbent regeneration. However, the mechanism and main influence factors on the degradation of VOCs are not clear. The effect of microwave power, regeneration time, airflow rate, and humidity content on the mineralization of adsorbed tetracycline during adsorbent regeneration was studied. Ozone concentration and ultraviolet irradiation intensity were also measured to analyze the mechanism of the microwave-ultraviolet adsorbent regeneration method. Although the electrodeless lamp adsorbed microwave and competed with the regenerated adsorbent, the mineralization percentage of tetracycline increased about 10% with the presence of electrodeless lamp at the same microwave power supply. Besides, humidity content also takes an important role on enhancing the mineralization of tetracycline. The mineralization of tetracycline in the microwave-ultraviolet field consists of three major parts: pyrolysis, ozone oxidation, and free radical oxidation. More than 50% adsorbed tetracycline can be oxidized into H2O and CO2 during regeneration in 5 min. These results support the potential use of electrodeless lamp to treat VOCs in the gas phase to decrease the risk of secondary pollution during adsorbent regeneration.


Assuntos
Poluentes Atmosféricos/análise , Carvão Vegetal/efeitos da radiação , Micro-Ondas , Raios Ultravioleta , Compostos Orgânicos Voláteis/análise , Adsorção , Carvão Vegetal/química , Oxirredução , Ozônio/química
15.
Psych J ; 5(4): 256-262, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28032476

RESUMO

People rely on multiple frames of reference (FORs) to represent and update spatial relationships of different objects in a complex environment. According to the "Frame of Reference-based Map of Salience" theory (FORMS), FORs with high salience are processed in priority, and human performance is determined by the interaction of all relevant FOR-based representations. We conducted a modified two-cannon task manipulating conflicts among FORs (e.g., egocentric [FOR-EFOR], intrinsic [FOR-IFOR]) in order to explore how FORs interact with each other. We found that participants responded slower when two IFORs were incongruent than when they were congruent. There was also an interaction between these two conflicts. Moreover, the effect size of conflict between two IFORs was much larger than that between an IFOR and an EFOR. These results suggest that although the IFOR and EFOR may be coded by different spatial representations, they rely on a common processing mechanism and compete with each other. The findings from the current study provide support for the FORMS theory.


Assuntos
Processos Mentais , Percepção Espacial , Humanos
17.
Int J Biol Macromol ; 76: 326-9, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25773592

RESUMO

High sulfate content derivative of polysaccharide (HU) from Ulva pertusa (Chlorophyta) showed strong antioxidant activity in vitro. In the present study, in vivo antioxidant activity were tested in liver of hyperlipidemic rats including malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and catalase (CAT). The HU groups at the doses of 125 mg/kg and 250 mg/kg showed stronger activity on SOD than hyperlipidemimia group (P<0.01). The HU groups at the doses of 125 mg/kg and 500 mg/kg could increase the activities of GSH-Px obviously (P<0.01) as compared with hyperlipidemic rats. It was likely that the sulfate content had significant effect on the antioxidant activity in vivo. On the other hand, it may be concluded that, probably due to its antioxidant effects, HU is effective in the protection of liver tissue from the damage of cholesterol-rich diet rats and that the HU may be of use as an antihyperlipidemia agent.


Assuntos
Antioxidantes/química , Antioxidantes/farmacologia , Polissacarídeos/química , Sulfatos/química , Animais , Feminino , Hipolipemiantes/química , Hipolipemiantes/farmacologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Oxirredução/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Polissacarídeos/farmacologia , Ratos , Baço/efeitos dos fármacos , Baço/metabolismo , Superóxido Dismutase/metabolismo
18.
Proc Natl Acad Sci U S A ; 112(12): 3788-92, 2015 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-25775565

RESUMO

People generally fail to produce random sequences by overusing alternating patterns and avoiding repeating ones-the gambler's fallacy bias. We can explain the neural basis of this bias in terms of a biologically motivated neural model that learns from errors in predicting what will happen next. Through mere exposure to random sequences over time, the model naturally develops a representation that is biased toward alternation, because of its sensitivity to some surprisingly rich statistical structure that emerges in these random sequences. Furthermore, the model directly produces the best-fitting bias-gain parameter for an existing Bayesian model, by which we obtain an accurate fit to the human data in random sequence production. These results show that our seemingly irrational, biased view of randomness can be understood instead as the perfectly reasonable response of an effective learning mechanism to subtle statistical structure embedded in random sequences.


Assuntos
Comportamento , Teorema de Bayes , Córtex Cerebral/patologia , Jogo de Azar , Humanos , Aprendizagem , Modelos Neurológicos , Modelos Estatísticos , Neocórtex/patologia , Rede Nervosa , Neurônios/fisiologia , Dinâmica não Linear , Probabilidade , Fatores de Tempo
19.
Carbohydr Polym ; 108: 41-5, 2014 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-24751245

RESUMO

Different molecular weight polysaccharides were prepared by degradation of polysaccharides extracted from Athyrium multidentatum (Doll.) Ching rhizome (CPA) with hydrogen peroxide and ascorbic acid. Four low molecular polysaccharides derivatives (CPA-1, CPA-2, CPA-3 and CPA-4) were successfully obtained and had their antioxidant activities investigated employing various established in vitro systems. All CPA derivatives showed pronounced antioxidant activity, and had stronger antioxidant ability than CPA in certain tests. CPA-1 exhibited the strongest scavenging ability on 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical among all samples, and the IC50 value was 25 µg/mL. CPA-2 possessed the highest scavenging ability against superoxide radical at 200 µg/mL. The scavenging activity of CPA-4 on hydroxyl radical was higher than CPA from 120 to 200 µg/mL. The mechanism on influence the antioxidant activity of CPA and its degraded derivatives was indicated.


Assuntos
Antioxidantes/química , Gleiquênias/química , Polissacarídeos/química , Peso Molecular , Espécies Reativas de Oxigênio/química
20.
Front Hum Neurosci ; 8: 58, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24592226

RESUMO

Recent research has seen a growing interest in connections between domains of spatial and social cognition. Much evidence indicates that processes of representing space in distinct frames of reference (FOR) contribute to basic spatial abilities as well as sophisticated social abilities such as tracking other's intention and belief. Argument remains, however, that belief reasoning in social domain requires an innately dedicated system and cannot be reduced to low-level encoding of spatial relationships. Here we offer an integrated account advocating the critical roles of spatial representations in intrinsic frame of reference. By re-examining the results from a spatial task (Tamborello etal., 2012) and a false-belief task (Onishi and Baillargeon, 2005), we argue that spatial and social abilities share a common origin at the level of spatio-temporal association and predictive learning, where multiple FOR-based representations provide the basic building blocks for efficient and flexible partitioning of the environmental statistics. We also discuss neuroscience evidence supporting these mechanisms. We conclude that FOR-based representations may bridge the conceptual as well as the implementation gaps between the burgeoning fields of social and spatial cognition.

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