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Ferrihydrite (Fh) has been demonstrated acting as a hole-storage layer (HSL) in photoelectrocatalysis system. However, the intrinsic structure responsible for the hole storage function for Fh remains unclear. Herein, by dehydrating the Fh via a careful calcination, the essential relation between the HSL function and the structure evolution of Fh material is unraveled. The irreversible and gradual loss of crystal water molecules in Fh leads to the weakening of the HSL function, accompanied with the arrangement of inner structure units. A structure evolution of the dehydration process is proposed and the primary active structure of Fh for HSL is identified as the [FeO6 ] polyhedral units bonding with two or three molecules of crystal water. With the successive loss of chemical crystal water, the coordination symmetry of [FeO6 ] hydration units undergoes mutation and a more ordered structure is formed, causing the difficulty for accepting photogenerated holes as a consequence.
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A small molecule library of N-acyl-substituted 1,2-benzisothiazol-3-one derivatives has been synthesized and evaluated as inhibitors of caspase-3 and -7, in which some of them showed nanomolar potency against caspase-3 and -7 in vitro. Meanwhile, in 10 lM concentration, both compounds 24 and 25 showed significant protection against apoptosis in camptothecin-induced Jurkat T cells system. The docking studies predicted the interactions and binding modes of the synthesized inhibitors in the caspase-3 active site.
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Caspase 3/metabolismo , Inibidores de Caspase/síntese química , Tiazóis/química , Apoptose/efeitos dos fármacos , Sítios de Ligação , Camptotecina/toxicidade , Caspase 3/química , Caspase 7/química , Caspase 7/metabolismo , Inibidores de Caspase/química , Inibidores de Caspase/farmacologia , Domínio Catalítico , Humanos , Células Jurkat , Simulação de Acoplamento Molecular , Ligação Proteica , Relação Estrutura-Atividade , Tiazóis/síntese química , Tiazóis/farmacologiaRESUMO
Play is an effective approach to engaging children in learning as an alternative to traditional lecturing. The Learning through Play (LtP) approach involves various modes of learning participation, including multi-sensory participation, interpersonal interaction, and hands-on operation, which can effectively motivate children to learn. This study implemented an LtP pilot survey in several first-tier cities of China, which included questionnaires and interviews. The results present the basic ecology of LtP in China, LtP effects on children's multimodal learning. We found that LtP has gained great popularity, both conceptually and practically, in China. LtP stakeholders recognize the behavioral, cognitive, and affective effectiveness of LtP for children's learning. The factors influencing the effectiveness of LtP include its structural weaknesses, the subjects involved, the environment, and culture. This study provides a reference for promoting the theory and practice of children's multimodal learning with a playful approach.
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Recent development of surface electromyogram (sEMG) decomposition technique provides a good basis of decoding movements from individual motor unit (MU) activities that directly representing microscopic neural drives. How to interpret the function and contribution of each decomposed MU to macroscopic movements remains unclear. The objective of this study is to decode finger movement patterns by establishing a relationship between individual MU activities and movements. In this study, high-density sEMG (HD-sEMG) data were recorded by a 16 × 8 electrode array from finger extensor muscles of 10 subjects performing 10 finger movement patterns. The progressive FastICA peel-off algorithm was first applied to decompose the HD-sEMG data to obtain microscopic neural drives in terms of MU firing sequences and their corresponding action potential waveforms. Then, convolutional neural network was used for classification of the decomposed MUs by characterizing their spatial waveforms spanned over all channels of the array. On this basis, a fuzzy weighted decision strategy was designed to give a final decision of movement pattern recognition, where function of an individual MU was measured in the form of contributing into all movement patterns with different weights to solve the issue of MUs shared among multiple patterns due to muscle co-activation. The proposed method yielded an average accuracy approximating to 100%, and it outperformed other common MU-based methods or conventional myoelectric classification methods using macroscopic sEMG features (p < 0.05). The proposed method has a wide application prospect in the field of human-machine interaction and precise motor control.
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Aprendizado Profundo , Algoritmos , Eletromiografia , Dedos/fisiologia , Humanos , MovimentoRESUMO
To study the economic and environmental effects of human capital, previous studies measure human capital based on education; however, this approach has many shortcomings because not all educated people are innovative human capital. Hence, this study introduces the concept of innovative human capital by developing a new index that measures human capital based on the number of patents every one million R&D staff full-time equivalent. After this, this paper studies the impact of innovative human capital on CO2 emissions in China. The provincial panel data of 30 Chinese provinces from 2003 to 2017 is analyzed using the fixed effect, ordinary least squares, and the system generalized method of moments (SYS-GMM). The analysis revealed that innovative human capital alleviates environmental deterioration in China. The findings unfold the existence of the environmental Kuznets curve (EKC) considering innovative human capital in the model. It implies that Chinese economic development will eventually support environmental sustainability if China continues to develop its innovative human capital. Among the control variables, economic structure, population density, and energy intensity stimulate environmental degradation by increasing CO2 emissions. However, FDI has a negative relationship with CO2 emissions. Lastly, the study proposes comprehensive policies to increase innovative human capital for environmental sustainability.
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Dióxido de Carbono , Desenvolvimento Econômico , Dióxido de Carbono/análise , China , Poluição Ambiental/análise , Humanos , Investimentos em SaúdeRESUMO
Both insulin resistance (type II diabetes) and beta-amyloid (Abeta) oligomers are implicated in Alzheimer's disease (AD). Here, we investigate the role of Abeta oligomer-induced c-Jun N-terminal kinase (JNK) activation leading to phosphorylation and degradation of the adaptor protein insulin receptor substrate-1 (IRS-1). IRS-1 couples insulin and other trophic factor receptors to downstream kinases and neuroprotective signaling. Increased phospho-IRS-1 is found in AD brain and insulin-resistant tissues from diabetics. Here, we report Abeta oligomers significantly increased active JNK and phosphorylation of IRS-1 (Ser616) and tau (Ser422) in cultured hippocampal neurons, whereas JNK inhibition blocked these responses. The omega-3 fatty acid docosahexaenoic acid (DHA) similarly inhibited JNK and the phosphorylation of IRS-1 and tau in cultured hippocampal neurons. Feeding 3xTg-AD transgenic mice a diet high in saturated and omega-6 fat increased active JNK and phosphorylated IRS-1 and tau. Treatment of the 3xTg-AD mice on high-fat diet with fish oil or curcumin or a combination of both for 4 months reduced phosphorylated JNK, IRS-1, and tau and prevented the degradation of total IRS-1. This was accompanied by improvement in Y-maze performance. Mice fed with fish oil and curcumin for 1 month had more significant effects on Y-maze, and the combination showed more significant inhibition of JNK, IRS-1, and tau phosphorylation. These data indicate JNK mediates Abeta oligomer inactivation of IRS-1 and phospho-tau pathology and that dietary treatment with fish oil/DHA, curcumin, or a combination of both has the potential to improve insulin/trophic signaling and cognitive deficits in AD.
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Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/farmacologia , Curcumina/farmacologia , Inibidores Enzimáticos/farmacologia , Ácidos Graxos Ômega-3/farmacologia , Proteínas Substratos do Receptor de Insulina/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Neurônios/efeitos dos fármacos , Fragmentos de Peptídeos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Proteínas tau/metabolismo , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/dietoterapia , Doença de Alzheimer/patologia , Precursor de Proteína beta-Amiloide/genética , Animais , Comportamento Animal , Células Cultivadas , Curcumina/uso terapêutico , Modelos Animais de Doenças , Embrião de Mamíferos , Inibidores Enzimáticos/uso terapêutico , Ácidos Graxos Ômega-3/uso terapêutico , Hipocampo/citologia , Humanos , Camundongos , Camundongos Transgênicos , Pessoa de Meia-Idade , Fosforilação/efeitos dos fármacos , Mudanças Depois da Morte , Presenilina-1/genética , Ratos , Ratos Sprague-Dawley , Serina/metabolismoRESUMO
Graphitic carbon nitride (g-C3N4) was prepared by a simple thermal polymerization method in this work. The effects of precursor type, thermal polymerization temperature, constant temperature time and atmosphere on the crystal structure, morphology, elemental composition, valence distribution, light absorption properties and photocatalytic activity of the prepared photocatalytic materials were investigated. Taking rhodamine B (RhB) as the target degradant, the blue light catalytic activity of the photocatalytic material was studied in detail. The experimental results showed that the final pyrolysis temperature and constant temperature time are positively related to the adsorption characteristics and photocatalytic ability of the prepared materials. In addition, the adsorption capacity and photocatalytic activity of the products obtained in Ar and H2 atmospheres are better than those produced in CO and CH4, which can be attributed to the combined effect of large specific surface area and structural defects of the materials. The sample's large specific surface area, wide band gap, and excellent photogenerated carrier separation and transfer capabilities make the adsorption performance and photocatalytic performance of the products obtained with ammonium thiocyanate and thiourea as precursors better than those prepared from melamine and dicyandiamide. g-C3N4 prepared by using ammonium thiocyanate as precursor at 550 °C for 5 h under a hydrogen atmosphere showed the best catalytic activity for the degradation of RhB under blue light. It was demonstrated that g-C3N4 prepared exhibited good stability and reusability after four repeat experiments. The active components that play major roles in the degradation of RhB described herein were holes and superoxide radicals, which was inferred by free radical trapping experiments. This work provides a theoretical basis for the idea of converting the mixed salts of desulfurization waste liquid containing ammonium thiocyanate into an excellent photocatalyst g-C3N4 with visible light response.
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In the growing market of health food, certain disturbances occur, such as uneven quality of products, imitation of health food, prohibited drug content in health food, functional efficacy, and actual disagreement. The safety of health food has attracted wide attention from all walks of life. In this study, we constructed a three-party game model of health food safety risk evolution, which includes health food enterprises, health food consumers, and government regulators, based on prospect theory and evolutionary game method. We also consider the attributes of "trust products" of health food, the ability to identify the safety information of health food, the subjective perception of the efficacy of health food, and the certification effect of the regulatory information of the government supervision department. The influence mechanism of these factors, including the cost of searching for health food information, consumers' subjective perception of health food efficiency, and the certification effect of supervision departments, on health food safety risk evolution is described using theoretical deduction and simulation analysis. On this basis, the corresponding conclusions are established, which provide a theoretical basis for further exploration of the strategy of health food market governance.
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Comportamento do Consumidor , Inocuidade dos Alimentos , Comportamentos Relacionados com a Saúde , Modelos Teóricos , Alimentos/economia , Alimentos/normas , Preferências Alimentares , Humanos , Política Nutricional , RiscoRESUMO
Charge separation is one of the most critical factors for generating solar fuels via photoelectrochemical water splitting, but it is still not well understood. This work reveals the fundamental role of charge transfer in photoanodes for achieving high charge separation efficiency. Specifically, we fabricated a particulate Ta3N5 photoanode by a bottom-up method. By improving the charge separation with refined necking treatment, the photocurrent is increased by two orders of magnitude. The charge separation efficiency (ηsep) is analyzed by dividing it into charge generation efficiency (Φgene) and transportation efficiency (Φtrans). Necking treatment is found to substantially improve the electron transfer. Transient photovoltage (TPV) measurements based on the Dember effect is used to confirm the benefit of necking treatment in improving the charge transportation. The superior electron transfer in the necked-Ta3N5 electrode is further evidenced by the facile electron exchange reaction with the ferri/ferrocyanide redox couple. Moreover, cobalt phosphate is found to promote both charge separation and surface reaction, resulting in a photocurrent of 6.1 mA cm-2 at 1.23 V vs. RHE, which is the highest response for a particulate photoanode.
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Lithium transitionmetal (Fe, Mn, Co, Ni) silicate cathode materials are new promising substituting cathode materials for lithium ion batteries. They had caught the researchers' eyes in the past several years. Nowadays, there are growing interests for silicate cathode materials in the field of lithium ion batteries. Among the silicate cathode materials, Li2FeSiO4 is the most promising cathode materials because of its high structure stability, high reversible capacity, high electronic conductivity and the abundant resource of iron and silicon. Although Li2MnSiO4 and Li2CoSiO4 have much higher theoretic specific capacity than Li2FeSiO4, they all have inferior electrochemical behaviours due to different reasons. There are only calculation results about Li2NiSiO4 till now. This brief critical review firstly discussed some papers about the first-principle calculation of Li2MSiO4 (M=Fe, Mn, Co Ni), and then collects and discusses relevant papers and recent patents about the fabrication, structure, particle size and electrochemical performance of nano/micro Li2MSiO4 (M=Fe, Mn, Co Ni) and their composites. Finally, the future challenges of Li2FeSiO4 are also discussed.