Tea is widely consumed all over the world. Generally, tea is divided into six categories: White, green, yellow, oolong, black, and dark teas, based on the fermentation degree. Tea contains abundant ...phytochemicals, such as polyphenols, pigments, polysaccharides, alkaloids, free amino acids, and saponins. However, the bioavailability of tea phytochemicals is relatively low. Thus, some novel technologies like nanotechnology have been developed to improve the bioavailability of tea bioactive components and consequently enhance the bioactivity. So far, many studies have demonstrated that tea shows various health functions, such as antioxidant, anti-inflammatory, immuno-regulatory, anticancer, cardiovascular-protective, anti-diabetic, anti-obesity, and hepato-protective effects. Moreover, it is also considered that drinking tea is safe to humans, since reports about the severe adverse effects of tea consumption are rare. In order to provide a better understanding of tea and its health potential, this review summarizes and discusses recent literature on the bioactive components, bioavailability, health functions, and safety issues of tea, with special attention paid to the related molecular mechanisms of tea health functions.
Summary
Aims
Ferroptosis, a new form of iron‐dependent programmed cell death, has been shown to be involved in a range of diseases. However, the role of ferroptosis in traumatic brain injury (TBI) ...has yet to be elucidated. We aimed to investigate whether ferroptosis is induced after TBI and whether the inhibition of ferroptosis would protect against traumatic brain injury in a controlled cortical impact injury (CCI) mouse model.
Methods
After establishing the TBI model in mice, we determined the biochemical and morphological changes associated with ferroptosis, including iron accumulation with Perl's staining, neuronal cell death with Fluoro‐Jade B (FJB) staining, iron metabolism dysfunction with Western blotting, reactive oxygen species (ROS) accumulation with malondialdehyde (MDA) assays, and shrunken mitochondria with transmission electron microscopy. Furthermore, a specific inhibitor of ferroptosis, ferrostatin‐1(fer‐1), was administrated by cerebral ventricular injection after CCI. We used cresyl violet (CV) staining to assess lesion volume, along with the Morris water maze and beam walk test to evaluate long‐term outcomes.
Results
TBI was followed by iron accumulation, dysfunctional iron metabolism, the upregulation of ferroptosis‐related genes, reduced glutathione peroxidase (GPx) activity, and the accumulation of lipid‐reactive oxygen species (ROS). Three days (d) after TBI, transmission electron microscopy (TEM) confirmed that the mitochondria had shrunk a typical characteristic of ferroptosis. Importantly, the administration of Fer‐1 by cerebral ventricular injection significantly reduced iron deposition and neuronal degeneration while attenuating injury lesions and improving long‐term motor and cognitive function.
Conclusion
This study demonstrated an effective method with which to treat TBI by targeting ferroptosis.
Evolutionary feature selection (FS) methods face the challenge of "curse of dimensionality" when dealing with high-dimensional data. Focusing on this challenge, this article studies a variable-size ...cooperative coevolutionary particle swarm optimization algorithm (VS-CCPSO) for FS. The proposed algorithm employs the idea of "divide and conquer" in cooperative coevolutionary approach, but several new developed problem-guided operators/strategies make it more suitable for FS problems. First, a space division strategy based on the feature importance is presented, which can classify relevant features into the same subspace with a low computational cost. Following that, an adaptive adjustment mechanism of subswarm size is developed to maintain an appropriate size for each subswarm, with the purpose of saving computational cost on evaluating particles. Moreover, a particle deletion strategy based on fitness-guided binary clustering, and a particle generation strategy based on feature importance and crossover both are designed to ensure the quality of particles in the subswarms. We apply VS-CCPSO to 12 typical datasets and compare it with six state-of-the-art methods. The experimental results show that VS-CCPSO has the capability of obtaining good feature subsets, suggesting its competitiveness for tackling FS problems with high dimensionality.
Abstract
As interpretation courses are generally offered in colleges and universities, French interpretation courses not only reflect the similarities between French interpretation courses and ...English interpretation courses, but also have many special features. With the development of science and technology, artificial intelligence translation tools are also the product of social development, which has a vital influence on both interpretation work and interpretation teaching. This paper not only introduces the situation of artificial intelligence translation products, but also introduces its influence on French interpretation teaching, which is the representative of minority language, especially it plays an important role. This paper also introduces methods on how to cultivate talents who are suitable for the current situation of social development, These talents should not only with high-level interpretation skills, but also with diversified and compound skills.
Obvious biases in simulating tropical cyclone (TC) genesis of the current climate models hamper our understanding of TC changes. In this study, we found a delay of the seasonal cycle of TC genesis ...frequency over the western North Pacific (WNP) in most Coupled Model Intercomparison Project Phase 6 models. During the active TC season, the simulated south‐warming and north‐cooling surface temperature bias amplifies the meridional gradient and excites thermal winds. This weakens the western North Pacific Subtropical High and easterly monsoon trough, which further reduces TC genesis frequency over the western WNP in summer. But in autumn, positive TC genesis biases were only observed in coupled models over the eastern WNP. Both seasons contribute to the delayed seasonal cycle of TC frequency in models. Our findings highlight the importance of accurate simulation of surface temperature by climate models to TC simulations and aid in future model improvements.
Plain Language Summary
Tropical cyclone (TC) is a devastating weather system generated over the tropical ocean, and the climate model serves as an important tool to study the long‐term variability of TC activity. Hence, it is imperative to explore the biases of climate models in simulating TC genesis. In this investigation, we find a substantial influence of surface temperature bias in Coupled Model Intercomparison Project Phase 6 (CMIP6) climate models on the simulation of the seasonal cycle of TC genesis frequency over the western North Pacific (WNP). The delay in the seasonal cycle of TC genesis frequency is widespread among most CMIP6 models. During boreal summer and autumn, the simulated bias of south‐warming and north‐cooling surface temperature increases its meridional gradient and triggers thermal winds. In summer, the weak western North Pacific Subtropical High and easterly monsoon trough, two crucial large‐scale circulation systems, cause a large negative TC genesis bias in models over the western WNP, substantially contributing to the delay of the seasonal cycle. Meanwhile, the relatively small positive bias of coupled models over the eastern WNP in autumn makes a secondary contribution. The combined contributions of these biases cause delays in seasonal simulation of TC genesis frequency.
Key Points
Coupled Model Intercomparison Project Phase 6 models produce delayed seasonal cycles of tropical cyclone genesis frequency over the western North Pacific
Biases in East Asia summer monsoon and western North Pacific subtropical high lead to underestimation of tropical cyclone genesis during summer
The biased large‐scale circulation systems are further related to a warm southern and cold northern surface temperature bias
The El Niño-Southern Oscillation (ENSO) can significantly affect the rapid intensification of tropical cyclones over the western North Pacific (WNP). However, ENSO events have various durations, ...which can lead to different atmospheric and oceanic conditions. Here we show that during short duration El Niño events, the WNP tropical cyclone rapid-intensification mean occurrence position migrates westward by ~8.0° longitude, which is caused by reduced vertical wind shear, increased mid-tropospheric humidity, and enhanced tropical cyclone heat potential over the westernmost WNP. The changes in these factors are caused by westward advected upper ocean heat during the decaying phase of a short duration El Niño. As super El Niño events tend to have short durations and their frequency is projected to increase under global warming, our findings have important implications for future projections of WNP tropical cyclone activity.
Smart cities have been a global concern in recent years, involving comprehensive scientific research. To obtain a structural overview and assist researchers in making insights into the ...characteristics of smart cities research, bibliometric analysis was carried out in this paper. With the application of the bibliometric analysis software VOSviewer and CiteSpace, 4409 smart cities were identified by the core collection of the Web of Science in publications between 1998 and 2019 and used in the analysis of this paper. Concretely, this research visually demonstrates a comprehensive overview of the field relating to smart cities in terms of the production of regular publications, main domain of smart cities researchers, most influential countries (institutions, sources and authors), and interesting research directions in the smart city researches. We also present the research collaboration among countries (regions), organizations and authors based on a series of cooperation analyses. The bibliometric analysis of the existing work provided a valuable and seminal reference for researchers and practitioners in smart cities-related research communities.
Under the new round of scientific and technological revolution and industrial change, the integration of vocational education and industry is an important direction of educational development. In ...this paper, the structure of the learning path network of higher vocational professional courses is analyzed, and through the analysis of the elements of learning behaviors, the learning behaviors are mined by adopting sequence relations, and the behavioral structure model is established. The assessment of the learning path under the integration of industry and education courses was finished using uncertainty association coefficients and time association coefficients. After building the learning path network for vocational education, the subjective characteristics of students under vocational education were detected using isolated point analysis. The detection results show that the correlation coefficient between the first pair of typical variables is 0.488. The Wilks statistical test results for typical correlation coefficients show that the p-value of the first typical correlation coefficient is 0.098, which is less than 10%. The correlation study of the environment of integration of education and industry and the effect of integration can be simplified to study only the relationship between the first pair of typical variables. By analyzing the main characteristics, the main body for vocational education and industry integration is clarified, which creates a digital-driven impetus for the integration of industry and education.
Tin diselenide (SnSe2) nanosheets as novel 2D layered materials have excellent optical properties with many promising application prospects, such as photoelectric detectors, nonlinear optics, ...infrared photoelectric devices, and ultrafast photonics. Among them, ultrafast photonics has attracted much attention due to its enormous advantages; for instance, extremely fast pulse, strong peak power, and narrow bandwidth. In this work, SnSe2 nanosheets are fabricated by using solvothermal treatment, and the characteristics of SnSe2 are systemically investigated. In addition, the solution of SnSe2 nanosheets is successfully prepared as a fiber‐based saturable absorber by utilizing the evanescent field effect, which can bear a high pump power. 31st‐order subpicosecond harmonic mode locking is generated in an Er‐doped fiber laser, corresponding to the maximum repetition rate of 257.3 MHz and pulse duration of 887 fs. The results show that SnSe2 can be used as an excellent nonlinear photonic device in many fields, such as frequency comb, lasers, photodetectors, etc.
Tin diselenide (SnSe2) nanosheets as novel 2D layered materials have excellent optical properties. SnSe2 nanosheets fabricated by using solvothermal treatment are successfully prepared as fiber‐based saturable absorbers by utilizing the evanescent field effect, which can bear a high pump power. 31st‐order subpicosecond harmonic mode‐locking is generated, corresponding to 257.3 MHz repetition rate.
PDF
