Search

神经酸是一种能够疏通、修复受损神经纤维和促进神经细胞再生的单不饱和脂肪酸，可用于预防及治疗脑萎缩、阿尔茨海默病等脑疾病，具有较高的药用价值。旨在为高纯度神经酸产品的生产和发展提供参考，综述了神经酸的功效和来源，详细阐述了植物来源神经酸的分离方法，包括其原理和特点。不同分离方法的耦合可克服单一分离方法的某些缺点，且一定程度上解决对神经酸纯度、产量双重提高的难题，成为重要的研究方向。Nervonic acid is a monounsaturated fatty acid that can unblock and repair damaged nerve fibers and promote nerve cell regeneration, so it can be used to prevent and treat brain diseases such as brain atrophy and Alzheimer′s disease, and has high medicinal value. In order to provide reference for the production and development of high-purity nervonic acid products, the efficacy and sources of nervonic acid were reviewed, and the separation methods of nervonic acid, including their principles and characteristics were described. The coupling of different methods can overcome some disadvantages of single separation method, solve the problem of improving the purity and yield of nervonic acid to a certain extent, which has become an important research direction for the separation of nervonic acid.

Various nutrient requirements of soil microorganisms often occur in restoration ecosystems, but the responses of microbial communities in different vegetation types remain unclear. In this study, we selected four types of vegetation (grassland desert (GD), desert steppe (DS), typical steppe (TS), and artificial forest (AF)) on the Mu Us Desert, and examined the soil physicochemical properties, extracellular enzyme activities (carbon (C)-, nitrogen (N)-, and phosphorus (P)-acquisition enzymes), and community characteristics. Our results revealed that the N-requirement of microorganisms in the area was higher than that of other elements, particularly when organic C was scarce, whereas severe P requirement was detected in the presence of abundant organic matter. Compared with TS, we detected a higher diversity of microorganisms in GD, DS, and AF, and the microbial communities were dominated by a few taxa with loose internal connections and higher C and N requirements. Stronger N and P requirements reduced the diversity of microorganisms and the relative abundance of dominant taxa in TS, but increased the stability of bacterial communities. Our results further indicate that bacteria play a more active role in coping with the transformation of nutrient requirements. When C- and N-requirements of microorganisms were transformed to N and P, the abundance of dominant and sub-dominant taxa decreased and increased, respectively. Collectively, the results of this study indicate that efficient vegetation restoration in desert areas may lead to stronger nutrient requirements for microorganisms, thus reducing the diversity of microorganisms and causing unpredictable consequences for ecological sustainable development.

Research Findings: This study investigated the sequential mediating effects of parental material investment (MI) and time investment (TI) upon the correlation between family socioeconomic status (SES) and toddlers' development (TD). Data derived from a 2016 data set, including a sample of 1,316 toddlers based in 117 villages across 22 counties within northwestern China, were utilized. Parents completed the Bayley Scales of Infant and Toddler Development III (BSID-III) and Ages & Stages Questionnaires: Social-Emotional (ASQ: SE). The mediation analysis revealed: (1) a significant positive correlation among family SES, parental material investment, time investment, and the development of toddlers aged 0–3 years; (2) family SES indirectly impacted toddlers' development through the singular mediating pathway of material investment significantly, and the single mediating path of time investment was found to be insignificant; and (3) both material investment and time investment were recognized as the sequential mediators between family SES and toddler development. Practice or Policy: The study's findings underscore the aspects of parental material and time investment that optimally support toddlers' development. These results may also guide the structure and implementation of family interventions and policies designed to reduce the developmental disparity among toddlers from families of differing SES. [ABSTRACT FROM AUTHOR]

In 1998, the People's Republic of China implemented an education policy, the "School Consolidation Policy", which entailed merging small rural schools with larger ones. It has had a massive effect on rural people across China, and as a result of it, over 60% of schools in outlying areas have closed. The policy's implementation and effects have received little scholarly attention, despite its scale and consequences. This article investigates the policy, drawing on the nexus between critical discourse analysis and an ethnographical study conducted from 2007 to 2018. The article reviews trajectories and critical junctures shaping educational change in one rural community in north-western China, as an example of broader changes that have been occurring across the country. This is presented through four thematically interrelated episodes, over a 10-year period, illustrating the conception of the policy, its local interpretation and implementation, and its consequences as perceived by stakeholders. The recontextualisation of rural education is part of the policy, as expressed in political discourse, and is examined together with its wider impacts. Attention is paid to the local adoption of the policy at different levels of government and the challenges faced by villagers in rural China in their efforts to capitalise on educational opportunities and secure a measure of social mobility. Consequences of the policy's implementation are analysed and include rising educational inequality, social marginalisation and a lack of social mobility prospects for families affected.

The distribution pattern of cracks in rock masses, known as the geometric distribution, holds significant significance in understanding the progressive failure mechanism and stress concentration can lead to instability and even failure of the specimens. However, the macroscopic and microscopic mechanisms of crack coalescence and the failure of the sample are not yet clear. Thus, the discrete element method was used to investigate the influence of stress distribution on the fracture coalescence and failure of dual-crack specimens with different arrangements under uni-axial compression in this study. The obtained results were compared and analyzed with laboratory test results. The results show: When the double-crack specimens are under overlapping arrangement, the stress concentration area only appears at the end of the crack, which is conducive to crack propagation, resulting in no coalescence. However, if the two preexisting cracks were arranged in a co-planar or non-overlapping manner, the stress concentration of the sample would not only occur at the end of the cracks, but also between the cracks. As the stress increases, the cracks will gradually expand and connect, forming shear coalescence and mixed mode coalescence (shear and tensile) respectively. In addition, the arrangement of cracks greatly changes the influence of stress concentration on the failure mode of the specimen, leading to the possibility that the coalescence of the specimen may occur in three periods: before, during, and after the peak stress. The findings of this research hold immense importance in comprehending the mechanisms behind the coalescence and failure of rock fractures. Moreover, they provide valuable insights for the analysis and design of rock engineering projects, offering practical guidance for ensuring stability. [ABSTRACT FROM AUTHOR]

AbstractDuring seasonal rainfall periods, natural rocks typically undergo repeated wetting-drying cycles, which directly affects the micro-structure of the rock samples and consequently leads to the deterioration of their mechanical properties, especially in mudstone. Therefore, this paper investigated the degradation pattern of strength parameters and failure pattern of mudstone samples under wetting-drying cycles through a series of laboratory tests and quantitatively characterized the micro-structural changes in the samples. Additionally, numerical simulations were utilized to delve deeper into the degradation mechanism of the samples. The results indicate that with an increasing number of wetting-drying cycles, the degradation of peak strength and elastic modulus becomes more pronounced. Moreover, there is a continuous increase in micro-porosity within the samples, accompanied by changes in pore structure and morphology. According to the simulation results, the wetting-drying cycles change how the samples fail, transitioning from mixed tensile-shear failure to predominantly shear failure. This study not only deepens the theoretical understanding of the deterioration mechanisms in mudstone but also provides important guidance for practical applications. [ABSTRACT FROM AUTHOR]

Background: Exosomes in cardiovascular diseases (CVDs) have attracted huge attention with substantial value and potential. Our bibliometrics is based on literature from the field of cardiovascular exosomes over the past 30 years, which has been visualized to display the development process, research hotspots, and cutting-edge trends of clinical practices, mechanisms, and management strategies related to psych cardiology. Methods: We selected articles and reviews on exosomes in CVDs from the core collection of Web of Science, and generated visual charts by using CiteSpace and VOSviewer software. Results: Our research included 1613 publications. The number of exosome articles in CVD fluctuates slightly, but overall shows an increasing trend. The main research institutions were Tongji University and Nanjing Medical University. The International Journal of Molecular Sciences has the highest publication volume, while the Journal of Cellular and Molecular Medicine has the highest citation count. Among all the authors, Eduardo Marban ranks first in terms of publication volume and H-index. The most common keywords are exosome, extracellular vesicles, and angiogenesis. Conclusion: This is a bibliometric study on the research hotspots and trends of exosomes in CVD. Exosome research in the field of cardiovascular medicine is on the rise. Some exosome treatment methods may become the focus of future research. [ABSTRACT FROM AUTHOR]