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21.
Tunneling nanotubes (TNTs) are recognized long membrane nanotubes connecting distance cells. In the last decade, growing evidence has shown that these subcellular structures mediate the specific transfer of cellular materials, pathogens, and electrical signals between cells. As intercellular bridges, they play a unique role in embryonic development, collective cell migration, injured cell recovery, cancer treatment resistance, and pathogen propagation. Although TNTs have been considered as potential drug targets for treatment, there is still a long way to go to translate the research findings into clinical practice. Herein, we emphasize the heterogeneous nature of TNTs by systemically summarizing the current knowledge on their morphology, structure, and biogenesis in different types of cells. Furthermore, we address the communication efficiency and biological outcomes of TNT-dependent transport related to diseases. Finally, we discuss the opportunities and challenges of TNTs as an exciting therapeutic approach by focusing on the development of efficient and safe drugs targeting TNTs.  相似文献   
22.
通过对荔浦市境内碳酸盐岩区岩质崩塌及该区域地质环境条件的调查,总结了岩质崩塌的规模、发育高度、控制结构面等发育特征,分析了岩质崩塌形成条件,并判断岩质崩塌的失稳运动特征。本文以一处危岩为例,用无人机进行三维扫描并分析其形成原因及预测其失稳运动特征。  相似文献   
23.
贾承造 《石油学报》2021,41(12):1445-1464
石油和天然气是全球和中国最重要的一次能源。石油工业的生存发展是由油气资源、市场、技术和社会政治经济环境等要素决定的,其中,技术进步是最活跃和最关键的因素之一。中国已成为全球油气生产消费大国,中国石油工业上游的发展也高度依赖石油科技的进步。中国石油工业已形成了先进完整的理论技术研发和装备制造体系,支撑了油气产量持续稳产和增产。未来是中国社会经济发展的关键期,石油工业必将面对重大挑战与新的技术需求,大力实施国家创新战略,发展具有国际领先水平的新一代勘探开发理论技术,支撑油气产业发展,保障国家油气能源安全。中国石油工业上游在未来面临的重大挑战与技术需求包括:①满足中国未来现代化建设的巨大油气需求和保障油气供应安全,这当中必须加大中国油气勘探开发,同时进一步扩大全球及"一带一路"油气投资与生产;②实现中国石油长期稳产2×108t/a以上;③实现中国天然气产量上升至3 000×108m3/a并长期稳产;④发展海洋及深水油气勘探开发先进技术与装备;⑤形成新一代石油工程服务技术装备和数字化转型。中国石油工业上游未来的科技攻关方向和研发重点包括:①先进的石油大幅度提高采收率技术;②大气田勘探与复杂气田提高采收率技术;③非常规油气勘探开发技术;④海洋及深水油气勘探开发技术及装备;⑤"一带一路"油气勘探开发技术;⑥新一代石油工程服务技术装备和数字化转型。  相似文献   
24.
人体大脑和身体的发育,需要从食物中摄取均衡的营养物质。人类大脑是区分人类和其他动物的特征。食物中的必需脂肪酸是机体组织结构和功能的必要组成部分。Omega-6(O6)亚油酸(LA6)是皮肤组织的组成成分,且是炎症、血栓形成、免疫和其他信号分子的前体;Omega-3(O3)α-亚麻酸(ALA3),特别是其长链代谢产物——二十二碳六烯酸(DHA3),是大脑、视网膜和部分神经组织中的关键组分。从富含LA6脂肪酸(缺乏O3脂肪酸)的植物籽中提取出的廉价而优质油脂,是20世纪的西方国家食品工业生产的主要脂肪来源。在代谢通路中,高浓度的LA6脂肪酸可拮抗O3脂肪酸代谢,造成O3脂肪酸不足,因此,在给怀孕动物的饲料中,只提供富含LA6但缺乏O3脂肪酸的油脂作为唯一的脂肪来源,会导致幼崽大脑发育不良。过去20~30年的研究表明,低含量LA6且含DHA3的油脂可改善大脑的功能。近年来的研究较多集中在营养因素对大脑发育的影响,最新研究数据表明,脂肪酸平衡对营养不良儿童的大脑发育尤为重要。世界卫生组织(WHO)越来越重视大脑的营养健康,通过其下属的食品法典委员会,建议用于治疗严重急性营养不良儿童的即食治疗食品中,使用含有均衡脂肪酸组成/构成的脂肪。同样,脂肪酸均衡对老年人可能也很重要。目前,业界已经有了调整油脂成分的方法,以确保脂肪酸均衡,从而维持人体整个生命周期的大脑健康。  相似文献   
25.
Urban development has an important influence on the energy consumption of transportation. To develop public transportation is one of the important ways to decrease the energy consumption of urban transportation. It is very urgent to upgrade technology to reduce the energy consumption and emissions of the vehicles constantly. The popularization of hydrogen fuel cell vehicles is the trend of the future automobile industry, which can effectively reduce traffic energy consumption and alleviate urban pollution. This article analyzes the impact of urban development on public transport and private transportation energy consumption from 2013 to 2015; and uses hydrogen fuel cell vehicles alternatives in urban public transport as a scenario. It shows that urban economic development can effectively reduce public transport. Population growth will increase greatly energy consumption of public transport, while larger cities with reasonable spatial density can reduce traffic energy consumption. Moreover, hydrogen fuel cell vehicles can effectively reduce the energy consumption and pollution emissions of urban transportation during operating. Based on the above conclusions, this article will eventually provide targeted recommendations for the development of Chinese cities, public transport, and hydrogen fuel cell vehicles.  相似文献   
26.
This study develops a crisis self‐efficacy index to provide a tool for crisis communication researchers and practitioners to understand behavioural aspects of crisis response better. Evaluations of public's crisis self‐efficacy using this index inform strategic message development to protect the public and minimize crisis damages by identifying the public/s most in need of self‐efficacy enhancing interventions. The index also provides practitioners a useful longitudinal index to evaluate progress in crisis preparedness programs and track changes in efficacy. A four‐stage survey index development process using structural equation modelling identifies four underlying constructs of crisis self‐efficacy: action, preventive, achievement and uncertainty management.  相似文献   
27.
Digital technology becomes more powerful, intelligent, pervasive and ubiquitous. Ethical aspects of this development have not yet drawn the appropriate attention of researchers and engineers. This paper presents an instrument that aims at measuring the individual ethical position with regard to the design and development of computer software. The development of the Epos tool was based on two data collections. The data of the first survey (n1 = 147 participants) were used to select items and to determine the factorial structure of the questionnaire. Results show that the Epos instrument reliably assesses peoples’ ethical opinion with respect to five central components: (1) regulation, (2) data privacy, (3) domain specific knowledge, (4) societal responsibility and (5) company responsibility. In the second survey, we determined the stability of the instruments factor structure by assessing a sample of n2?=?196 participants. A confirmatory factor analysis (CFA) supported the initial factor structure. Next steps and further implications are discussed regarding the final version of the questionnaire.  相似文献   
28.
29.
Refurbishment and quality recovery, as two important strategies of reverse logistics, have been widely used for consumer durables, especially consumer electronics. This trend is driven by manufacturers’ profit-seeking behaviours and the increasing environmental concerns of society. This study investigates and compares the optimal emergence of these two strategies when product quality is endogenous. Model analyses provide several notable insights. First, we find that the refurbishment strategy dominates the quality recovery strategy when the fraction of the recoverable quality-inducing components in the defective product is low enough. Moreover, when the refurbishment strategy emerges as the optimum, the quality and price of the new product as well as the total realised sales of both new and refurbished products are consistently higher than those with the quality recovery strategy. In addition, when either the refurbishment or quality recovery strategy emerges as the optimum, the overall consumer surplus is also enhanced. Finally, in the model generalisation, we show that a synthetic strategy with which some of the returned defective products are refurbished and others are remanufactured through quality recovery can certainly increase the manufacturers’ profit compared to either one of them when the fraction of the recoverable quality-inducing components in the defective product is moderate.  相似文献   
30.
Few jurisdictions have translated internationally agreed social impact assessment (SIA) principles into statutory provisions. Governments and regulatory bodies tend to provide developers with high-level frameworks, or require that social impacts be ‘considered’, without specifying how this is to be done. In Australia, this lack of clarity leaves all parties uncertain about requirements for SIA. The New South Wales (NSW) Government’s 2017 release of the SIA guideline for State-significant mining, petroleum and extractive industry development represents an attempt to clarify requirements and provide guidance. In this paper, we describe the process of bringing this guideline to fruition from the perspective of being directly involved in its development, and highlight the challenges involved in integrating leading-practice principles into the state’s pre-existing policy framework. While the guideline represents a significant advance in policy-based SIA guidance, some aspects leave room for improvement. The real test of the guideline’s impact will lie in its influence on SIA practice in NSW, and ultimately in social outcomes for communities affected by resources projects.  相似文献   
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